xref: /openbsd-src/gnu/usr.bin/perl/Porting/Glossary (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1
2!!!!!!!   DO NOT EDIT THIS FILE   !!!!!!!
3This file is built by metaconfig.
4
5This file contains a description of all the shell variables whose value is
6determined by the Configure script.  Variables intended for use in C
7programs (e.g. I_UNISTD) are already described in config_h.SH.  [`configpm'
8generates pod documentation for Config.pm from this file--please try to keep
9the formatting regular.]
10
11_a (Unix.U):
12	This variable defines the extension used for ordinary library files.
13	For unix, it is '.a'.  The '.' is included.  Other possible
14	values include '.lib'.
15
16_exe (Unix.U):
17	This variable defines the extension used for executable files.
18	DJGPP, Cygwin and OS/2 use '.exe'.  Stratus VOS uses '.pm'.
19	On operating systems which do not require a specific extension
20	for executable files, this variable is empty.
21
22_o (Unix.U):
23	This variable defines the extension used for object files.
24	For unix, it is '.o'.  The '.' is included.  Other possible
25	values include '.obj'.
26
27afs (afs.U):
28	This variable is set to 'true' if AFS (Andrew File System) is used
29	on the system, 'false' otherwise.  It is possible to override this
30	with a hint value or command line option, but you'd better know
31	what you are doing.
32
33afsroot (afs.U):
34	This variable is by default set to '/afs'. In the unlikely case
35	this is not the correct root, it is possible to override this with
36	a hint value or command line option.  This will be used in subsequent
37	tests for AFSness in the configure and test process.
38
39alignbytes (alignbytes.U):
40	This variable holds the number of bytes required to align a
41	double-- or a long double when applicable. Usual values are
42	2, 4 and 8.  The default is eight, for safety.
43
44ansi2knr (ansi2knr.U):
45	This variable is set if the user needs to run ansi2knr.
46	Currently, this is not supported, so we just abort.
47
48aphostname (d_gethname.U):
49	This variable contains the command which can be used to compute the
50	host name. The command is fully qualified by its absolute path, to make
51	it safe when used by a process with super-user privileges.
52
53api_revision (patchlevel.U):
54	The three variables, api_revision, api_version, and
55	api_subversion, specify the version of the oldest perl binary
56	compatible with the present perl.  In a full version string
57	such as '5.6.1', api_revision is the '5'.
58	Prior to 5.5.640, the format was a floating point number,
59	like 5.00563.
60
61	perl.c:incpush() and lib/lib.pm will automatically search in
62	$sitelib/.. for older directories back to the limit specified
63	by these api_ variables.  This is only useful if you have a
64	perl library directory tree structured like the default one.
65	See INSTALL for how this works.  The versioned site_perl
66	directory was introduced in 5.005, so that is the lowest
67	possible value.  The version list appropriate for the current
68	system is determined in inc_version_list.U.
69
70	XXX To do:  Since compatibility can depend on compile time
71	options (such as bincompat, longlong, etc.) it should
72	(perhaps) be set by Configure, but currently it isn't.
73	Currently, we read a hard-wired value from patchlevel.h.
74	Perhaps what we ought to do is take the hard-wired value from
75	patchlevel.h but then modify it if the current Configure
76	options warrant.  patchlevel.h then would use an #ifdef guard.
77
78api_subversion (patchlevel.U):
79	The three variables, api_revision, api_version, and
80	api_subversion, specify the version of the oldest perl binary
81	compatible with the present perl.  In a full version string
82	such as '5.6.1', api_subversion is the '1'.  See api_revision for
83	full details.
84
85api_version (patchlevel.U):
86	The three variables, api_revision, api_version, and
87	api_subversion, specify the version of the oldest perl binary
88	compatible with the present perl.  In a full version string
89	such as '5.6.1', api_version is the '6'.  See api_revision for
90	full details.  As a special case, 5.5.0 is rendered in the
91	old-style as 5.005.  (In the 5.005_0x maintenance series,
92	this was the only versioned directory in $sitelib.)
93
94api_versionstring (patchlevel.U):
95	This variable combines api_revision, api_version, and
96	api_subversion in a format such as 5.6.1 (or 5_6_1) suitable
97	for use as a directory name.  This is filesystem dependent.
98
99ar (Loc.U):
100	This variable is used internally by Configure to determine the
101	full pathname (if any) of the ar program.  After Configure runs,
102	the value is reset to a plain "ar" and is not useful.
103
104archlib (archlib.U):
105	This variable holds the name of the directory in which the user wants
106	to put architecture-dependent public library files for $package.
107	It is most often a local directory such as /usr/local/lib.
108	Programs using this variable must be prepared to deal
109	with filename expansion.
110
111archlibexp (archlib.U):
112	This variable is the same as the archlib variable, but is
113	filename expanded at configuration time, for convenient use.
114
115archname (archname.U):
116	This variable is a short name to characterize the current
117	architecture.  It is used mainly to construct the default archlib.
118
119archname64 (use64bits.U):
120	This variable is used for the 64-bitness part of $archname.
121
122archobjs (Unix.U):
123	This variable defines any additional objects that must be linked
124	in with the program on this architecture.  On unix, it is usually
125	empty.  It is typically used to include emulations of unix calls
126	or other facilities.  For perl on OS/2, for example, this would
127	include os2/os2.obj.
128
129asctime_r_proto (d_asctime_r.U):
130	This variable encodes the prototype of asctime_r.
131	It is zero if d_asctime_r is undef, and one of the
132	REENTRANT_PROTO_T_ABC macros of reentr.h if d_asctime_r
133	is defined.
134
135awk (Loc.U):
136	This variable is used internally by Configure to determine the
137	full pathname (if any) of the awk program.  After Configure runs,
138	the value is reset to a plain "awk" and is not useful.
139
140baserev (baserev.U):
141	The base revision level of this package, from the .package file.
142
143bash (Loc.U):
144	This variable is defined but not used by Configure.
145	The value is the empty string and is not useful.
146
147bin (bin.U):
148	This variable holds the name of the directory in which the user wants
149	to put publicly executable images for the package in question.  It
150	is most often a local directory such as /usr/local/bin. Programs using
151	this variable must be prepared to deal with ~name substitution.
152
153bin_ELF (dlsrc.U):
154	This variable saves the result from configure if generated binaries
155	are in ELF format. Only set to defined when the test has actually
156	been performed, and the result was positive.
157
158binexp (bin.U):
159	This is the same as the bin variable, but is filename expanded at
160	configuration time, for use in your makefiles.
161
162bison (Loc.U):
163	This variable is used internally by Configure to determine the
164	full pathname (if any) of the bison program.  After Configure runs,
165	the value is reset to a plain "bison" and is not useful.
166
167byacc (Loc.U):
168	This variable is used internally by Configure to determine the
169	full pathname (if any) of the byacc program.  After Configure runs,
170	the value is reset to a plain "byacc" and is not useful.
171
172byteorder (byteorder.U):
173	This variable holds the byte order in a UV. In the following,
174	larger digits indicate more significance.  The variable byteorder
175	is either 4321 on a big-endian machine, or 1234 on a little-endian,
176	or 87654321 on a Cray ... or 3412 with weird order !
177
178c (n.U):
179	This variable contains the \c string if that is what causes the echo
180	command to suppress newline.  Otherwise it is null.  Correct usage is
181	$echo $n "prompt for a question: $c".
182
183castflags (d_castneg.U):
184	This variable contains a flag that precise difficulties the
185	compiler has casting odd floating values to unsigned long:
186	0 = ok
187	1 = couldn't cast < 0
188	2 = couldn't cast >= 0x80000000
189	4 = couldn't cast in argument expression list
190
191cat (Loc.U):
192	This variable is used internally by Configure to determine the
193	full pathname (if any) of the cat program.  After Configure runs,
194	the value is reset to a plain "cat" and is not useful.
195
196cc (cc.U):
197	This variable holds the name of a command to execute a C compiler which
198	can resolve multiple global references that happen to have the same
199	name.  Usual values are 'cc' and 'gcc'.
200	Fervent ANSI compilers may be called 'c89'.  AIX has xlc.
201
202cccdlflags (dlsrc.U):
203	This variable contains any special flags that might need to be
204	passed with 'cc -c' to compile modules to be used to create a shared
205	library that will be used for dynamic loading.  For hpux, this
206	should be +z.  It is up to the makefile to use it.
207
208ccdlflags (dlsrc.U):
209	This variable contains any special flags that might need to be
210	passed to cc to link with a shared library for dynamic loading.
211	It is up to the makefile to use it.  For sunos 4.1, it should
212	be empty.
213
214ccflags (ccflags.U):
215	This variable contains any additional C compiler flags desired by
216	the user.  It is up to the Makefile to use this.
217
218ccflags_uselargefiles (uselfs.U):
219	This variable contains the compiler flags needed by large file builds
220	and added to ccflags by hints files.
221
222ccname (Checkcc.U):
223	This can set either by hints files or by Configure.  If using
224	gcc, this is gcc, and if not, usually equal to cc, unimpressive, no?
225	Some platforms, however, make good use of this by storing the
226	flavor of the C compiler being used here.  For example if using
227	the Sun WorkShop suite, ccname will be 'workshop'.
228
229ccsymbols (Cppsym.U):
230	The variable contains the symbols defined by the C compiler alone.
231	The symbols defined by cpp or by cc when it calls cpp are not in
232	this list, see cppsymbols and cppccsymbols.
233	The list is a space-separated list of symbol=value tokens.
234
235ccversion (Checkcc.U):
236	This can set either by hints files or by Configure.  If using
237	a (non-gcc) vendor cc, this variable may contain a version for
238	the compiler.
239
240cf_by (cf_who.U):
241	Login name of the person who ran the Configure script and answered the
242	questions. This is used to tag both config.sh and config_h.SH.
243
244cf_email (cf_email.U):
245	Electronic mail address of the person who ran Configure. This can be
246	used by units that require the user's e-mail, like MailList.U.
247
248cf_time (cf_who.U):
249	Holds the output of the "date" command when the configuration file was
250	produced. This is used to tag both config.sh and config_h.SH.
251
252charbits (charsize.U):
253	This variable contains the value of the CHARBITS symbol, which
254	indicates to the C program how many bits there are in a character.
255
256charsize (charsize.U):
257	This variable contains the value of the CHARSIZE symbol, which
258	indicates to the C program how many bytes there are in a character.
259
260chgrp (Loc.U):
261	This variable is defined but not used by Configure.
262	The value is the empty string and is not useful.
263
264chmod (Loc.U):
265	This variable is used internally by Configure to determine the
266	full pathname (if any) of the chmod program.  After Configure runs,
267	the value is reset to a plain "chmod" and is not useful.
268
269chown (Loc.U):
270	This variable is defined but not used by Configure.
271	The value is the empty string and is not useful.
272
273clocktype (d_times.U):
274	This variable holds the type returned by times(). It can be long,
275	or clock_t on BSD sites (in which case <sys/types.h> should be
276	included).
277
278comm (Loc.U):
279	This variable is used internally by Configure to determine the
280	full pathname (if any) of the comm program.  After Configure runs,
281	the value is reset to a plain "comm" and is not useful.
282
283compress (Loc.U):
284	This variable is defined but not used by Configure.
285	The value is the empty string and is not useful.
286
287config_arg0 (Options.U):
288	This variable contains the string used to invoke the Configure
289	command, as reported by the shell in the $0 variable.
290
291config_argc (Options.U):
292	This variable contains the number of command-line arguments
293	passed to Configure, as reported by the shell in the $# variable.
294	The individual arguments are stored as variables config_arg1,
295	config_arg2, etc.
296
297config_args (Options.U):
298	This variable contains a single string giving the command-line
299	arguments passed to Configure.	Spaces within arguments,
300	quotes, and escaped characters are not correctly preserved.
301	To reconstruct the command line, you must assemble the individual
302	command line pieces, given in config_arg[0-9]*.
303
304contains (contains.U):
305	This variable holds the command to do a grep with a proper return
306	status.  On most sane systems it is simply "grep".  On insane systems
307	it is a grep followed by a cat followed by a test.  This variable
308	is primarily for the use of other Configure units.
309
310cp (Loc.U):
311	This variable is used internally by Configure to determine the
312	full pathname (if any) of the cp program.  After Configure runs,
313	the value is reset to a plain "cp" and is not useful.
314
315cpio (Loc.U):
316	This variable is defined but not used by Configure.
317	The value is the empty string and is not useful.
318
319cpp (Loc.U):
320	This variable is used internally by Configure to determine the
321	full pathname (if any) of the cpp program.  After Configure runs,
322	the value is reset to a plain "cpp" and is not useful.
323
324cpp_stuff (cpp_stuff.U):
325	This variable contains an identification of the concatenation mechanism
326	used by the C preprocessor.
327
328cppccsymbols (Cppsym.U):
329	The variable contains the symbols defined by the C compiler
330	when it calls cpp.  The symbols defined by the cc alone or cpp
331	alone are not in this list, see ccsymbols and cppsymbols.
332	The list is a space-separated list of symbol=value tokens.
333
334cppflags (ccflags.U):
335	This variable holds the flags that will be passed to the C pre-
336	processor. It is up to the Makefile to use it.
337
338cpplast (cppstdin.U):
339	This variable has the same functionality as cppminus, only it applies
340	to cpprun and not cppstdin.
341
342cppminus (cppstdin.U):
343	This variable contains the second part of the string which will invoke
344	the C preprocessor on the standard input and produce to standard
345	output.  This variable will have the value "-" if cppstdin needs
346	a minus to specify standard input, otherwise the value is "".
347
348cpprun (cppstdin.U):
349	This variable contains the command which will invoke a C preprocessor
350	on standard input and put the output to stdout. It is guaranteed not
351	to be a wrapper and may be a null string if no preprocessor can be
352	made directly available. This preprocessor might be different from the
353	one used by the C compiler. Don't forget to append cpplast after the
354	preprocessor options.
355
356cppstdin (cppstdin.U):
357	This variable contains the command which will invoke the C
358	preprocessor on standard input and put the output to stdout.
359	It is primarily used by other Configure units that ask about
360	preprocessor symbols.
361
362cppsymbols (Cppsym.U):
363	The variable contains the symbols defined by the C preprocessor
364	alone.  The symbols defined by cc or by cc when it calls cpp are
365	not in this list, see ccsymbols and cppccsymbols.
366	The list is a space-separated list of symbol=value tokens.
367
368crypt_r_proto (d_crypt_r.U):
369	This variable encodes the prototype of crypt_r.
370	It is zero if d_crypt_r is undef, and one of the
371	REENTRANT_PROTO_T_ABC macros of reentr.h if d_crypt_r
372	is defined.
373
374cryptlib (d_crypt.U):
375	This variable holds -lcrypt or the path to a libcrypt.a archive if
376	the crypt() function is not defined in the standard C library. It is
377	up to the Makefile to use this.
378
379csh (Loc.U):
380	This variable is used internally by Configure to determine the
381	full pathname (if any) of the csh program.  After Configure runs,
382	the value is reset to a plain "csh" and is not useful.
383
384ctermid_r_proto (d_ctermid_r.U):
385	This variable encodes the prototype of ctermid_r.
386	It is zero if d_ctermid_r is undef, and one of the
387	REENTRANT_PROTO_T_ABC macros of reentr.h if d_ctermid_r
388	is defined.
389
390ctime_r_proto (d_ctime_r.U):
391	This variable encodes the prototype of ctime_r.
392	It is zero if d_ctime_r is undef, and one of the
393	REENTRANT_PROTO_T_ABC macros of reentr.h if d_ctime_r
394	is defined.
395
396d__fwalk (d__fwalk.U):
397	This variable conditionally defines HAS__FWALK if _fwalk() is
398	available to apply a function to all the file handles.
399
400d_access (d_access.U):
401	This variable conditionally defines HAS_ACCESS if the access() system
402	call is available to check for access permissions using real IDs.
403
404d_accessx (d_accessx.U):
405	This variable conditionally defines the HAS_ACCESSX symbol, which
406	indicates to the C program that the accessx() routine is available.
407
408d_aintl (d_aintl.U):
409	This variable conditionally defines the HAS_AINTL symbol, which
410	indicates to the C program that the aintl() routine is available.
411	If copysignl is also present we can emulate modfl.
412
413d_alarm (d_alarm.U):
414	This variable conditionally defines the HAS_ALARM symbol, which
415	indicates to the C program that the alarm() routine is available.
416
417d_archlib (archlib.U):
418	This variable conditionally defines ARCHLIB to hold the pathname
419	of architecture-dependent library files for $package.  If
420	$archlib is the same as $privlib, then this is set to undef.
421
422d_asctime64 (d_timefuncs64.U):
423	This variable conditionally defines the HAS_ASCTIME64 symbol, which
424	indicates to the C program that the asctime64 () routine is available.
425
426d_asctime_r (d_asctime_r.U):
427	This variable conditionally defines the HAS_ASCTIME_R symbol,
428	which indicates to the C program that the asctime_r()
429	routine is available.
430
431d_atolf (atolf.U):
432	This variable conditionally defines the HAS_ATOLF symbol, which
433	indicates to the C program that the atolf() routine is available.
434
435d_atoll (atoll.U):
436	This variable conditionally defines the HAS_ATOLL symbol, which
437	indicates to the C program that the atoll() routine is available.
438
439d_attribute_deprecated (d_attribut.U):
440	This variable conditionally defines HASATTRIBUTE_DEPRECATED, which
441	indicates that GCC can handle the attribute for marking deprecated
442	APIs
443
444d_attribute_format (d_attribut.U):
445	This variable conditionally defines HASATTRIBUTE_FORMAT, which
446	indicates the C compiler can check for printf-like formats.
447
448d_attribute_malloc (d_attribut.U):
449	This variable conditionally defines HASATTRIBUTE_MALLOC, which
450	indicates the C compiler can understand functions as having
451	malloc-like semantics.
452
453d_attribute_nonnull (d_attribut.U):
454	This variable conditionally defines HASATTRIBUTE_NONNULL, which
455	indicates that the C compiler can know that certain arguments
456	must not be NULL, and will check accordingly at compile time.
457
458d_attribute_noreturn (d_attribut.U):
459	This variable conditionally defines HASATTRIBUTE_NORETURN, which
460	indicates that the C compiler can know that certain functions
461	are guaranteed never to return.
462
463d_attribute_pure (d_attribut.U):
464	This variable conditionally defines HASATTRIBUTE_PURE, which
465	indicates that the C compiler can know that certain functions
466	are "pure" functions, meaning that they have no side effects, and
467	only rely on function input and/or global data for their results.
468
469d_attribute_unused (d_attribut.U):
470	This variable conditionally defines HASATTRIBUTE_UNUSED, which
471	indicates that the C compiler can know that certain variables
472	and arguments may not always be used, and to not throw warnings
473	if they don't get used.
474
475d_attribute_warn_unused_result (d_attribut.U):
476	This variable conditionally defines
477	HASATTRIBUTE_WARN_UNUSED_RESULT, which indicates that the C
478	compiler can know that certain functions have a return values
479	that must not be ignored, such as malloc() or open().
480
481d_bcmp (d_bcmp.U):
482	This variable conditionally defines the HAS_BCMP symbol if
483	the bcmp() routine is available to compare strings.
484
485d_bcopy (d_bcopy.U):
486	This variable conditionally defines the HAS_BCOPY symbol if
487	the bcopy() routine is available to copy strings.
488
489d_bsd (Guess.U):
490	This symbol conditionally defines the symbol BSD when running on a
491	BSD system.
492
493d_bsdgetpgrp (d_getpgrp.U):
494	This variable conditionally defines USE_BSD_GETPGRP if
495	getpgrp needs one arguments whereas USG one needs none.
496
497d_bsdsetpgrp (d_setpgrp.U):
498	This variable conditionally defines USE_BSD_SETPGRP if
499	setpgrp needs two arguments whereas USG one needs none.
500	See also d_setpgid for a POSIX interface.
501
502d_builtin_choose_expr (d_builtin.U):
503	This conditionally defines HAS_BUILTIN_CHOOSE_EXPR, which
504	indicates that the compiler supports __builtin_choose_expr(x,y,z).
505	This built-in function is analogous to the "x?y:z" operator in C,
506	except that the expression returned has its type unaltered by
507	promotion rules. Also, the built-in function does not evaluate
508	the expression that was not chosen.
509
510d_builtin_expect (d_builtin.U):
511	This conditionally defines HAS_BUILTIN_EXPECT, which indicates
512	that the compiler supports __builtin_expect(exp,c).  You may use
513	__builtin_expect to provide the compiler with branch prediction
514	information.
515
516d_bzero (d_bzero.U):
517	This variable conditionally defines the HAS_BZERO symbol if
518	the bzero() routine is available to set memory to 0.
519
520d_c99_variadic_macros (d_c99_variadic.U):
521	This variable conditionally defines the HAS_C99_VARIADIC_MACROS
522	symbol, which indicates to the C program that C99 variadic macros
523	are available.
524
525d_casti32 (d_casti32.U):
526	This variable conditionally defines CASTI32, which indicates
527	whether the C compiler can cast large floats to 32-bit ints.
528
529d_castneg (d_castneg.U):
530	This variable conditionally defines CASTNEG, which indicates
531	whether the C compiler can cast negative float to unsigned.
532
533d_charvspr (d_vprintf.U):
534	This variable conditionally defines CHARVSPRINTF if this system
535	has vsprintf returning type (char*).  The trend seems to be to
536	declare it as "int vsprintf()".
537
538d_chown (d_chown.U):
539	This variable conditionally defines the HAS_CHOWN symbol, which
540	indicates to the C program that the chown() routine is available.
541
542d_chroot (d_chroot.U):
543	This variable conditionally defines the HAS_CHROOT symbol, which
544	indicates to the C program that the chroot() routine is available.
545
546d_chsize (d_chsize.U):
547	This variable conditionally defines the CHSIZE symbol, which
548	indicates to the C program that the chsize() routine is available
549	to truncate files.  You might need a -lx to get this routine.
550
551d_class (d_class.U):
552	This variable conditionally defines the HAS_CLASS symbol, which
553	indicates to the C program that the class() routine is available.
554
555d_clearenv (d_clearenv.U):
556	This variable conditionally defines the HAS_CLEARENV symbol, which
557	indicates to the C program that the clearenv () routine is available.
558
559d_closedir (d_closedir.U):
560	This variable conditionally defines HAS_CLOSEDIR if closedir() is
561	available.
562
563d_cmsghdr_s (d_cmsghdr_s.U):
564	This variable conditionally defines the HAS_STRUCT_CMSGHDR symbol,
565	which indicates that the struct cmsghdr is supported.
566
567d_const (d_const.U):
568	This variable conditionally defines the HASCONST symbol, which
569	indicates to the C program that this C compiler knows about the
570	const type.
571
572d_copysignl (d_copysignl.U):
573	This variable conditionally defines the HAS_COPYSIGNL symbol, which
574	indicates to the C program that the copysignl() routine is available.
575	If aintl is also present we can emulate modfl.
576
577d_cplusplus (d_cplusplus.U):
578	This variable conditionally defines the USE_CPLUSPLUS symbol, which
579	indicates that a C++ compiler was used to compiled Perl and will be
580	used to compile extensions.
581
582d_crypt (d_crypt.U):
583	This variable conditionally defines the CRYPT symbol, which
584	indicates to the C program that the crypt() routine is available
585	to encrypt passwords and the like.
586
587d_crypt_r (d_crypt_r.U):
588	This variable conditionally defines the HAS_CRYPT_R symbol,
589	which indicates to the C program that the crypt_r()
590	routine is available.
591
592d_csh (d_csh.U):
593	This variable conditionally defines the CSH symbol, which
594	indicates to the C program that the C-shell exists.
595
596d_ctermid (d_ctermid.U):
597	This variable conditionally defines CTERMID if ctermid() is
598	available to generate filename for terminal.
599
600d_ctermid_r (d_ctermid_r.U):
601	This variable conditionally defines the HAS_CTERMID_R symbol,
602	which indicates to the C program that the ctermid_r()
603	routine is available.
604
605d_ctime64 (d_timefuncs64.U):
606	This variable conditionally defines the HAS_CTIME64 symbol, which
607	indicates to the C program that the ctime64 () routine is available.
608
609d_ctime_r (d_ctime_r.U):
610	This variable conditionally defines the HAS_CTIME_R symbol,
611	which indicates to the C program that the ctime_r()
612	routine is available.
613
614d_cuserid (d_cuserid.U):
615	This variable conditionally defines the HAS_CUSERID symbol, which
616	indicates to the C program that the cuserid() routine is available
617	to get character login names.
618
619d_dbl_dig (d_dbl_dig.U):
620	This variable conditionally defines d_dbl_dig if this system's
621	header files provide DBL_DIG, which is the number of significant
622	digits in a double precision number.
623
624d_dbminitproto (d_dbminitproto.U):
625	This variable conditionally defines the HAS_DBMINIT_PROTO symbol,
626	which indicates to the C program that the system provides
627	a prototype for the dbminit() function.  Otherwise, it is
628	up to the program to supply one.
629
630d_difftime (d_difftime.U):
631	This variable conditionally defines the HAS_DIFFTIME symbol, which
632	indicates to the C program that the difftime() routine is available.
633
634d_difftime64 (d_timefuncs64.U):
635	This variable conditionally defines the HAS_DIFFTIME64 symbol, which
636	indicates to the C program that the difftime64 () routine is available.
637
638d_dir_dd_fd (d_dir_dd_fd.U):
639	This variable conditionally defines the HAS_DIR_DD_FD symbol, which
640	indicates that the DIR directory stream type contains a member
641	variable called dd_fd.
642
643d_dirfd (d_dirfd.U):
644	This variable conditionally defines the HAS_DIRFD constant,
645	which indicates to the C program that dirfd() is available
646	to return the file descriptor of a directory stream.
647
648d_dirnamlen (i_dirent.U):
649	This variable conditionally defines DIRNAMLEN, which indicates
650	to the C program that the length of directory entry names is
651	provided by a d_namelen field.
652
653d_dlerror (d_dlerror.U):
654	This variable conditionally defines the HAS_DLERROR symbol, which
655	indicates to the C program that the dlerror() routine is available.
656
657d_dlopen (d_dlopen.U):
658	This variable conditionally defines the HAS_DLOPEN symbol, which
659	indicates to the C program that the dlopen() routine is available.
660
661d_dlsymun (d_dlsymun.U):
662	This variable conditionally defines DLSYM_NEEDS_UNDERSCORE, which
663	indicates that we need to prepend an underscore to the symbol
664	name before calling dlsym().
665
666d_dosuid (d_dosuid.U):
667	This variable conditionally defines the symbol DOSUID, which
668	tells the C program that it should insert setuid emulation code
669	on hosts which have setuid #! scripts disabled.
670
671d_drand48_r (d_drand48_r.U):
672	This variable conditionally defines the HAS_DRAND48_R symbol,
673	which indicates to the C program that the drand48_r()
674	routine is available.
675
676d_drand48proto (d_drand48proto.U):
677	This variable conditionally defines the HAS_DRAND48_PROTO symbol,
678	which indicates to the C program that the system provides
679	a prototype for the drand48() function.  Otherwise, it is
680	up to the program to supply one.
681
682d_dup2 (d_dup2.U):
683	This variable conditionally defines HAS_DUP2 if dup2() is
684	available to duplicate file descriptors.
685
686d_eaccess (d_eaccess.U):
687	This variable conditionally defines the HAS_EACCESS symbol, which
688	indicates to the C program that the eaccess() routine is available.
689
690d_endgrent (d_endgrent.U):
691	This variable conditionally defines the HAS_ENDGRENT symbol, which
692	indicates to the C program that the endgrent() routine is available
693	for sequential access of the group database.
694
695d_endgrent_r (d_endgrent_r.U):
696	This variable conditionally defines the HAS_ENDGRENT_R symbol,
697	which indicates to the C program that the endgrent_r()
698	routine is available.
699
700d_endhent (d_endhent.U):
701	This variable conditionally defines HAS_ENDHOSTENT if endhostent() is
702	available to close whatever was being used for host queries.
703
704d_endhostent_r (d_endhostent_r.U):
705	This variable conditionally defines the HAS_ENDHOSTENT_R symbol,
706	which indicates to the C program that the endhostent_r()
707	routine is available.
708
709d_endnent (d_endnent.U):
710	This variable conditionally defines HAS_ENDNETENT if endnetent() is
711	available to close whatever was being used for network queries.
712
713d_endnetent_r (d_endnetent_r.U):
714	This variable conditionally defines the HAS_ENDNETENT_R symbol,
715	which indicates to the C program that the endnetent_r()
716	routine is available.
717
718d_endpent (d_endpent.U):
719	This variable conditionally defines HAS_ENDPROTOENT if endprotoent() is
720	available to close whatever was being used for protocol queries.
721
722d_endprotoent_r (d_endprotoent_r.U):
723	This variable conditionally defines the HAS_ENDPROTOENT_R symbol,
724	which indicates to the C program that the endprotoent_r()
725	routine is available.
726
727d_endpwent (d_endpwent.U):
728	This variable conditionally defines the HAS_ENDPWENT symbol, which
729	indicates to the C program that the endpwent() routine is available
730	for sequential access of the passwd database.
731
732d_endpwent_r (d_endpwent_r.U):
733	This variable conditionally defines the HAS_ENDPWENT_R symbol,
734	which indicates to the C program that the endpwent_r()
735	routine is available.
736
737d_endsent (d_endsent.U):
738	This variable conditionally defines HAS_ENDSERVENT if endservent() is
739	available to close whatever was being used for service queries.
740
741d_endservent_r (d_endservent_r.U):
742	This variable conditionally defines the HAS_ENDSERVENT_R symbol,
743	which indicates to the C program that the endservent_r()
744	routine is available.
745
746d_eofnblk (nblock_io.U):
747	This variable conditionally defines EOF_NONBLOCK if EOF can be seen
748	when reading from a non-blocking I/O source.
749
750d_eunice (Guess.U):
751	This variable conditionally defines the symbols EUNICE and VAX, which
752	alerts the C program that it must deal with idiosyncrasies of VMS.
753
754d_faststdio (d_faststdio.U):
755	This variable conditionally defines the HAS_FAST_STDIO symbol,
756	which indicates to the C program that the "fast stdio" is available
757	to manipulate the stdio buffers directly.
758
759d_fchdir (d_fchdir.U):
760	This variable conditionally defines the HAS_FCHDIR symbol, which
761	indicates to the C program that the fchdir() routine is available.
762
763d_fchmod (d_fchmod.U):
764	This variable conditionally defines the HAS_FCHMOD symbol, which
765	indicates to the C program that the fchmod() routine is available
766	to change mode of opened files.
767
768d_fchown (d_fchown.U):
769	This variable conditionally defines the HAS_FCHOWN symbol, which
770	indicates to the C program that the fchown() routine is available
771	to change ownership of opened files.
772
773d_fcntl (d_fcntl.U):
774	This variable conditionally defines the HAS_FCNTL symbol, and indicates
775	whether the fcntl() function exists
776
777d_fcntl_can_lock (d_fcntl_can_lock.U):
778	This variable conditionally defines the FCNTL_CAN_LOCK symbol
779	and indicates whether file locking with fcntl() works.
780
781d_fd_macros (d_fd_set.U):
782	This variable contains the eventual value of the HAS_FD_MACROS symbol,
783	which indicates if your C compiler knows about the macros which
784	manipulate an fd_set.
785
786d_fd_set (d_fd_set.U):
787	This variable contains the eventual value of the HAS_FD_SET symbol,
788	which indicates if your C compiler knows about the fd_set typedef.
789
790d_fds_bits (d_fd_set.U):
791	This variable contains the eventual value of the HAS_FDS_BITS symbol,
792	which indicates if your fd_set typedef contains the fds_bits member.
793	If you have an fd_set typedef, but the dweebs who installed it did
794	a half-fast job and neglected to provide the macros to manipulate
795	an fd_set, HAS_FDS_BITS will let us know how to fix the gaffe.
796
797d_fgetpos (d_fgetpos.U):
798	This variable conditionally defines HAS_FGETPOS if fgetpos() is
799	available to get the file position indicator.
800
801d_finite (d_finite.U):
802	This variable conditionally defines the HAS_FINITE symbol, which
803	indicates to the C program that the finite() routine is available.
804
805d_finitel (d_finitel.U):
806	This variable conditionally defines the HAS_FINITEL symbol, which
807	indicates to the C program that the finitel() routine is available.
808
809d_flexfnam (d_flexfnam.U):
810	This variable conditionally defines the FLEXFILENAMES symbol, which
811	indicates that the system supports filenames longer than 14 characters.
812
813d_flock (d_flock.U):
814	This variable conditionally defines HAS_FLOCK if flock() is
815	available to do file locking.
816
817d_flockproto (d_flockproto.U):
818	This variable conditionally defines the HAS_FLOCK_PROTO symbol,
819	which indicates to the C program that the system provides
820	a prototype for the flock() function.  Otherwise, it is
821	up to the program to supply one.
822
823d_fork (d_fork.U):
824	This variable conditionally defines the HAS_FORK symbol, which
825	indicates to the C program that the fork() routine is available.
826
827d_fp_class (d_fp_class.U):
828	This variable conditionally defines the HAS_FP_CLASS symbol, which
829	indicates to the C program that the fp_class() routine is available.
830
831d_fpathconf (d_pathconf.U):
832	This variable conditionally defines the HAS_FPATHCONF symbol, which
833	indicates to the C program that the pathconf() routine is available
834	to determine file-system related limits and options associated
835	with a given open file descriptor.
836
837d_fpclass (d_fpclass.U):
838	This variable conditionally defines the HAS_FPCLASS symbol, which
839	indicates to the C program that the fpclass() routine is available.
840
841d_fpclassify (d_fpclassify.U):
842	This variable conditionally defines the HAS_FPCLASSIFY symbol, which
843	indicates to the C program that the fpclassify() routine is available.
844
845d_fpclassl (d_fpclassl.U):
846	This variable conditionally defines the HAS_FPCLASSL symbol, which
847	indicates to the C program that the fpclassl() routine is available.
848
849d_fpos64_t (d_fpos64_t.U):
850	This symbol will be defined if the C compiler supports fpos64_t.
851
852d_frexpl (d_frexpl.U):
853	This variable conditionally defines the HAS_FREXPL symbol, which
854	indicates to the C program that the frexpl() routine is available.
855
856d_fs_data_s (d_fs_data_s.U):
857	This variable conditionally defines the HAS_STRUCT_FS_DATA symbol,
858	which indicates that the struct fs_data is supported.
859
860d_fseeko (d_fseeko.U):
861	This variable conditionally defines the HAS_FSEEKO symbol, which
862	indicates to the C program that the fseeko() routine is available.
863
864d_fsetpos (d_fsetpos.U):
865	This variable conditionally defines HAS_FSETPOS if fsetpos() is
866	available to set the file position indicator.
867
868d_fstatfs (d_fstatfs.U):
869	This variable conditionally defines the HAS_FSTATFS symbol, which
870	indicates to the C program that the fstatfs() routine is available.
871
872d_fstatvfs (d_statvfs.U):
873	This variable conditionally defines the HAS_FSTATVFS symbol, which
874	indicates to the C program that the fstatvfs() routine is available.
875
876d_fsync (d_fsync.U):
877	This variable conditionally defines the HAS_FSYNC symbol, which
878	indicates to the C program that the fsync() routine is available.
879
880d_ftello (d_ftello.U):
881	This variable conditionally defines the HAS_FTELLO symbol, which
882	indicates to the C program that the ftello() routine is available.
883
884d_ftime (d_ftime.U):
885	This variable conditionally defines the HAS_FTIME symbol, which indicates
886	that the ftime() routine exists.  The ftime() routine is basically
887	a sub-second accuracy clock.
888
889d_futimes (d_futimes.U):
890	This variable conditionally defines the HAS_FUTIMES symbol, which
891	indicates to the C program that the futimes() routine is available.
892
893d_Gconvert (d_gconvert.U):
894	This variable holds what Gconvert is defined as to convert
895	floating point numbers into strings.  By default, Configure
896	sets this macro to use the first of gconvert, gcvt, or sprintf
897	that pass sprintf-%g-like behaviour tests.  If perl is using
898	long doubles, the macro uses the first of the following
899	functions that pass Configure's tests: qgcvt, sprintf (if
900	Configure knows how to make sprintf format long doubles--see
901	sPRIgldbl), gconvert, gcvt, and sprintf (casting to double).
902	The gconvert_preference and gconvert_ld_preference variables
903	can be used to alter Configure's preferences, for doubles and
904	long doubles, respectively.  If present, they contain a
905	space-separated list of one or more of the above function
906	names in the order they should be tried.
907
908	d_Gconvert may be set to override Configure with a platform-
909	specific function.  If this function expects a double, a
910	different value may need to be set by the uselongdouble.cbu
911	call-back unit so that long doubles can be formatted without
912	loss of precision.
913
914d_gdbm_ndbm_h_uses_prototypes (i_ndbm.U):
915	This variable conditionally defines the NDBM_H_USES_PROTOTYPES symbol,
916	which indicates that the gdbm-ndbm.h include file uses real ANSI C
917	prototypes instead of K&R style function declarations. K&R style
918	declarations are unsupported in C++, so the include file requires
919	special handling when using a C++ compiler and this variable is
920	undefined. Consult the different d_*ndbm_h_uses_prototypes variables
921	to get the same information for alternative ndbm.h include files.
922
923d_gdbmndbm_h_uses_prototypes (i_ndbm.U):
924	This variable conditionally defines the NDBM_H_USES_PROTOTYPES symbol,
925	which indicates that the gdbm/ndbm.h include file uses real ANSI C
926	prototypes instead of K&R style function declarations. K&R style
927	declarations are unsupported in C++, so the include file requires
928	special handling when using a C++ compiler and this variable is
929	undefined. Consult the different d_*ndbm_h_uses_prototypes variables
930	to get the same information for alternative ndbm.h include files.
931
932d_getaddrinfo (d_getaddrinfo.U):
933	This variable conditionally defines the HAS_GETADDRINFO symbol,
934	which indicates to the C program that the getaddrinfo() function
935	is available.
936
937d_getcwd (d_getcwd.U):
938	This variable conditionally defines the HAS_GETCWD symbol, which
939	indicates to the C program that the getcwd() routine is available
940	to get the current working directory.
941
942d_getespwnam (d_getespwnam.U):
943	This variable conditionally defines HAS_GETESPWNAM if getespwnam() is
944	available to retrieve enhanced (shadow) password entries by name.
945
946d_getfsstat (d_getfsstat.U):
947	This variable conditionally defines the HAS_GETFSSTAT symbol, which
948	indicates to the C program that the getfsstat() routine is available.
949
950d_getgrent (d_getgrent.U):
951	This variable conditionally defines the HAS_GETGRENT symbol, which
952	indicates to the C program that the getgrent() routine is available
953	for sequential access of the group database.
954
955d_getgrent_r (d_getgrent_r.U):
956	This variable conditionally defines the HAS_GETGRENT_R symbol,
957	which indicates to the C program that the getgrent_r()
958	routine is available.
959
960d_getgrgid_r (d_getgrgid_r.U):
961	This variable conditionally defines the HAS_GETGRGID_R symbol,
962	which indicates to the C program that the getgrgid_r()
963	routine is available.
964
965d_getgrnam_r (d_getgrnam_r.U):
966	This variable conditionally defines the HAS_GETGRNAM_R symbol,
967	which indicates to the C program that the getgrnam_r()
968	routine is available.
969
970d_getgrps (d_getgrps.U):
971	This variable conditionally defines the HAS_GETGROUPS symbol, which
972	indicates to the C program that the getgroups() routine is available
973	to get the list of process groups.
974
975d_gethbyaddr (d_gethbyad.U):
976	This variable conditionally defines the HAS_GETHOSTBYADDR symbol, which
977	indicates to the C program that the gethostbyaddr() routine is available
978	to look up hosts by their IP addresses.
979
980d_gethbyname (d_gethbynm.U):
981	This variable conditionally defines the HAS_GETHOSTBYNAME symbol, which
982	indicates to the C program that the gethostbyname() routine is available
983	to look up host names in some data base or other.
984
985d_gethent (d_gethent.U):
986	This variable conditionally defines HAS_GETHOSTENT if gethostent() is
987	available to look up host names in some data base or another.
988
989d_gethname (d_gethname.U):
990	This variable conditionally defines the HAS_GETHOSTNAME symbol, which
991	indicates to the C program that the gethostname() routine may be
992	used to derive the host name.
993
994d_gethostbyaddr_r (d_gethostbyaddr_r.U):
995	This variable conditionally defines the HAS_GETHOSTBYADDR_R symbol,
996	which indicates to the C program that the gethostbyaddr_r()
997	routine is available.
998
999d_gethostbyname_r (d_gethostbyname_r.U):
1000	This variable conditionally defines the HAS_GETHOSTBYNAME_R symbol,
1001	which indicates to the C program that the gethostbyname_r()
1002	routine is available.
1003
1004d_gethostent_r (d_gethostent_r.U):
1005	This variable conditionally defines the HAS_GETHOSTENT_R symbol,
1006	which indicates to the C program that the gethostent_r()
1007	routine is available.
1008
1009d_gethostprotos (d_gethostprotos.U):
1010	This variable conditionally defines the HAS_GETHOST_PROTOS symbol,
1011	which indicates to the C program that <netdb.h> supplies
1012	prototypes for the various gethost*() functions.
1013	See also netdbtype.U for probing for various netdb types.
1014
1015d_getitimer (d_getitimer.U):
1016	This variable conditionally defines the HAS_GETITIMER symbol, which
1017	indicates to the C program that the getitimer() routine is available.
1018
1019d_getlogin (d_getlogin.U):
1020	This variable conditionally defines the HAS_GETLOGIN symbol, which
1021	indicates to the C program that the getlogin() routine is available
1022	to get the login name.
1023
1024d_getlogin_r (d_getlogin_r.U):
1025	This variable conditionally defines the HAS_GETLOGIN_R symbol,
1026	which indicates to the C program that the getlogin_r()
1027	routine is available.
1028
1029d_getmnt (d_getmnt.U):
1030	This variable conditionally defines the HAS_GETMNT symbol, which
1031	indicates to the C program that the getmnt() routine is available
1032	to retrieve one or more mount info blocks by filename.
1033
1034d_getmntent (d_getmntent.U):
1035	This variable conditionally defines the HAS_GETMNTENT symbol, which
1036	indicates to the C program that the getmntent() routine is available
1037	to iterate through mounted files to get their mount info.
1038
1039d_getnameinfo (d_getnameinfo.U):
1040	This variable conditionally defines the HAS_GETNAMEINFO symbol,
1041	which indicates to the C program that the getnameinfo() function
1042	is available.
1043
1044d_getnbyaddr (d_getnbyad.U):
1045	This variable conditionally defines the HAS_GETNETBYADDR symbol, which
1046	indicates to the C program that the getnetbyaddr() routine is available
1047	to look up networks by their IP addresses.
1048
1049d_getnbyname (d_getnbynm.U):
1050	This variable conditionally defines the HAS_GETNETBYNAME symbol, which
1051	indicates to the C program that the getnetbyname() routine is available
1052	to look up networks by their names.
1053
1054d_getnent (d_getnent.U):
1055	This variable conditionally defines HAS_GETNETENT if getnetent() is
1056	available to look up network names in some data base or another.
1057
1058d_getnetbyaddr_r (d_getnetbyaddr_r.U):
1059	This variable conditionally defines the HAS_GETNETBYADDR_R symbol,
1060	which indicates to the C program that the getnetbyaddr_r()
1061	routine is available.
1062
1063d_getnetbyname_r (d_getnetbyname_r.U):
1064	This variable conditionally defines the HAS_GETNETBYNAME_R symbol,
1065	which indicates to the C program that the getnetbyname_r()
1066	routine is available.
1067
1068d_getnetent_r (d_getnetent_r.U):
1069	This variable conditionally defines the HAS_GETNETENT_R symbol,
1070	which indicates to the C program that the getnetent_r()
1071	routine is available.
1072
1073d_getnetprotos (d_getnetprotos.U):
1074	This variable conditionally defines the HAS_GETNET_PROTOS symbol,
1075	which indicates to the C program that <netdb.h> supplies
1076	prototypes for the various getnet*() functions.
1077	See also netdbtype.U for probing for various netdb types.
1078
1079d_getpagsz (d_getpagsz.U):
1080	This variable conditionally defines HAS_GETPAGESIZE if getpagesize()
1081	is available to get the system page size.
1082
1083d_getpbyname (d_getprotby.U):
1084	This variable conditionally defines the HAS_GETPROTOBYNAME
1085	symbol, which indicates to the C program that the
1086	getprotobyname() routine is available to look up protocols
1087	by their name.
1088
1089d_getpbynumber (d_getprotby.U):
1090	This variable conditionally defines the HAS_GETPROTOBYNUMBER
1091	symbol, which indicates to the C program that the
1092	getprotobynumber() routine is available to look up protocols
1093	by their number.
1094
1095d_getpent (d_getpent.U):
1096	This variable conditionally defines HAS_GETPROTOENT if getprotoent() is
1097	available to look up protocols in some data base or another.
1098
1099d_getpgid (d_getpgid.U):
1100	This variable conditionally defines the HAS_GETPGID symbol, which
1101	indicates to the C program that the getpgid(pid) function
1102	is available to get the process group id.
1103
1104d_getpgrp (d_getpgrp.U):
1105	This variable conditionally defines HAS_GETPGRP if getpgrp() is
1106	available to get the current process group.
1107
1108d_getpgrp2 (d_getpgrp2.U):
1109	This variable conditionally defines the HAS_GETPGRP2 symbol, which
1110	indicates to the C program that the getpgrp2() (as in DG/UX) routine
1111	is available to get the current process group.
1112
1113d_getppid (d_getppid.U):
1114	This variable conditionally defines the HAS_GETPPID symbol, which
1115	indicates to the C program that the getppid() routine is available
1116	to get the parent process ID.
1117
1118d_getprior (d_getprior.U):
1119	This variable conditionally defines HAS_GETPRIORITY if getpriority()
1120	is available to get a process's priority.
1121
1122d_getprotobyname_r (d_getprotobyname_r.U):
1123	This variable conditionally defines the HAS_GETPROTOBYNAME_R symbol,
1124	which indicates to the C program that the getprotobyname_r()
1125	routine is available.
1126
1127d_getprotobynumber_r (d_getprotobynumber_r.U):
1128	This variable conditionally defines the HAS_GETPROTOBYNUMBER_R symbol,
1129	which indicates to the C program that the getprotobynumber_r()
1130	routine is available.
1131
1132d_getprotoent_r (d_getprotoent_r.U):
1133	This variable conditionally defines the HAS_GETPROTOENT_R symbol,
1134	which indicates to the C program that the getprotoent_r()
1135	routine is available.
1136
1137d_getprotoprotos (d_getprotoprotos.U):
1138	This variable conditionally defines the HAS_GETPROTO_PROTOS symbol,
1139	which indicates to the C program that <netdb.h> supplies
1140	prototypes for the various getproto*() functions.
1141	See also netdbtype.U for probing for various netdb types.
1142
1143d_getprpwnam (d_getprpwnam.U):
1144	This variable conditionally defines HAS_GETPRPWNAM if getprpwnam() is
1145	available to retrieve protected (shadow) password entries by name.
1146
1147d_getpwent (d_getpwent.U):
1148	This variable conditionally defines the HAS_GETPWENT symbol, which
1149	indicates to the C program that the getpwent() routine is available
1150	for sequential access of the passwd database.
1151
1152d_getpwent_r (d_getpwent_r.U):
1153	This variable conditionally defines the HAS_GETPWENT_R symbol,
1154	which indicates to the C program that the getpwent_r()
1155	routine is available.
1156
1157d_getpwnam_r (d_getpwnam_r.U):
1158	This variable conditionally defines the HAS_GETPWNAM_R symbol,
1159	which indicates to the C program that the getpwnam_r()
1160	routine is available.
1161
1162d_getpwuid_r (d_getpwuid_r.U):
1163	This variable conditionally defines the HAS_GETPWUID_R symbol,
1164	which indicates to the C program that the getpwuid_r()
1165	routine is available.
1166
1167d_getsbyname (d_getsrvby.U):
1168	This variable conditionally defines the HAS_GETSERVBYNAME
1169	symbol, which indicates to the C program that the
1170	getservbyname() routine is available to look up services
1171	by their name.
1172
1173d_getsbyport (d_getsrvby.U):
1174	This variable conditionally defines the HAS_GETSERVBYPORT
1175	symbol, which indicates to the C program that the
1176	getservbyport() routine is available to look up services
1177	by their port.
1178
1179d_getsent (d_getsent.U):
1180	This variable conditionally defines HAS_GETSERVENT if getservent() is
1181	available to look up network services in some data base or another.
1182
1183d_getservbyname_r (d_getservbyname_r.U):
1184	This variable conditionally defines the HAS_GETSERVBYNAME_R symbol,
1185	which indicates to the C program that the getservbyname_r()
1186	routine is available.
1187
1188d_getservbyport_r (d_getservbyport_r.U):
1189	This variable conditionally defines the HAS_GETSERVBYPORT_R symbol,
1190	which indicates to the C program that the getservbyport_r()
1191	routine is available.
1192
1193d_getservent_r (d_getservent_r.U):
1194	This variable conditionally defines the HAS_GETSERVENT_R symbol,
1195	which indicates to the C program that the getservent_r()
1196	routine is available.
1197
1198d_getservprotos (d_getservprotos.U):
1199	This variable conditionally defines the HAS_GETSERV_PROTOS symbol,
1200	which indicates to the C program that <netdb.h> supplies
1201	prototypes for the various getserv*() functions.
1202	See also netdbtype.U for probing for various netdb types.
1203
1204d_getspnam (d_getspnam.U):
1205	This variable conditionally defines HAS_GETSPNAM if getspnam() is
1206	available to retrieve SysV shadow password entries by name.
1207
1208d_getspnam_r (d_getspnam_r.U):
1209	This variable conditionally defines the HAS_GETSPNAM_R symbol,
1210	which indicates to the C program that the getspnam_r()
1211	routine is available.
1212
1213d_gettimeod (d_ftime.U):
1214	This variable conditionally defines the HAS_GETTIMEOFDAY symbol, which
1215	indicates that the gettimeofday() system call exists (to obtain a
1216	sub-second accuracy clock). You should probably include <sys/resource.h>.
1217
1218d_gmtime64 (d_timefuncs64.U):
1219	This variable conditionally defines the HAS_GMTIME64 symbol, which
1220	indicates to the C program that the gmtime64 () routine is available.
1221
1222d_gmtime_r (d_gmtime_r.U):
1223	This variable conditionally defines the HAS_GMTIME_R symbol,
1224	which indicates to the C program that the gmtime_r()
1225	routine is available.
1226
1227d_gnulibc (d_gnulibc.U):
1228	Defined if we're dealing with the GNU C Library.
1229
1230d_grpasswd (i_grp.U):
1231	This variable conditionally defines GRPASSWD, which indicates
1232	that struct group in <grp.h> contains gr_passwd.
1233
1234d_hasmntopt (d_hasmntopt.U):
1235	This variable conditionally defines the HAS_HASMNTOPT symbol, which
1236	indicates to the C program that the hasmntopt() routine is available
1237	to query the mount options of file systems.
1238
1239d_htonl (d_htonl.U):
1240	This variable conditionally defines HAS_HTONL if htonl() and its
1241	friends are available to do network order byte swapping.
1242
1243d_ilogbl (d_ilogbl.U):
1244	This variable conditionally defines the HAS_ILOGBL symbol, which
1245	indicates to the C program that the ilogbl() routine is available.
1246	If scalbnl is also present we can emulate frexpl.
1247
1248d_inc_version_list (inc_version_list.U):
1249	This variable conditionally defines PERL_INC_VERSION_LIST.
1250	It is set to undef when PERL_INC_VERSION_LIST is empty.
1251
1252d_index (d_strchr.U):
1253	This variable conditionally defines HAS_INDEX if index() and
1254	rindex() are available for string searching.
1255
1256d_inetaton (d_inetaton.U):
1257	This variable conditionally defines the HAS_INET_ATON symbol, which
1258	indicates to the C program that the inet_aton() function is available
1259	to parse IP address "dotted-quad" strings.
1260
1261d_inetntop (d_inetntop.U):
1262	This variable conditionally defines the HAS_INETNTOP symbol,
1263	which indicates to the C program that the inet_ntop() function
1264	is available.
1265
1266d_inetpton (d_inetpton.U):
1267	This variable conditionally defines the HAS_INETPTON symbol,
1268	which indicates to the C program that the inet_pton() function
1269	is available.
1270
1271d_int64_t (d_int64_t.U):
1272	This symbol will be defined if the C compiler supports int64_t.
1273
1274d_ipv6_mreq (d_socket.U):
1275	This variable conditionally defines the HAS_IPV6_MREQ symbol, which
1276	indicates the availability of a struct ipv6_mreq.
1277
1278d_isascii (d_isascii.U):
1279	This variable conditionally defines the HAS_ISASCII constant,
1280	which indicates to the C program that isascii() is available.
1281
1282d_isblank (d_isblank.U):
1283	This variable conditionally defines the HAS_ISBLANK constant,
1284	which indicates to the C program that isblank() is available.
1285
1286d_isfinite (d_isfinite.U):
1287	This variable conditionally defines the HAS_ISFINITE symbol, which
1288	indicates to the C program that the isfinite() routine is available.
1289
1290d_isinf (d_isinf.U):
1291	This variable conditionally defines the HAS_ISINF symbol, which
1292	indicates to the C program that the isinf() routine is available.
1293
1294d_isnan (d_isnan.U):
1295	This variable conditionally defines the HAS_ISNAN symbol, which
1296	indicates to the C program that the isnan() routine is available.
1297
1298d_isnanl (d_isnanl.U):
1299	This variable conditionally defines the HAS_ISNANL symbol, which
1300	indicates to the C program that the isnanl() routine is available.
1301
1302d_killpg (d_killpg.U):
1303	This variable conditionally defines the HAS_KILLPG symbol, which
1304	indicates to the C program that the killpg() routine is available
1305	to kill process groups.
1306
1307d_lchown (d_lchown.U):
1308	This variable conditionally defines the HAS_LCHOWN symbol, which
1309	indicates to the C program that the lchown() routine is available
1310	to operate on a symbolic link (instead of following the link).
1311
1312d_ldbl_dig (d_ldbl_dig.U):
1313	This variable conditionally defines d_ldbl_dig if this system's
1314	header files provide LDBL_DIG, which is the number of significant
1315	digits in a long double precision number.
1316
1317d_libm_lib_version (d_libm_lib_version.U):
1318	This variable conditionally defines the LIBM_LIB_VERSION symbol,
1319	which indicates to the C program that math.h defines _LIB_VERSION
1320	being available in libm
1321
1322d_link (d_link.U):
1323	This variable conditionally defines HAS_LINK if link() is
1324	available to create hard links.
1325
1326d_localtime64 (d_timefuncs64.U):
1327	This variable conditionally defines the HAS_LOCALTIME64 symbol, which
1328	indicates to the C program that the localtime64 () routine is available.
1329
1330d_localtime_r (d_localtime_r.U):
1331	This variable conditionally defines the HAS_LOCALTIME_R symbol,
1332	which indicates to the C program that the localtime_r()
1333	routine is available.
1334
1335d_localtime_r_needs_tzset (d_localtime_r.U):
1336	This variable conditionally defines the LOCALTIME_R_NEEDS_TZSET
1337	symbol, which makes us call tzset before localtime_r()
1338
1339d_locconv (d_locconv.U):
1340	This variable conditionally defines HAS_LOCALECONV if localeconv() is
1341	available for numeric and monetary formatting conventions.
1342
1343d_lockf (d_lockf.U):
1344	This variable conditionally defines HAS_LOCKF if lockf() is
1345	available to do file locking.
1346
1347d_longdbl (d_longdbl.U):
1348	This variable conditionally defines HAS_LONG_DOUBLE if
1349	the long double type is supported.
1350
1351d_longlong (d_longlong.U):
1352	This variable conditionally defines HAS_LONG_LONG if
1353	the long long type is supported.
1354
1355d_lseekproto (d_lseekproto.U):
1356	This variable conditionally defines the HAS_LSEEK_PROTO symbol,
1357	which indicates to the C program that the system provides
1358	a prototype for the lseek() function.  Otherwise, it is
1359	up to the program to supply one.
1360
1361d_lstat (d_lstat.U):
1362	This variable conditionally defines HAS_LSTAT if lstat() is
1363	available to do file stats on symbolic links.
1364
1365d_madvise (d_madvise.U):
1366	This variable conditionally defines HAS_MADVISE if madvise() is
1367	available to map a file into memory.
1368
1369d_malloc_good_size (d_malloc_size.U):
1370	This symbol, if defined, indicates that the malloc_good_size
1371	routine is available for use.
1372
1373d_malloc_size (d_malloc_size.U):
1374	This symbol, if defined, indicates that the malloc_size
1375	routine is available for use.
1376
1377d_mblen (d_mblen.U):
1378	This variable conditionally defines the HAS_MBLEN symbol, which
1379	indicates to the C program that the mblen() routine is available
1380	to find the number of bytes in a multibye character.
1381
1382d_mbstowcs (d_mbstowcs.U):
1383	This variable conditionally defines the HAS_MBSTOWCS symbol, which
1384	indicates to the C program that the mbstowcs() routine is available
1385	to convert a multibyte string into a wide character string.
1386
1387d_mbtowc (d_mbtowc.U):
1388	This variable conditionally defines the HAS_MBTOWC symbol, which
1389	indicates to the C program that the mbtowc() routine is available
1390	to convert multibyte to a wide character.
1391
1392d_memchr (d_memchr.U):
1393	This variable conditionally defines the HAS_MEMCHR symbol, which
1394	indicates to the C program that the memchr() routine is available
1395	to locate characters within a C string.
1396
1397d_memcmp (d_memcmp.U):
1398	This variable conditionally defines the HAS_MEMCMP symbol, which
1399	indicates to the C program that the memcmp() routine is available
1400	to compare blocks of memory.
1401
1402d_memcpy (d_memcpy.U):
1403	This variable conditionally defines the HAS_MEMCPY symbol, which
1404	indicates to the C program that the memcpy() routine is available
1405	to copy blocks of memory.
1406
1407d_memmove (d_memmove.U):
1408	This variable conditionally defines the HAS_MEMMOVE symbol, which
1409	indicates to the C program that the memmove() routine is available
1410	to copy potentially overlapping blocks of memory.
1411
1412d_memset (d_memset.U):
1413	This variable conditionally defines the HAS_MEMSET symbol, which
1414	indicates to the C program that the memset() routine is available
1415	to set blocks of memory.
1416
1417d_mkdir (d_mkdir.U):
1418	This variable conditionally defines the HAS_MKDIR symbol, which
1419	indicates to the C program that the mkdir() routine is available
1420	to create directories..
1421
1422d_mkdtemp (d_mkdtemp.U):
1423	This variable conditionally defines the HAS_MKDTEMP symbol, which
1424	indicates to the C program that the mkdtemp() routine is available
1425	to exclusively create a uniquely named temporary directory.
1426
1427d_mkfifo (d_mkfifo.U):
1428	This variable conditionally defines the HAS_MKFIFO symbol, which
1429	indicates to the C program that the mkfifo() routine is available.
1430
1431d_mkstemp (d_mkstemp.U):
1432	This variable conditionally defines the HAS_MKSTEMP symbol, which
1433	indicates to the C program that the mkstemp() routine is available
1434	to exclusively create and open a uniquely named temporary file.
1435
1436d_mkstemps (d_mkstemps.U):
1437	This variable conditionally defines the HAS_MKSTEMPS symbol, which
1438	indicates to the C program that the mkstemps() routine is available
1439	to exclusively create and open a uniquely named (with a suffix)
1440	temporary file.
1441
1442d_mktime (d_mktime.U):
1443	This variable conditionally defines the HAS_MKTIME symbol, which
1444	indicates to the C program that the mktime() routine is available.
1445
1446d_mktime64 (d_timefuncs64.U):
1447	This variable conditionally defines the HAS_MKTIME64 symbol, which
1448	indicates to the C program that the mktime64 () routine is available.
1449
1450d_mmap (d_mmap.U):
1451	This variable conditionally defines HAS_MMAP if mmap() is
1452	available to map a file into memory.
1453
1454d_modfl (d_modfl.U):
1455	This variable conditionally defines the HAS_MODFL symbol, which
1456	indicates to the C program that the modfl() routine is available.
1457
1458d_modfl_pow32_bug (d_modfl.U):
1459	This variable conditionally defines the HAS_MODFL_POW32_BUG symbol,
1460	which indicates that modfl() is broken for long doubles >= pow(2, 32).
1461	For example from 4294967303.150000 one would get 4294967302.000000
1462	and 1.150000.  The bug has been seen in certain versions of glibc,
1463	release 2.2.2 is known to be okay.
1464
1465d_modflproto (d_modfl.U):
1466	This symbol, if defined, indicates that the system provides
1467	a prototype for the modfl() function.  Otherwise, it is up
1468	to the program to supply one.  C99 says it should be
1469	long double modfl(long double, long double *);
1470
1471d_mprotect (d_mprotect.U):
1472	This variable conditionally defines HAS_MPROTECT if mprotect() is
1473	available to modify the access protection of a memory mapped file.
1474
1475d_msg (d_msg.U):
1476	This variable conditionally defines the HAS_MSG symbol, which
1477	indicates that the entire msg*(2) library is present.
1478
1479d_msg_ctrunc (d_socket.U):
1480	This variable conditionally defines the HAS_MSG_CTRUNC symbol,
1481	which indicates that the MSG_CTRUNC is available.  #ifdef is
1482	not enough because it may be an enum, glibc has been known to do this.
1483
1484d_msg_dontroute (d_socket.U):
1485	This variable conditionally defines the HAS_MSG_DONTROUTE symbol,
1486	which indicates that the MSG_DONTROUTE is available.  #ifdef is
1487	not enough because it may be an enum, glibc has been known to do this.
1488
1489d_msg_oob (d_socket.U):
1490	This variable conditionally defines the HAS_MSG_OOB symbol,
1491	which indicates that the MSG_OOB is available.  #ifdef is
1492	not enough because it may be an enum, glibc has been known to do this.
1493
1494d_msg_peek (d_socket.U):
1495	This variable conditionally defines the HAS_MSG_PEEK symbol,
1496	which indicates that the MSG_PEEK is available.  #ifdef is
1497	not enough because it may be an enum, glibc has been known to do this.
1498
1499d_msg_proxy (d_socket.U):
1500	This variable conditionally defines the HAS_MSG_PROXY symbol,
1501	which indicates that the MSG_PROXY is available.  #ifdef is
1502	not enough because it may be an enum, glibc has been known to do this.
1503
1504d_msgctl (d_msgctl.U):
1505	This variable conditionally defines the HAS_MSGCTL symbol, which
1506	indicates to the C program that the msgctl() routine is available.
1507
1508d_msgget (d_msgget.U):
1509	This variable conditionally defines the HAS_MSGGET symbol, which
1510	indicates to the C program that the msgget() routine is available.
1511
1512d_msghdr_s (d_msghdr_s.U):
1513	This variable conditionally defines the HAS_STRUCT_MSGHDR symbol,
1514	which indicates that the struct msghdr is supported.
1515
1516d_msgrcv (d_msgrcv.U):
1517	This variable conditionally defines the HAS_MSGRCV symbol, which
1518	indicates to the C program that the msgrcv() routine is available.
1519
1520d_msgsnd (d_msgsnd.U):
1521	This variable conditionally defines the HAS_MSGSND symbol, which
1522	indicates to the C program that the msgsnd() routine is available.
1523
1524d_msync (d_msync.U):
1525	This variable conditionally defines HAS_MSYNC if msync() is
1526	available to synchronize a mapped file.
1527
1528d_munmap (d_munmap.U):
1529	This variable conditionally defines HAS_MUNMAP if munmap() is
1530	available to unmap a region mapped by mmap().
1531
1532d_mymalloc (mallocsrc.U):
1533	This variable conditionally defines MYMALLOC in case other parts
1534	of the source want to take special action if MYMALLOC is used.
1535	This may include different sorts of profiling or error detection.
1536
1537d_ndbm (i_ndbm.U):
1538	This variable conditionally defines the HAS_NDBM symbol, which
1539	indicates that both the ndbm.h include file and an appropriate ndbm
1540	library exist.  Consult the different i_*ndbm variables
1541	to find out the actual include location.  Sometimes, a system has the
1542	header file but not the library.  This variable will only be set if
1543	the system has both.
1544
1545d_ndbm_h_uses_prototypes (i_ndbm.U):
1546	This variable conditionally defines the NDBM_H_USES_PROTOTYPES symbol,
1547	which indicates that the ndbm.h include file uses real ANSI C
1548	prototypes instead of K&R style function declarations. K&R style
1549	declarations are unsupported in C++, so the include file requires
1550	special handling when using a C++ compiler and this variable is
1551	undefined. Consult the different d_*ndbm_h_uses_prototypes variables
1552	to get the same information for alternative ndbm.h include files.
1553
1554d_nice (d_nice.U):
1555	This variable conditionally defines the HAS_NICE symbol, which
1556	indicates to the C program that the nice() routine is available.
1557
1558d_nl_langinfo (d_nl_langinfo.U):
1559	This variable conditionally defines the HAS_NL_LANGINFO symbol, which
1560	indicates to the C program that the nl_langinfo() routine is available.
1561
1562d_nv_preserves_uv (perlxv.U):
1563	This variable indicates whether a variable of type nvtype
1564	can preserve all the bits a variable of type uvtype.
1565
1566d_nv_zero_is_allbits_zero (perlxv.U):
1567	This variable indicates whether a variable of type nvtype
1568	stores 0.0 in memory as all bits zero.
1569
1570d_off64_t (d_off64_t.U):
1571	This symbol will be defined if the C compiler supports off64_t.
1572
1573d_old_pthread_create_joinable (d_pthrattrj.U):
1574	This variable conditionally defines pthread_create_joinable.
1575	undef if pthread.h defines PTHREAD_CREATE_JOINABLE.
1576
1577d_oldpthreads (usethreads.U):
1578	This variable conditionally defines the OLD_PTHREADS_API symbol,
1579	and indicates that Perl should be built to use the old
1580	draft POSIX threads API.  This is only potentially meaningful if
1581	usethreads is set.
1582
1583d_oldsock (d_socket.U):
1584	This variable conditionally defines the OLDSOCKET symbol, which
1585	indicates that the BSD socket interface is based on 4.1c and not 4.2.
1586
1587d_open3 (d_open3.U):
1588	This variable conditionally defines the HAS_OPEN3 manifest constant,
1589	which indicates to the C program that the 3 argument version of
1590	the open(2) function is available.
1591
1592d_pathconf (d_pathconf.U):
1593	This variable conditionally defines the HAS_PATHCONF symbol, which
1594	indicates to the C program that the pathconf() routine is available
1595	to determine file-system related limits and options associated
1596	with a given filename.
1597
1598d_pause (d_pause.U):
1599	This variable conditionally defines the HAS_PAUSE symbol, which
1600	indicates to the C program that the pause() routine is available
1601	to suspend a process until a signal is received.
1602
1603d_perl_otherlibdirs (otherlibdirs.U):
1604	This variable conditionally defines PERL_OTHERLIBDIRS, which
1605	contains a colon-separated set of paths for the perl binary to
1606	include in @INC.  See also otherlibdirs.
1607
1608d_phostname (d_gethname.U):
1609	This variable conditionally defines the HAS_PHOSTNAME symbol, which
1610	contains the shell command which, when fed to popen(), may be
1611	used to derive the host name.
1612
1613d_pipe (d_pipe.U):
1614	This variable conditionally defines the HAS_PIPE symbol, which
1615	indicates to the C program that the pipe() routine is available
1616	to create an inter-process channel.
1617
1618d_poll (d_poll.U):
1619	This variable conditionally defines the HAS_POLL symbol, which
1620	indicates to the C program that the poll() routine is available
1621	to poll active file descriptors.
1622
1623d_portable (d_portable.U):
1624	This variable conditionally defines the PORTABLE symbol, which
1625	indicates to the C program that it should not assume that it is
1626	running on the machine it was compiled on.
1627
1628d_prctl (d_prctl.U):
1629	This variable conditionally defines the HAS_PRCTL symbol, which
1630	indicates to the C program that the prctl() routine is available.
1631
1632d_prctl_set_name (d_prctl.U):
1633	This variable conditionally defines the HAS_PRCTL_SET_NAME symbol,
1634	which indicates to the C program that the prctl() routine supports
1635	the PR_SET_NAME option.
1636
1637d_PRId64 (quadfio.U):
1638	This variable conditionally defines the PERL_PRId64 symbol, which
1639	indicates that stdio has a symbol to print 64-bit decimal numbers.
1640
1641d_PRIeldbl (longdblfio.U):
1642	This variable conditionally defines the PERL_PRIfldbl symbol, which
1643	indicates that stdio has a symbol to print long doubles.
1644
1645d_PRIEUldbl (longdblfio.U):
1646	This variable conditionally defines the PERL_PRIfldbl symbol, which
1647	indicates that stdio has a symbol to print long doubles.
1648	The 'U' in the name is to separate this from d_PRIeldbl so that even
1649	case-blind systems can see the difference.
1650
1651d_PRIfldbl (longdblfio.U):
1652	This variable conditionally defines the PERL_PRIfldbl symbol, which
1653	indicates that stdio has a symbol to print long doubles.
1654
1655d_PRIFUldbl (longdblfio.U):
1656	This variable conditionally defines the PERL_PRIfldbl symbol, which
1657	indicates that stdio has a symbol to print long doubles.
1658	The 'U' in the name is to separate this from d_PRIfldbl so that even
1659	case-blind systems can see the difference.
1660
1661d_PRIgldbl (longdblfio.U):
1662	This variable conditionally defines the PERL_PRIfldbl symbol, which
1663	indicates that stdio has a symbol to print long doubles.
1664
1665d_PRIGUldbl (longdblfio.U):
1666	This variable conditionally defines the PERL_PRIfldbl symbol, which
1667	indicates that stdio has a symbol to print long doubles.
1668	The 'U' in the name is to separate this from d_PRIgldbl so that even
1669	case-blind systems can see the difference.
1670
1671d_PRIi64 (quadfio.U):
1672	This variable conditionally defines the PERL_PRIi64 symbol, which
1673	indicates that stdio has a symbol to print 64-bit decimal numbers.
1674
1675d_printf_format_null (d_attribut.U):
1676	This variable conditionally defines PRINTF_FORMAT_NULL_OK, which
1677	indicates the C compiler allows printf-like formats to be null.
1678
1679d_PRIo64 (quadfio.U):
1680	This variable conditionally defines the PERL_PRIo64 symbol, which
1681	indicates that stdio has a symbol to print 64-bit octal numbers.
1682
1683d_PRIu64 (quadfio.U):
1684	This variable conditionally defines the PERL_PRIu64 symbol, which
1685	indicates that stdio has a symbol to print 64-bit unsigned decimal
1686	numbers.
1687
1688d_PRIx64 (quadfio.U):
1689	This variable conditionally defines the PERL_PRIx64 symbol, which
1690	indicates that stdio has a symbol to print 64-bit hexadecimal numbers.
1691
1692d_PRIXU64 (quadfio.U):
1693	This variable conditionally defines the PERL_PRIXU64 symbol, which
1694	indicates that stdio has a symbol to print 64-bit hExADECimAl numbers.
1695	The 'U' in the name is to separate this from d_PRIx64 so that even
1696	case-blind systems can see the difference.
1697
1698d_procselfexe (d_procselfexe.U):
1699	Defined if $procselfexe is symlink to the absolute
1700	pathname of the executing program.
1701
1702d_pseudofork (d_vfork.U):
1703	This variable conditionally defines the HAS_PSEUDOFORK symbol,
1704	which indicates that an emulation of the fork routine is available.
1705
1706d_pthread_atfork (d_pthread_atfork.U):
1707	This variable conditionally defines the HAS_PTHREAD_ATFORK symbol,
1708	which indicates to the C program that the pthread_atfork()
1709	routine is available.
1710
1711d_pthread_attr_setscope (d_pthread_attr_ss.U):
1712	This variable conditionally defines HAS_PTHREAD_ATTR_SETSCOPE if
1713	pthread_attr_setscope() is available to set the contention scope
1714	attribute of a thread attribute object.
1715
1716d_pthread_yield (d_pthread_y.U):
1717	This variable conditionally defines the HAS_PTHREAD_YIELD
1718	symbol if the pthread_yield routine is available to yield
1719	the execution of the current thread.
1720
1721d_pwage (i_pwd.U):
1722	This variable conditionally defines PWAGE, which indicates
1723	that struct passwd contains pw_age.
1724
1725d_pwchange (i_pwd.U):
1726	This variable conditionally defines PWCHANGE, which indicates
1727	that struct passwd contains pw_change.
1728
1729d_pwclass (i_pwd.U):
1730	This variable conditionally defines PWCLASS, which indicates
1731	that struct passwd contains pw_class.
1732
1733d_pwcomment (i_pwd.U):
1734	This variable conditionally defines PWCOMMENT, which indicates
1735	that struct passwd contains pw_comment.
1736
1737d_pwexpire (i_pwd.U):
1738	This variable conditionally defines PWEXPIRE, which indicates
1739	that struct passwd contains pw_expire.
1740
1741d_pwgecos (i_pwd.U):
1742	This variable conditionally defines PWGECOS, which indicates
1743	that struct passwd contains pw_gecos.
1744
1745d_pwpasswd (i_pwd.U):
1746	This variable conditionally defines PWPASSWD, which indicates
1747	that struct passwd contains pw_passwd.
1748
1749d_pwquota (i_pwd.U):
1750	This variable conditionally defines PWQUOTA, which indicates
1751	that struct passwd contains pw_quota.
1752
1753d_qgcvt (d_qgcvt.U):
1754	This variable conditionally defines the HAS_QGCVT symbol, which
1755	indicates to the C program that the qgcvt() routine is available.
1756
1757d_quad (quadtype.U):
1758	This variable, if defined, tells that there's a 64-bit integer type,
1759	quadtype.
1760
1761d_random_r (d_random_r.U):
1762	This variable conditionally defines the HAS_RANDOM_R symbol,
1763	which indicates to the C program that the random_r()
1764	routine is available.
1765
1766d_readdir (d_readdir.U):
1767	This variable conditionally defines HAS_READDIR if readdir() is
1768	available to read directory entries.
1769
1770d_readdir64_r (d_readdir64_r.U):
1771	This variable conditionally defines the HAS_READDIR64_R symbol,
1772	which indicates to the C program that the readdir64_r()
1773	routine is available.
1774
1775d_readdir_r (d_readdir_r.U):
1776	This variable conditionally defines the HAS_READDIR_R symbol,
1777	which indicates to the C program that the readdir_r()
1778	routine is available.
1779
1780d_readlink (d_readlink.U):
1781	This variable conditionally defines the HAS_READLINK symbol, which
1782	indicates to the C program that the readlink() routine is available
1783	to read the value of a symbolic link.
1784
1785d_readv (d_readv.U):
1786	This variable conditionally defines the HAS_READV symbol, which
1787	indicates to the C program that the readv() routine is available.
1788
1789d_recvmsg (d_recvmsg.U):
1790	This variable conditionally defines the HAS_RECVMSG symbol, which
1791	indicates to the C program that the recvmsg() routine is available.
1792
1793d_rename (d_rename.U):
1794	This variable conditionally defines the HAS_RENAME symbol, which
1795	indicates to the C program that the rename() routine is available
1796	to rename files.
1797
1798d_rewinddir (d_readdir.U):
1799	This variable conditionally defines HAS_REWINDDIR if rewinddir() is
1800	available.
1801
1802d_rmdir (d_rmdir.U):
1803	This variable conditionally defines HAS_RMDIR if rmdir() is
1804	available to remove directories.
1805
1806d_safebcpy (d_safebcpy.U):
1807	This variable conditionally defines the HAS_SAFE_BCOPY symbol if
1808	the bcopy() routine can do overlapping copies.  Normally, you
1809	should probably use memmove().
1810
1811d_safemcpy (d_safemcpy.U):
1812	This variable conditionally defines the HAS_SAFE_MEMCPY symbol if
1813	the memcpy() routine can do overlapping copies.
1814	For overlapping copies, memmove() should be used, if available.
1815
1816d_sanemcmp (d_sanemcmp.U):
1817	This variable conditionally defines the HAS_SANE_MEMCMP symbol if
1818	the memcpy() routine is available and can be used to compare relative
1819	magnitudes of chars with their high bits set.
1820
1821d_sbrkproto (d_sbrkproto.U):
1822	This variable conditionally defines the HAS_SBRK_PROTO symbol,
1823	which indicates to the C program that the system provides
1824	a prototype for the sbrk() function.  Otherwise, it is
1825	up to the program to supply one.
1826
1827d_scalbnl (d_scalbnl.U):
1828	This variable conditionally defines the HAS_SCALBNL symbol, which
1829	indicates to the C program that the scalbnl() routine is available.
1830	If ilogbl is also present we can emulate frexpl.
1831
1832d_sched_yield (d_pthread_y.U):
1833	This variable conditionally defines the HAS_SCHED_YIELD
1834	symbol if the sched_yield routine is available to yield
1835	the execution of the current thread.
1836
1837d_scm_rights (d_socket.U):
1838	This variable conditionally defines the HAS_SCM_RIGHTS symbol,
1839	which indicates that the SCM_RIGHTS is available.  #ifdef is
1840	not enough because it may be an enum, glibc has been known to do this.
1841
1842d_SCNfldbl (longdblfio.U):
1843	This variable conditionally defines the PERL_PRIfldbl symbol, which
1844	indicates that stdio has a symbol to scan long doubles.
1845
1846d_seekdir (d_readdir.U):
1847	This variable conditionally defines HAS_SEEKDIR if seekdir() is
1848	available.
1849
1850d_select (d_select.U):
1851	This variable conditionally defines HAS_SELECT if select() is
1852	available to select active file descriptors. A <sys/time.h>
1853	inclusion may be necessary for the timeout field.
1854
1855d_sem (d_sem.U):
1856	This variable conditionally defines the HAS_SEM symbol, which
1857	indicates that the entire sem*(2) library is present.
1858
1859d_semctl (d_semctl.U):
1860	This variable conditionally defines the HAS_SEMCTL symbol, which
1861	indicates to the C program that the semctl() routine is available.
1862
1863d_semctl_semid_ds (d_union_semun.U):
1864	This variable conditionally defines USE_SEMCTL_SEMID_DS, which
1865	indicates that struct semid_ds * is to be used for semctl IPC_STAT.
1866
1867d_semctl_semun (d_union_semun.U):
1868	This variable conditionally defines USE_SEMCTL_SEMUN, which
1869	indicates that union semun is to be used for semctl IPC_STAT.
1870
1871d_semget (d_semget.U):
1872	This variable conditionally defines the HAS_SEMGET symbol, which
1873	indicates to the C program that the semget() routine is available.
1874
1875d_semop (d_semop.U):
1876	This variable conditionally defines the HAS_SEMOP symbol, which
1877	indicates to the C program that the semop() routine is available.
1878
1879d_sendmsg (d_sendmsg.U):
1880	This variable conditionally defines the HAS_SENDMSG symbol, which
1881	indicates to the C program that the sendmsg() routine is available.
1882
1883d_setegid (d_setegid.U):
1884	This variable conditionally defines the HAS_SETEGID symbol, which
1885	indicates to the C program that the setegid() routine is available
1886	to change the effective gid of the current program.
1887
1888d_seteuid (d_seteuid.U):
1889	This variable conditionally defines the HAS_SETEUID symbol, which
1890	indicates to the C program that the seteuid() routine is available
1891	to change the effective uid of the current program.
1892
1893d_setgrent (d_setgrent.U):
1894	This variable conditionally defines the HAS_SETGRENT symbol, which
1895	indicates to the C program that the setgrent() routine is available
1896	for initializing sequential access to the group database.
1897
1898d_setgrent_r (d_setgrent_r.U):
1899	This variable conditionally defines the HAS_SETGRENT_R symbol,
1900	which indicates to the C program that the setgrent_r()
1901	routine is available.
1902
1903d_setgrps (d_setgrps.U):
1904	This variable conditionally defines the HAS_SETGROUPS symbol, which
1905	indicates to the C program that the setgroups() routine is available
1906	to set the list of process groups.
1907
1908d_sethent (d_sethent.U):
1909	This variable conditionally defines HAS_SETHOSTENT if sethostent() is
1910	available.
1911
1912d_sethostent_r (d_sethostent_r.U):
1913	This variable conditionally defines the HAS_SETHOSTENT_R symbol,
1914	which indicates to the C program that the sethostent_r()
1915	routine is available.
1916
1917d_setitimer (d_setitimer.U):
1918	This variable conditionally defines the HAS_SETITIMER symbol, which
1919	indicates to the C program that the setitimer() routine is available.
1920
1921d_setlinebuf (d_setlnbuf.U):
1922	This variable conditionally defines the HAS_SETLINEBUF symbol, which
1923	indicates to the C program that the setlinebuf() routine is available
1924	to change stderr or stdout from block-buffered or unbuffered to a
1925	line-buffered mode.
1926
1927d_setlocale (d_setlocale.U):
1928	This variable conditionally defines HAS_SETLOCALE if setlocale() is
1929	available to handle locale-specific ctype implementations.
1930
1931d_setlocale_r (d_setlocale_r.U):
1932	This variable conditionally defines the HAS_SETLOCALE_R symbol,
1933	which indicates to the C program that the setlocale_r()
1934	routine is available.
1935
1936d_setnent (d_setnent.U):
1937	This variable conditionally defines HAS_SETNETENT if setnetent() is
1938	available.
1939
1940d_setnetent_r (d_setnetent_r.U):
1941	This variable conditionally defines the HAS_SETNETENT_R symbol,
1942	which indicates to the C program that the setnetent_r()
1943	routine is available.
1944
1945d_setpent (d_setpent.U):
1946	This variable conditionally defines HAS_SETPROTOENT if setprotoent() is
1947	available.
1948
1949d_setpgid (d_setpgid.U):
1950	This variable conditionally defines the HAS_SETPGID symbol if the
1951	setpgid(pid, gpid) function is available to set process group ID.
1952
1953d_setpgrp (d_setpgrp.U):
1954	This variable conditionally defines HAS_SETPGRP if setpgrp() is
1955	available to set the current process group.
1956
1957d_setpgrp2 (d_setpgrp2.U):
1958	This variable conditionally defines the HAS_SETPGRP2 symbol, which
1959	indicates to the C program that the setpgrp2() (as in DG/UX) routine
1960	is available to set the current process group.
1961
1962d_setprior (d_setprior.U):
1963	This variable conditionally defines HAS_SETPRIORITY if setpriority()
1964	is available to set a process's priority.
1965
1966d_setproctitle (d_setproctitle.U):
1967	This variable conditionally defines the HAS_SETPROCTITLE symbol,
1968	which indicates to the C program that the setproctitle() routine
1969	is available.
1970
1971d_setprotoent_r (d_setprotoent_r.U):
1972	This variable conditionally defines the HAS_SETPROTOENT_R symbol,
1973	which indicates to the C program that the setprotoent_r()
1974	routine is available.
1975
1976d_setpwent (d_setpwent.U):
1977	This variable conditionally defines the HAS_SETPWENT symbol, which
1978	indicates to the C program that the setpwent() routine is available
1979	for initializing sequential access to the passwd database.
1980
1981d_setpwent_r (d_setpwent_r.U):
1982	This variable conditionally defines the HAS_SETPWENT_R symbol,
1983	which indicates to the C program that the setpwent_r()
1984	routine is available.
1985
1986d_setregid (d_setregid.U):
1987	This variable conditionally defines HAS_SETREGID if setregid() is
1988	available to change the real and effective gid of the current
1989	process.
1990
1991d_setresgid (d_setregid.U):
1992	This variable conditionally defines HAS_SETRESGID if setresgid() is
1993	available to change the real, effective and saved gid of the current
1994	process.
1995
1996d_setresuid (d_setreuid.U):
1997	This variable conditionally defines HAS_SETREUID if setresuid() is
1998	available to change the real, effective and saved uid of the current
1999	process.
2000
2001d_setreuid (d_setreuid.U):
2002	This variable conditionally defines HAS_SETREUID if setreuid() is
2003	available to change the real and effective uid of the current
2004	process.
2005
2006d_setrgid (d_setrgid.U):
2007	This variable conditionally defines the HAS_SETRGID symbol, which
2008	indicates to the C program that the setrgid() routine is available
2009	to change the real gid of the current program.
2010
2011d_setruid (d_setruid.U):
2012	This variable conditionally defines the HAS_SETRUID symbol, which
2013	indicates to the C program that the setruid() routine is available
2014	to change the real uid of the current program.
2015
2016d_setsent (d_setsent.U):
2017	This variable conditionally defines HAS_SETSERVENT if setservent() is
2018	available.
2019
2020d_setservent_r (d_setservent_r.U):
2021	This variable conditionally defines the HAS_SETSERVENT_R symbol,
2022	which indicates to the C program that the setservent_r()
2023	routine is available.
2024
2025d_setsid (d_setsid.U):
2026	This variable conditionally defines HAS_SETSID if setsid() is
2027	available to set the process group ID.
2028
2029d_setvbuf (d_setvbuf.U):
2030	This variable conditionally defines the HAS_SETVBUF symbol, which
2031	indicates to the C program that the setvbuf() routine is available
2032	to change buffering on an open stdio stream.
2033
2034d_sfio (d_sfio.U):
2035	This variable conditionally defines the USE_SFIO symbol,
2036	and indicates whether sfio is available (and should be used).
2037
2038d_shm (d_shm.U):
2039	This variable conditionally defines the HAS_SHM symbol, which
2040	indicates that the entire shm*(2) library is present.
2041
2042d_shmat (d_shmat.U):
2043	This variable conditionally defines the HAS_SHMAT symbol, which
2044	indicates to the C program that the shmat() routine is available.
2045
2046d_shmatprototype (d_shmat.U):
2047	This variable conditionally defines the HAS_SHMAT_PROTOTYPE
2048	symbol, which indicates that sys/shm.h has a prototype for
2049	shmat.
2050
2051d_shmctl (d_shmctl.U):
2052	This variable conditionally defines the HAS_SHMCTL symbol, which
2053	indicates to the C program that the shmctl() routine is available.
2054
2055d_shmdt (d_shmdt.U):
2056	This variable conditionally defines the HAS_SHMDT symbol, which
2057	indicates to the C program that the shmdt() routine is available.
2058
2059d_shmget (d_shmget.U):
2060	This variable conditionally defines the HAS_SHMGET symbol, which
2061	indicates to the C program that the shmget() routine is available.
2062
2063d_sigaction (d_sigaction.U):
2064	This variable conditionally defines the HAS_SIGACTION symbol, which
2065	indicates that the Vr4 sigaction() routine is available.
2066
2067d_signbit (d_signbit.U):
2068	This variable conditionally defines the HAS_SIGNBIT symbol, which
2069	indicates to the C program that the signbit() routine is available
2070	and safe to use with perl's intern NV type.
2071
2072d_sigprocmask (d_sigprocmask.U):
2073	This variable conditionally defines HAS_SIGPROCMASK
2074	if sigprocmask() is available to examine or change the signal mask
2075	of the calling process.
2076
2077d_sigsetjmp (d_sigsetjmp.U):
2078	This variable conditionally defines the HAS_SIGSETJMP symbol,
2079	which indicates that the sigsetjmp() routine is available to
2080	call setjmp() and optionally save the process's signal mask.
2081
2082d_sin6_scope_id (d_socket.U):
2083	This variable conditionally defines the HAS_SIN6_SCOPE_ID symbol, which
2084	indicates that a struct sockaddr_in6 structure has the sin6_scope_id
2085	member.
2086
2087d_sitearch (sitearch.U):
2088	This variable conditionally defines SITEARCH to hold the pathname
2089	of architecture-dependent library files for $package.  If
2090	$sitearch is the same as $archlib, then this is set to undef.
2091
2092d_snprintf (d_snprintf.U):
2093	This variable conditionally defines the HAS_SNPRINTF symbol, which
2094	indicates to the C program that the snprintf () library function
2095	is available.
2096
2097d_sockaddr_in6 (d_socket.U):
2098	This variable conditionally defines the HAS_SOCKADDR_IN6 symbol, which
2099	indicates the availability of a struct sockaddr_in6.
2100
2101d_sockaddr_sa_len (d_socket.U):
2102	This variable conditionally defines the HAS_SOCKADDR_SA_LEN symbol,
2103	which indicates that a struct sockaddr structure has the sa_len
2104	member.
2105
2106d_sockatmark (d_sockatmark.U):
2107	This variable conditionally defines the HAS_SOCKATMARK symbol, which
2108	indicates to the C program that the sockatmark() routine is available.
2109
2110d_sockatmarkproto (d_sockatmarkproto.U):
2111	This variable conditionally defines the HAS_SOCKATMARK_PROTO symbol,
2112	which indicates to the C program that the system provides
2113	a prototype for the sockatmark() function.  Otherwise, it is
2114	up to the program to supply one.
2115
2116d_socket (d_socket.U):
2117	This variable conditionally defines HAS_SOCKET, which indicates
2118	that the BSD socket interface is supported.
2119
2120d_socklen_t (d_socklen_t.U):
2121	This symbol will be defined if the C compiler supports socklen_t.
2122
2123d_sockpair (d_socket.U):
2124	This variable conditionally defines the HAS_SOCKETPAIR symbol, which
2125	indicates that the BSD socketpair() is supported.
2126
2127d_socks5_init (d_socks5_init.U):
2128	This variable conditionally defines the HAS_SOCKS5_INIT symbol, which
2129	indicates to the C program that the socks5_init() routine is available.
2130
2131d_sprintf_returns_strlen (d_sprintf_len.U):
2132	This variable defines whether sprintf returns the length of the string
2133	(as per the ANSI spec). Some C libraries retain compatibility with
2134	pre-ANSI C and return a pointer to the passed in buffer; for these
2135	this variable will be undef.
2136
2137d_sqrtl (d_sqrtl.U):
2138	This variable conditionally defines the HAS_SQRTL symbol, which
2139	indicates to the C program that the sqrtl() routine is available.
2140
2141d_srand48_r (d_srand48_r.U):
2142	This variable conditionally defines the HAS_SRAND48_R symbol,
2143	which indicates to the C program that the srand48_r()
2144	routine is available.
2145
2146d_srandom_r (d_srandom_r.U):
2147	This variable conditionally defines the HAS_SRANDOM_R symbol,
2148	which indicates to the C program that the srandom_r()
2149	routine is available.
2150
2151d_sresgproto (d_sresgproto.U):
2152	This variable conditionally defines the HAS_SETRESGID_PROTO symbol,
2153	which indicates to the C program that the system provides
2154	a prototype for the setresgid() function.  Otherwise, it is
2155	up to the program to supply one.
2156
2157d_sresuproto (d_sresuproto.U):
2158	This variable conditionally defines the HAS_SETRESUID_PROTO symbol,
2159	which indicates to the C program that the system provides
2160	a prototype for the setresuid() function.  Otherwise, it is
2161	up to the program to supply one.
2162
2163d_statblks (d_statblks.U):
2164	This variable conditionally defines USE_STAT_BLOCKS
2165	if this system has a stat structure declaring
2166	st_blksize and st_blocks.
2167
2168d_statfs_f_flags (d_statfs_f_flags.U):
2169	This variable conditionally defines the HAS_STRUCT_STATFS_F_FLAGS
2170	symbol, which indicates to struct statfs from has f_flags member.
2171	This kind of struct statfs is coming from sys/mount.h (BSD),
2172	not from sys/statfs.h (SYSV).
2173
2174d_statfs_s (d_statfs_s.U):
2175	This variable conditionally defines the HAS_STRUCT_STATFS symbol,
2176	which indicates that the struct statfs is supported.
2177
2178d_static_inline (d_static_inline.U):
2179	This variable conditionally defines the HAS_STATIC_INLINE symbol,
2180	which indicates that the C compiler supports C99-style static
2181	inline.  That is, the function can't be called from another
2182	translation unit.
2183
2184d_statvfs (d_statvfs.U):
2185	This variable conditionally defines the HAS_STATVFS symbol, which
2186	indicates to the C program that the statvfs() routine is available.
2187
2188d_stdio_cnt_lval (d_stdstdio.U):
2189	This variable conditionally defines STDIO_CNT_LVALUE if the
2190	FILE_cnt macro can be used as an lvalue.
2191
2192d_stdio_ptr_lval (d_stdstdio.U):
2193	This variable conditionally defines STDIO_PTR_LVALUE if the
2194	FILE_ptr macro can be used as an lvalue.
2195
2196d_stdio_ptr_lval_nochange_cnt (d_stdstdio.U):
2197	This symbol is defined if using the FILE_ptr macro as an lvalue
2198	to increase the pointer by n leaves File_cnt(fp) unchanged.
2199
2200d_stdio_ptr_lval_sets_cnt (d_stdstdio.U):
2201	This symbol is defined if using the FILE_ptr macro as an lvalue
2202	to increase the pointer by n has the side effect of decreasing the
2203	value of File_cnt(fp) by n.
2204
2205d_stdio_stream_array (stdio_streams.U):
2206	This variable tells whether there is an array holding
2207	the stdio streams.
2208
2209d_stdiobase (d_stdstdio.U):
2210	This variable conditionally defines USE_STDIO_BASE if this system
2211	has a FILE structure declaring a usable _base field (or equivalent)
2212	in stdio.h.
2213
2214d_stdstdio (d_stdstdio.U):
2215	This variable conditionally defines USE_STDIO_PTR if this system
2216	has a FILE structure declaring usable _ptr and _cnt fields (or
2217	equivalent) in stdio.h.
2218
2219d_strchr (d_strchr.U):
2220	This variable conditionally defines HAS_STRCHR if strchr() and
2221	strrchr() are available for string searching.
2222
2223d_strcoll (d_strcoll.U):
2224	This variable conditionally defines HAS_STRCOLL if strcoll() is
2225	available to compare strings using collating information.
2226
2227d_strctcpy (d_strctcpy.U):
2228	This variable conditionally defines the USE_STRUCT_COPY symbol, which
2229	indicates to the C program that this C compiler knows how to copy
2230	structures.
2231
2232d_strerrm (d_strerror.U):
2233	This variable holds what Strerrr is defined as to translate an error
2234	code condition into an error message string. It could be 'strerror'
2235	or a more complex macro emulating strrror with sys_errlist[], or the
2236	"unknown" string when both strerror and sys_errlist are missing.
2237
2238d_strerror (d_strerror.U):
2239	This variable conditionally defines HAS_STRERROR if strerror() is
2240	available to translate error numbers to strings.
2241
2242d_strerror_r (d_strerror_r.U):
2243	This variable conditionally defines the HAS_STRERROR_R symbol,
2244	which indicates to the C program that the strerror_r()
2245	routine is available.
2246
2247d_strftime (d_strftime.U):
2248	This variable conditionally defines the HAS_STRFTIME symbol, which
2249	indicates to the C program that the strftime() routine is available.
2250
2251d_strlcat (d_strlcat.U):
2252	This variable conditionally defines the HAS_STRLCAT symbol, which
2253	indicates to the C program that the strlcat () routine is available.
2254
2255d_strlcpy (d_strlcpy.U):
2256	This variable conditionally defines the HAS_STRLCPY symbol, which
2257	indicates to the C program that the strlcpy () routine is available.
2258
2259d_strtod (d_strtod.U):
2260	This variable conditionally defines the HAS_STRTOD symbol, which
2261	indicates to the C program that the strtod() routine is available
2262	to provide better numeric string conversion than atof().
2263
2264d_strtol (d_strtol.U):
2265	This variable conditionally defines the HAS_STRTOL symbol, which
2266	indicates to the C program that the strtol() routine is available
2267	to provide better numeric string conversion than atoi() and friends.
2268
2269d_strtold (d_strtold.U):
2270	This variable conditionally defines the HAS_STRTOLD symbol, which
2271	indicates to the C program that the strtold() routine is available.
2272
2273d_strtoll (d_strtoll.U):
2274	This variable conditionally defines the HAS_STRTOLL symbol, which
2275	indicates to the C program that the strtoll() routine is available.
2276
2277d_strtoq (d_strtoq.U):
2278	This variable conditionally defines the HAS_STRTOQ symbol, which
2279	indicates to the C program that the strtoq() routine is available.
2280
2281d_strtoul (d_strtoul.U):
2282	This variable conditionally defines the HAS_STRTOUL symbol, which
2283	indicates to the C program that the strtoul() routine is available
2284	to provide conversion of strings to unsigned long.
2285
2286d_strtoull (d_strtoull.U):
2287	This variable conditionally defines the HAS_STRTOULL symbol, which
2288	indicates to the C program that the strtoull() routine is available.
2289
2290d_strtouq (d_strtouq.U):
2291	This variable conditionally defines the HAS_STRTOUQ symbol, which
2292	indicates to the C program that the strtouq() routine is available.
2293
2294d_strxfrm (d_strxfrm.U):
2295	This variable conditionally defines HAS_STRXFRM if strxfrm() is
2296	available to transform strings.
2297
2298d_suidsafe (d_dosuid.U):
2299	This variable conditionally defines SETUID_SCRIPTS_ARE_SECURE_NOW
2300	if setuid scripts can be secure.  This test looks in /dev/fd/.
2301
2302d_symlink (d_symlink.U):
2303	This variable conditionally defines the HAS_SYMLINK symbol, which
2304	indicates to the C program that the symlink() routine is available
2305	to create symbolic links.
2306
2307d_syscall (d_syscall.U):
2308	This variable conditionally defines HAS_SYSCALL if syscall() is
2309	available call arbitrary system calls.
2310
2311d_syscallproto (d_syscallproto.U):
2312	This variable conditionally defines the HAS_SYSCALL_PROTO symbol,
2313	which indicates to the C program that the system provides
2314	a prototype for the syscall() function.  Otherwise, it is
2315	up to the program to supply one.
2316
2317d_sysconf (d_sysconf.U):
2318	This variable conditionally defines the HAS_SYSCONF symbol, which
2319	indicates to the C program that the sysconf() routine is available
2320	to determine system related limits and options.
2321
2322d_sysernlst (d_strerror.U):
2323	This variable conditionally defines HAS_SYS_ERRNOLIST if sys_errnolist[]
2324	is available to translate error numbers to the symbolic name.
2325
2326d_syserrlst (d_strerror.U):
2327	This variable conditionally defines HAS_SYS_ERRLIST if sys_errlist[] is
2328	available to translate error numbers to strings.
2329
2330d_system (d_system.U):
2331	This variable conditionally defines HAS_SYSTEM if system() is
2332	available to issue a shell command.
2333
2334d_tcgetpgrp (d_tcgtpgrp.U):
2335	This variable conditionally defines the HAS_TCGETPGRP symbol, which
2336	indicates to the C program that the tcgetpgrp() routine is available.
2337	to get foreground process group ID.
2338
2339d_tcsetpgrp (d_tcstpgrp.U):
2340	This variable conditionally defines the HAS_TCSETPGRP symbol, which
2341	indicates to the C program that the tcsetpgrp() routine is available
2342	to set foreground process group ID.
2343
2344d_telldir (d_readdir.U):
2345	This variable conditionally defines HAS_TELLDIR if telldir() is
2346	available.
2347
2348d_telldirproto (d_telldirproto.U):
2349	This variable conditionally defines the HAS_TELLDIR_PROTO symbol,
2350	which indicates to the C program that the system provides
2351	a prototype for the telldir() function.  Otherwise, it is
2352	up to the program to supply one.
2353
2354d_time (d_time.U):
2355	This variable conditionally defines the HAS_TIME symbol, which indicates
2356	that the time() routine exists.  The time() routine is normally
2357	provided on UNIX systems.
2358
2359d_timegm (d_timegm.U):
2360	This variable conditionally defines the HAS_TIMEGM symbol, which
2361	indicates to the C program that the timegm () routine is available.
2362
2363d_times (d_times.U):
2364	This variable conditionally defines the HAS_TIMES symbol, which indicates
2365	that the times() routine exists.  The times() routine is normally
2366	provided on UNIX systems. You may have to include <sys/times.h>.
2367
2368d_tm_tm_gmtoff (i_time.U):
2369	This variable conditionally defines HAS_TM_TM_GMTOFF, which indicates
2370	indicates to the C program that the struct tm has the tm_gmtoff field.
2371
2372d_tm_tm_zone (i_time.U):
2373	This variable conditionally defines HAS_TM_TM_ZONE, which indicates
2374	indicates to the C program that the struct tm has the tm_zone field.
2375
2376d_tmpnam_r (d_tmpnam_r.U):
2377	This variable conditionally defines the HAS_TMPNAM_R symbol,
2378	which indicates to the C program that the tmpnam_r()
2379	routine is available.
2380
2381d_truncate (d_truncate.U):
2382	This variable conditionally defines HAS_TRUNCATE if truncate() is
2383	available to truncate files.
2384
2385d_ttyname_r (d_ttyname_r.U):
2386	This variable conditionally defines the HAS_TTYNAME_R symbol,
2387	which indicates to the C program that the ttyname_r()
2388	routine is available.
2389
2390d_tzname (d_tzname.U):
2391	This variable conditionally defines HAS_TZNAME if tzname[] is
2392	available to access timezone names.
2393
2394d_u32align (d_u32align.U):
2395	This variable tells whether you must access character data
2396	through U32-aligned pointers.
2397
2398d_ualarm (d_ualarm.U):
2399	This variable conditionally defines the HAS_UALARM symbol, which
2400	indicates to the C program that the ualarm() routine is available.
2401
2402d_umask (d_umask.U):
2403	This variable conditionally defines the HAS_UMASK symbol, which
2404	indicates to the C program that the umask() routine is available.
2405	to set and get the value of the file creation mask.
2406
2407d_uname (d_gethname.U):
2408	This variable conditionally defines the HAS_UNAME symbol, which
2409	indicates to the C program that the uname() routine may be
2410	used to derive the host name.
2411
2412d_union_semun (d_union_semun.U):
2413	This variable conditionally defines HAS_UNION_SEMUN if the
2414	union semun is defined by including <sys/sem.h>.
2415
2416d_unordered (d_unordered.U):
2417	This variable conditionally defines the HAS_UNORDERED symbol, which
2418	indicates to the C program that the unordered() routine is available.
2419
2420d_unsetenv (d_unsetenv.U):
2421	This variable conditionally defines the HAS_UNSETENV symbol, which
2422	indicates to the C program that the unsetenv () routine is available.
2423
2424d_usleep (d_usleep.U):
2425	This variable conditionally defines HAS_USLEEP if usleep() is
2426	available to do high granularity sleeps.
2427
2428d_usleepproto (d_usleepproto.U):
2429	This variable conditionally defines the HAS_USLEEP_PROTO symbol,
2430	which indicates to the C program that the system provides
2431	a prototype for the usleep() function.  Otherwise, it is
2432	up to the program to supply one.
2433
2434d_ustat (d_ustat.U):
2435	This variable conditionally defines HAS_USTAT if ustat() is
2436	available to query file system statistics by dev_t.
2437
2438d_vendorarch (vendorarch.U):
2439	This variable conditionally defined PERL_VENDORARCH.
2440
2441d_vendorbin (vendorbin.U):
2442	This variable conditionally defines PERL_VENDORBIN.
2443
2444d_vendorlib (vendorlib.U):
2445	This variable conditionally defines PERL_VENDORLIB.
2446
2447d_vendorscript (vendorscript.U):
2448	This variable conditionally defines PERL_VENDORSCRIPT.
2449
2450d_vfork (d_vfork.U):
2451	This variable conditionally defines the HAS_VFORK symbol, which
2452	indicates the vfork() routine is available.
2453
2454d_void_closedir (d_closedir.U):
2455	This variable conditionally defines VOID_CLOSEDIR if closedir()
2456	does not return a value.
2457
2458d_voidsig (d_voidsig.U):
2459	This variable conditionally defines VOIDSIG if this system
2460	declares "void (*signal(...))()" in signal.h.  The old way was to
2461	declare it as "int (*signal(...))()".
2462
2463d_voidtty (i_sysioctl.U):
2464	This variable conditionally defines USE_IOCNOTTY to indicate that the
2465	ioctl() call with TIOCNOTTY should be used to void tty association.
2466	Otherwise (on USG probably), it is enough to close the standard file
2467	descriptors and do a setpgrp().
2468
2469d_volatile (d_volatile.U):
2470	This variable conditionally defines the HASVOLATILE symbol, which
2471	indicates to the C program that this C compiler knows about the
2472	volatile declaration.
2473
2474d_vprintf (d_vprintf.U):
2475	This variable conditionally defines the HAS_VPRINTF symbol, which
2476	indicates to the C program that the vprintf() routine is available
2477	to printf with a pointer to an argument list.
2478
2479d_vsnprintf (d_snprintf.U):
2480	This variable conditionally defines the HAS_VSNPRINTF symbol, which
2481	indicates to the C program that the vsnprintf () library function
2482	is available.
2483
2484d_wait4 (d_wait4.U):
2485	This variable conditionally defines the HAS_WAIT4 symbol, which
2486	indicates the wait4() routine is available.
2487
2488d_waitpid (d_waitpid.U):
2489	This variable conditionally defines HAS_WAITPID if waitpid() is
2490	available to wait for child process.
2491
2492d_wcstombs (d_wcstombs.U):
2493	This variable conditionally defines the HAS_WCSTOMBS symbol, which
2494	indicates to the C program that the wcstombs() routine is available
2495	to convert wide character strings to multibyte strings.
2496
2497d_wctomb (d_wctomb.U):
2498	This variable conditionally defines the HAS_WCTOMB symbol, which
2499	indicates to the C program that the wctomb() routine is available
2500	to convert a wide character to a multibyte.
2501
2502d_writev (d_writev.U):
2503	This variable conditionally defines the HAS_WRITEV symbol, which
2504	indicates to the C program that the writev() routine is available.
2505
2506d_xenix (Guess.U):
2507	This variable conditionally defines the symbol XENIX, which alerts
2508	the C program that it runs under Xenix.
2509
2510date (Loc.U):
2511	This variable is used internally by Configure to determine the
2512	full pathname (if any) of the date program.  After Configure runs,
2513	the value is reset to a plain "date" and is not useful.
2514
2515db_hashtype (i_db.U):
2516	This variable contains the type of the hash structure element
2517	in the <db.h> header file.  In older versions of DB, it was
2518	int, while in newer ones it is u_int32_t.
2519
2520db_prefixtype (i_db.U):
2521	This variable contains the type of the prefix structure element
2522	in the <db.h> header file.  In older versions of DB, it was
2523	int, while in newer ones it is size_t.
2524
2525db_version_major (i_db.U):
2526	This variable contains the major version number of
2527	Berkeley DB found in the <db.h> header file.
2528
2529db_version_minor (i_db.U):
2530	This variable contains the minor version number of
2531	Berkeley DB found in the <db.h> header file.
2532	For DB version 1 this is always 0.
2533
2534db_version_patch (i_db.U):
2535	This variable contains the patch version number of
2536	Berkeley DB found in the <db.h> header file.
2537	For DB version 1 this is always 0.
2538
2539defvoidused (voidflags.U):
2540	This variable contains the default value of the VOIDUSED symbol (15).
2541
2542direntrytype (i_dirent.U):
2543	This symbol is set to 'struct direct' or 'struct dirent' depending on
2544	whether dirent is available or not. You should use this pseudo type to
2545	portably declare your directory entries.
2546
2547dlext (dlext.U):
2548	This variable contains the extension that is to be used for the
2549	dynamically loaded modules that perl generaties.
2550
2551dlsrc (dlsrc.U):
2552	This variable contains the name of the dynamic loading file that
2553	will be used with the package.
2554
2555doublesize (doublesize.U):
2556	This variable contains the value of the DOUBLESIZE symbol, which
2557	indicates to the C program how many bytes there are in a double.
2558
2559drand01 (randfunc.U):
2560	Indicates the macro to be used to generate normalized
2561	random numbers.  Uses randfunc, often divided by
2562	(double) (((unsigned long) 1 << randbits)) in order to
2563	normalize the result.
2564	In C programs, the macro 'Drand01' is mapped to drand01.
2565
2566drand48_r_proto (d_drand48_r.U):
2567	This variable encodes the prototype of drand48_r.
2568	It is zero if d_drand48_r is undef, and one of the
2569	REENTRANT_PROTO_T_ABC macros of reentr.h if d_drand48_r
2570	is defined.
2571
2572dtrace (usedtrace.U):
2573	This variable holds the location of the dtrace executable.
2574
2575dynamic_ext (Extensions.U):
2576	This variable holds a list of XS extension files we want to
2577	link dynamically into the package.  It is used by Makefile.
2578
2579eagain (nblock_io.U):
2580	This variable bears the symbolic errno code set by read() when no
2581	data is present on the file and non-blocking I/O was enabled (otherwise,
2582	read() blocks naturally).
2583
2584ebcdic (ebcdic.U):
2585	This variable conditionally defines EBCDIC if this
2586	system uses EBCDIC encoding.  Among other things, this
2587	means that the character ranges are not contiguous.
2588	See trnl.U
2589
2590echo (Loc.U):
2591	This variable is used internally by Configure to determine the
2592	full pathname (if any) of the echo program.  After Configure runs,
2593	the value is reset to a plain "echo" and is not useful.
2594
2595egrep (Loc.U):
2596	This variable is used internally by Configure to determine the
2597	full pathname (if any) of the egrep program.  After Configure runs,
2598	the value is reset to a plain "egrep" and is not useful.
2599
2600emacs (Loc.U):
2601	This variable is defined but not used by Configure.
2602	The value is the empty string and is not useful.
2603
2604endgrent_r_proto (d_endgrent_r.U):
2605	This variable encodes the prototype of endgrent_r.
2606	It is zero if d_endgrent_r is undef, and one of the
2607	REENTRANT_PROTO_T_ABC macros of reentr.h if d_endgrent_r
2608	is defined.
2609
2610endhostent_r_proto (d_endhostent_r.U):
2611	This variable encodes the prototype of endhostent_r.
2612	It is zero if d_endhostent_r is undef, and one of the
2613	REENTRANT_PROTO_T_ABC macros of reentr.h if d_endhostent_r
2614	is defined.
2615
2616endnetent_r_proto (d_endnetent_r.U):
2617	This variable encodes the prototype of endnetent_r.
2618	It is zero if d_endnetent_r is undef, and one of the
2619	REENTRANT_PROTO_T_ABC macros of reentr.h if d_endnetent_r
2620	is defined.
2621
2622endprotoent_r_proto (d_endprotoent_r.U):
2623	This variable encodes the prototype of endprotoent_r.
2624	It is zero if d_endprotoent_r is undef, and one of the
2625	REENTRANT_PROTO_T_ABC macros of reentr.h if d_endprotoent_r
2626	is defined.
2627
2628endpwent_r_proto (d_endpwent_r.U):
2629	This variable encodes the prototype of endpwent_r.
2630	It is zero if d_endpwent_r is undef, and one of the
2631	REENTRANT_PROTO_T_ABC macros of reentr.h if d_endpwent_r
2632	is defined.
2633
2634endservent_r_proto (d_endservent_r.U):
2635	This variable encodes the prototype of endservent_r.
2636	It is zero if d_endservent_r is undef, and one of the
2637	REENTRANT_PROTO_T_ABC macros of reentr.h if d_endservent_r
2638	is defined.
2639
2640eunicefix (Init.U):
2641	When running under Eunice this variable contains a command which will
2642	convert a shell script to the proper form of text file for it to be
2643	executable by the shell.  On other systems it is a no-op.
2644
2645exe_ext (Unix.U):
2646	This is an old synonym for _exe.
2647
2648expr (Loc.U):
2649	This variable is used internally by Configure to determine the
2650	full pathname (if any) of the expr program.  After Configure runs,
2651	the value is reset to a plain "expr" and is not useful.
2652
2653extensions (Extensions.U):
2654	This variable holds a list of all extension files (both XS and
2655	non-xs linked into the package.  It is propagated to Config.pm
2656	and is typically used to test whether a particular extension
2657	is available.
2658
2659extern_C (Csym.U):
2660	ANSI C requires 'extern' where C++ requires 'extern "C"'. This
2661	variable can be used in Configure to do the right thing.
2662
2663extras (Extras.U):
2664	This variable holds a list of extra modules to install.
2665
2666fflushall (fflushall.U):
2667	This symbol, if defined, tells that to flush
2668	all pending stdio output one must loop through all
2669	the stdio file handles stored in an array and fflush them.
2670	Note that if fflushNULL is defined, fflushall will not
2671	even be probed for and will be left undefined.
2672
2673fflushNULL (fflushall.U):
2674	This symbol, if defined, tells that fflush(NULL) does flush
2675	all pending stdio output.
2676
2677find (Loc.U):
2678	This variable is defined but not used by Configure.
2679	The value is the empty string and is not useful.
2680
2681firstmakefile (Unix.U):
2682	This variable defines the first file searched by make.  On unix,
2683	it is makefile (then Makefile).  On case-insensitive systems,
2684	it might be something else.  This is only used to deal with
2685	convoluted make depend tricks.
2686
2687flex (Loc.U):
2688	This variable is defined but not used by Configure.
2689	The value is the empty string and is not useful.
2690
2691fpossize (fpossize.U):
2692	This variable contains the size of a fpostype in bytes.
2693
2694fpostype (fpostype.U):
2695	This variable defines Fpos_t to be something like fpos_t, long,
2696	uint, or whatever type is used to declare file positions in libc.
2697
2698freetype (mallocsrc.U):
2699	This variable contains the return type of free().  It is usually
2700	void, but occasionally int.
2701
2702from (Cross.U):
2703	This variable contains the command used by Configure
2704	to copy files from the target host.  Useful and available
2705	only during Perl build.
2706	The string ':' if not cross-compiling.
2707
2708full_ar (Loc_ar.U):
2709	This variable contains the full pathname to 'ar', whether or
2710	not the user has specified 'portability'.  This is only used
2711	in the Makefile.SH.
2712
2713full_csh (d_csh.U):
2714	This variable contains the full pathname to 'csh', whether or
2715	not the user has specified 'portability'.  This is only used
2716	in the compiled C program, and we assume that all systems which
2717	can share this executable will have the same full pathname to
2718	'csh.'
2719
2720full_sed (Loc_sed.U):
2721	This variable contains the full pathname to 'sed', whether or
2722	not the user has specified 'portability'.  This is only used
2723	in the compiled C program, and we assume that all systems which
2724	can share this executable will have the same full pathname to
2725	'sed.'
2726
2727gccansipedantic (gccvers.U):
2728	If GNU cc (gcc) is used, this variable will enable (if set) the
2729	-ansi and -pedantic ccflags for building core files (through
2730	cflags script). (See Porting/pumpkin.pod for full description).
2731
2732gccosandvers (gccvers.U):
2733	If GNU cc (gcc) is used, this variable holds the operating system
2734	and version used to compile gcc.  It is set to '' if not gcc,
2735	or if nothing useful can be parsed as the os version.
2736
2737gccversion (gccvers.U):
2738	If GNU cc (gcc) is used, this variable holds '1' or '2' to
2739	indicate whether the compiler is version 1 or 2.  This is used in
2740	setting some of the default cflags.  It is set to '' if not gcc.
2741
2742getgrent_r_proto (d_getgrent_r.U):
2743	This variable encodes the prototype of getgrent_r.
2744	It is zero if d_getgrent_r is undef, and one of the
2745	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getgrent_r
2746	is defined.
2747
2748getgrgid_r_proto (d_getgrgid_r.U):
2749	This variable encodes the prototype of getgrgid_r.
2750	It is zero if d_getgrgid_r is undef, and one of the
2751	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getgrgid_r
2752	is defined.
2753
2754getgrnam_r_proto (d_getgrnam_r.U):
2755	This variable encodes the prototype of getgrnam_r.
2756	It is zero if d_getgrnam_r is undef, and one of the
2757	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getgrnam_r
2758	is defined.
2759
2760gethostbyaddr_r_proto (d_gethostbyaddr_r.U):
2761	This variable encodes the prototype of gethostbyaddr_r.
2762	It is zero if d_gethostbyaddr_r is undef, and one of the
2763	REENTRANT_PROTO_T_ABC macros of reentr.h if d_gethostbyaddr_r
2764	is defined.
2765
2766gethostbyname_r_proto (d_gethostbyname_r.U):
2767	This variable encodes the prototype of gethostbyname_r.
2768	It is zero if d_gethostbyname_r is undef, and one of the
2769	REENTRANT_PROTO_T_ABC macros of reentr.h if d_gethostbyname_r
2770	is defined.
2771
2772gethostent_r_proto (d_gethostent_r.U):
2773	This variable encodes the prototype of gethostent_r.
2774	It is zero if d_gethostent_r is undef, and one of the
2775	REENTRANT_PROTO_T_ABC macros of reentr.h if d_gethostent_r
2776	is defined.
2777
2778getlogin_r_proto (d_getlogin_r.U):
2779	This variable encodes the prototype of getlogin_r.
2780	It is zero if d_getlogin_r is undef, and one of the
2781	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getlogin_r
2782	is defined.
2783
2784getnetbyaddr_r_proto (d_getnetbyaddr_r.U):
2785	This variable encodes the prototype of getnetbyaddr_r.
2786	It is zero if d_getnetbyaddr_r is undef, and one of the
2787	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getnetbyaddr_r
2788	is defined.
2789
2790getnetbyname_r_proto (d_getnetbyname_r.U):
2791	This variable encodes the prototype of getnetbyname_r.
2792	It is zero if d_getnetbyname_r is undef, and one of the
2793	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getnetbyname_r
2794	is defined.
2795
2796getnetent_r_proto (d_getnetent_r.U):
2797	This variable encodes the prototype of getnetent_r.
2798	It is zero if d_getnetent_r is undef, and one of the
2799	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getnetent_r
2800	is defined.
2801
2802getprotobyname_r_proto (d_getprotobyname_r.U):
2803	This variable encodes the prototype of getprotobyname_r.
2804	It is zero if d_getprotobyname_r is undef, and one of the
2805	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getprotobyname_r
2806	is defined.
2807
2808getprotobynumber_r_proto (d_getprotobynumber_r.U):
2809	This variable encodes the prototype of getprotobynumber_r.
2810	It is zero if d_getprotobynumber_r is undef, and one of the
2811	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getprotobynumber_r
2812	is defined.
2813
2814getprotoent_r_proto (d_getprotoent_r.U):
2815	This variable encodes the prototype of getprotoent_r.
2816	It is zero if d_getprotoent_r is undef, and one of the
2817	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getprotoent_r
2818	is defined.
2819
2820getpwent_r_proto (d_getpwent_r.U):
2821	This variable encodes the prototype of getpwent_r.
2822	It is zero if d_getpwent_r is undef, and one of the
2823	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getpwent_r
2824	is defined.
2825
2826getpwnam_r_proto (d_getpwnam_r.U):
2827	This variable encodes the prototype of getpwnam_r.
2828	It is zero if d_getpwnam_r is undef, and one of the
2829	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getpwnam_r
2830	is defined.
2831
2832getpwuid_r_proto (d_getpwuid_r.U):
2833	This variable encodes the prototype of getpwuid_r.
2834	It is zero if d_getpwuid_r is undef, and one of the
2835	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getpwuid_r
2836	is defined.
2837
2838getservbyname_r_proto (d_getservbyname_r.U):
2839	This variable encodes the prototype of getservbyname_r.
2840	It is zero if d_getservbyname_r is undef, and one of the
2841	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getservbyname_r
2842	is defined.
2843
2844getservbyport_r_proto (d_getservbyport_r.U):
2845	This variable encodes the prototype of getservbyport_r.
2846	It is zero if d_getservbyport_r is undef, and one of the
2847	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getservbyport_r
2848	is defined.
2849
2850getservent_r_proto (d_getservent_r.U):
2851	This variable encodes the prototype of getservent_r.
2852	It is zero if d_getservent_r is undef, and one of the
2853	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getservent_r
2854	is defined.
2855
2856getspnam_r_proto (d_getspnam_r.U):
2857	This variable encodes the prototype of getspnam_r.
2858	It is zero if d_getspnam_r is undef, and one of the
2859	REENTRANT_PROTO_T_ABC macros of reentr.h if d_getspnam_r
2860	is defined.
2861
2862gidformat (gidf.U):
2863	This variable contains the format string used for printing a Gid_t.
2864
2865gidsign (gidsign.U):
2866	This variable contains the signedness of a gidtype.
2867	1 for unsigned, -1 for signed.
2868
2869gidsize (gidsize.U):
2870	This variable contains the size of a gidtype in bytes.
2871
2872gidtype (gidtype.U):
2873	This variable defines Gid_t to be something like gid_t, int,
2874	ushort, or whatever type is used to declare the return type
2875	of getgid().  Typically, it is the type of group ids in the kernel.
2876
2877glibpth (libpth.U):
2878	This variable holds the general path (space-separated) used to
2879	find libraries.  It may contain directories that do not exist on
2880	this platform, libpth is the cleaned-up version.
2881
2882gmake (Loc.U):
2883	This variable is used internally by Configure to determine the
2884	full pathname (if any) of the gmake program.  After Configure runs,
2885	the value is reset to a plain "gmake" and is not useful.
2886
2887gmtime_r_proto (d_gmtime_r.U):
2888	This variable encodes the prototype of gmtime_r.
2889	It is zero if d_gmtime_r is undef, and one of the
2890	REENTRANT_PROTO_T_ABC macros of reentr.h if d_gmtime_r
2891	is defined.
2892
2893gnulibc_version (d_gnulibc.U):
2894	This variable contains the version number of the GNU C library.
2895	It is usually something like '2.2.5'.  It is a plain '' if this
2896	is not the GNU C library, or if the version is unknown.
2897
2898grep (Loc.U):
2899	This variable is used internally by Configure to determine the
2900	full pathname (if any) of the grep program.  After Configure runs,
2901	the value is reset to a plain "grep" and is not useful.
2902
2903groupcat (nis.U):
2904	This variable contains a command that produces the text of the
2905	/etc/group file.  This is normally "cat /etc/group", but can be
2906	"ypcat group" when NIS is used.
2907	On some systems, such as os390, there may be no equivalent
2908	command, in which case this variable is unset.
2909
2910groupstype (groupstype.U):
2911	This variable defines Groups_t to be something like gid_t, int,
2912	ushort, or whatever type is used for the second argument to
2913	getgroups() and setgroups().  Usually, this is the same as
2914	gidtype (gid_t), but sometimes it isn't.
2915
2916gzip (Loc.U):
2917	This variable is used internally by Configure to determine the
2918	full pathname (if any) of the gzip program.  After Configure runs,
2919	the value is reset to a plain "gzip" and is not useful.
2920
2921h_fcntl (h_fcntl.U):
2922	This is variable gets set in various places to tell i_fcntl that
2923	<fcntl.h> should be included.
2924
2925h_sysfile (h_sysfile.U):
2926	This is variable gets set in various places to tell i_sys_file that
2927	<sys/file.h> should be included.
2928
2929hint (Oldconfig.U):
2930	Gives the type of hints used for previous answers. May be one of
2931	"default", "recommended" or "previous".
2932
2933hostcat (nis.U):
2934	This variable contains a command that produces the text of the
2935	/etc/hosts file.  This is normally "cat /etc/hosts", but can be
2936	"ypcat hosts" when NIS is used.
2937	On some systems, such as os390, there may be no equivalent
2938	command, in which case this variable is unset.
2939
2940html1dir (html1dir.U):
2941	This variable contains the name of the directory in which html
2942	source pages are to be put.  This directory is for pages
2943	that describe whole programs, not libraries or modules.  It
2944	is intended to correspond roughly to section 1 of the Unix
2945	manuals.
2946
2947html1direxp (html1dir.U):
2948	This variable is the same as the html1dir variable, but is filename
2949	expanded at configuration time, for convenient use in makefiles.
2950
2951html3dir (html3dir.U):
2952	This variable contains the name of the directory in which html
2953	source pages are to be put.  This directory is for pages
2954	that describe libraries or modules.  It is intended to
2955	correspond roughly to section 3 of the Unix manuals.
2956
2957html3direxp (html3dir.U):
2958	This variable is the same as the html3dir variable, but is filename
2959	expanded at configuration time, for convenient use in makefiles.
2960
2961i16size (perlxv.U):
2962	This variable is the size of an I16 in bytes.
2963
2964i16type (perlxv.U):
2965	This variable contains the C type used for Perl's I16.
2966
2967i32size (perlxv.U):
2968	This variable is the size of an I32 in bytes.
2969
2970i32type (perlxv.U):
2971	This variable contains the C type used for Perl's I32.
2972
2973i64size (perlxv.U):
2974	This variable is the size of an I64 in bytes.
2975
2976i64type (perlxv.U):
2977	This variable contains the C type used for Perl's I64.
2978
2979i8size (perlxv.U):
2980	This variable is the size of an I8 in bytes.
2981
2982i8type (perlxv.U):
2983	This variable contains the C type used for Perl's I8.
2984
2985i_arpainet (i_arpainet.U):
2986	This variable conditionally defines the I_ARPA_INET symbol,
2987	and indicates whether a C program should include <arpa/inet.h>.
2988
2989i_assert (i_assert.U):
2990	This variable conditionally defines the I_ASSERT symbol, which
2991	indicates to the C program that <assert.h> exists and could be
2992	included.
2993
2994i_bsdioctl (i_sysioctl.U):
2995	This variable conditionally defines the I_SYS_BSDIOCTL symbol, which
2996	indicates to the C program that <sys/bsdioctl.h> exists and should
2997	be included.
2998
2999i_crypt (i_crypt.U):
3000	This variable conditionally defines the I_CRYPT symbol, and indicates
3001	whether a C program should include <crypt.h>.
3002
3003i_db (i_db.U):
3004	This variable conditionally defines the I_DB symbol, and indicates
3005	whether a C program may include Berkeley's DB include file <db.h>.
3006
3007i_dbm (i_dbm.U):
3008	This variable conditionally defines the I_DBM symbol, which
3009	indicates to the C program that <dbm.h> exists and should
3010	be included.
3011
3012i_dirent (i_dirent.U):
3013	This variable conditionally defines I_DIRENT, which indicates
3014	to the C program that it should include <dirent.h>.
3015
3016i_dld (i_dld.U):
3017	This variable conditionally defines the I_DLD symbol, which
3018	indicates to the C program that <dld.h> (GNU dynamic loading)
3019	exists and should be included.
3020
3021i_dlfcn (i_dlfcn.U):
3022	This variable conditionally defines the I_DLFCN symbol, which
3023	indicates to the C program that <dlfcn.h> exists and should
3024	be included.
3025
3026i_fcntl (i_fcntl.U):
3027	This variable controls the value of I_FCNTL (which tells
3028	the C program to include <fcntl.h>).
3029
3030i_float (i_float.U):
3031	This variable conditionally defines the I_FLOAT symbol, and indicates
3032	whether a C program may include <float.h> to get symbols like DBL_MAX
3033	or DBL_MIN, i.e. machine dependent floating point values.
3034
3035i_fp (i_fp.U):
3036	This variable conditionally defines the I_FP symbol, and indicates
3037	whether a C program should include <fp.h>.
3038
3039i_fp_class (i_fp_class.U):
3040	This variable conditionally defines the I_FP_CLASS symbol, and indicates
3041	whether a C program should include <fp_class.h>.
3042
3043i_gdbm (i_gdbm.U):
3044	This variable conditionally defines the I_GDBM symbol, which
3045	indicates to the C program that <gdbm.h> exists and should
3046	be included.
3047
3048i_gdbm_ndbm (i_ndbm.U):
3049	This variable conditionally defines the I_GDBM_NDBM symbol, which
3050	indicates to the C program that <gdbm-ndbm.h> exists and should
3051	be included.  This is the location of the ndbm.h compatibility file
3052	in Debian 4.0.
3053
3054i_gdbmndbm (i_ndbm.U):
3055	This variable conditionally defines the I_GDBMNDBM symbol, which
3056	indicates to the C program that <gdbm/ndbm.h> exists and should
3057	be included.  This was the location of the ndbm.h compatibility file
3058	in RedHat 7.1.
3059
3060i_grp (i_grp.U):
3061	This variable conditionally defines the I_GRP symbol, and indicates
3062	whether a C program should include <grp.h>.
3063
3064i_ieeefp (i_ieeefp.U):
3065	This variable conditionally defines the I_IEEEFP symbol, and indicates
3066	whether a C program should include <ieeefp.h>.
3067
3068i_inttypes (i_inttypes.U):
3069	This variable conditionally defines the I_INTTYPES symbol,
3070	and indicates whether a C program should include <inttypes.h>.
3071
3072i_langinfo (i_langinfo.U):
3073	This variable conditionally defines the I_LANGINFO symbol,
3074	and indicates whether a C program should include <langinfo.h>.
3075
3076i_libutil (i_libutil.U):
3077	This variable conditionally defines the I_LIBUTIL symbol, and indicates
3078	whether a C program should include <libutil.h>.
3079
3080i_limits (i_limits.U):
3081	This variable conditionally defines the I_LIMITS symbol, and indicates
3082	whether a C program may include <limits.h> to get symbols like WORD_BIT
3083	and friends.
3084
3085i_locale (i_locale.U):
3086	This variable conditionally defines the I_LOCALE symbol,
3087	and indicates whether a C program should include <locale.h>.
3088
3089i_machcthr (i_machcthr.U):
3090	This variable conditionally defines the I_MACH_CTHREADS symbol,
3091	and indicates whether a C program should include <mach/cthreads.h>.
3092
3093i_malloc (i_malloc.U):
3094	This variable conditionally defines the I_MALLOC symbol, and indicates
3095	whether a C program should include <malloc.h>.
3096
3097i_mallocmalloc (i_mallocmalloc.U):
3098	This variable conditionally defines the I_MALLOCMALLOC symbol,
3099	and indicates whether a C program should include <malloc/malloc.h>.
3100
3101i_math (i_math.U):
3102	This variable conditionally defines the I_MATH symbol, and indicates
3103	whether a C program may include <math.h>.
3104
3105i_memory (i_memory.U):
3106	This variable conditionally defines the I_MEMORY symbol, and indicates
3107	whether a C program should include <memory.h>.
3108
3109i_mntent (i_mntent.U):
3110	This variable conditionally defines the I_MNTENT symbol, and indicates
3111	whether a C program should include <mntent.h>.
3112
3113i_ndbm (i_ndbm.U):
3114	This variable conditionally defines the I_NDBM symbol, which
3115	indicates to the C program that <ndbm.h> exists and should
3116	be included.
3117
3118i_netdb (i_netdb.U):
3119	This variable conditionally defines the I_NETDB symbol, and indicates
3120	whether a C program should include <netdb.h>.
3121
3122i_neterrno (i_neterrno.U):
3123	This variable conditionally defines the I_NET_ERRNO symbol, which
3124	indicates to the C program that <net/errno.h> exists and should
3125	be included.
3126
3127i_netinettcp (i_netinettcp.U):
3128	This variable conditionally defines the I_NETINET_TCP symbol,
3129	and indicates whether a C program should include <netinet/tcp.h>.
3130
3131i_niin (i_niin.U):
3132	This variable conditionally defines I_NETINET_IN, which indicates
3133	to the C program that it should include <netinet/in.h>. Otherwise,
3134	you may try <sys/in.h>.
3135
3136i_poll (i_poll.U):
3137	This variable conditionally defines the I_POLL symbol, and indicates
3138	whether a C program should include <poll.h>.
3139
3140i_prot (i_prot.U):
3141	This variable conditionally defines the I_PROT symbol, and indicates
3142	whether a C program should include <prot.h>.
3143
3144i_pthread (i_pthread.U):
3145	This variable conditionally defines the I_PTHREAD symbol,
3146	and indicates whether a C program should include <pthread.h>.
3147
3148i_pwd (i_pwd.U):
3149	This variable conditionally defines I_PWD, which indicates
3150	to the C program that it should include <pwd.h>.
3151
3152i_rpcsvcdbm (i_dbm.U):
3153	This variable conditionally defines the I_RPCSVC_DBM symbol, which
3154	indicates to the C program that <rpcsvc/dbm.h> exists and should
3155	be included.  Some System V systems might need this instead of <dbm.h>.
3156
3157i_sfio (i_sfio.U):
3158	This variable conditionally defines the I_SFIO symbol,
3159	and indicates whether a C program should include <sfio.h>.
3160
3161i_sgtty (i_termio.U):
3162	This variable conditionally defines the I_SGTTY symbol, which
3163	indicates to the C program that it should include <sgtty.h> rather
3164	than <termio.h>.
3165
3166i_shadow (i_shadow.U):
3167	This variable conditionally defines the I_SHADOW symbol, and indicates
3168	whether a C program should include <shadow.h>.
3169
3170i_socks (i_socks.U):
3171	This variable conditionally defines the I_SOCKS symbol, and indicates
3172	whether a C program should include <socks.h>.
3173
3174i_stdarg (i_varhdr.U):
3175	This variable conditionally defines the I_STDARG symbol, which
3176	indicates to the C program that <stdarg.h> exists and should
3177	be included.
3178
3179i_stdbool (i_stdbool.U):
3180	This variable conditionally defines the I_STDBOOL symbol, which
3181	indicates to the C program that <stdbool.h> exists and should
3182	be included.
3183
3184i_stddef (i_stddef.U):
3185	This variable conditionally defines the I_STDDEF symbol, which
3186	indicates to the C program that <stddef.h> exists and should
3187	be included.
3188
3189i_stdlib (i_stdlib.U):
3190	This variable conditionally defines the I_STDLIB symbol, which
3191	indicates to the C program that <stdlib.h> exists and should
3192	be included.
3193
3194i_string (i_string.U):
3195	This variable conditionally defines the I_STRING symbol, which
3196	indicates that <string.h> should be included rather than <strings.h>.
3197
3198i_sunmath (i_sunmath.U):
3199	This variable conditionally defines the I_SUNMATH symbol, and indicates
3200	whether a C program should include <sunmath.h>.
3201
3202i_sysaccess (i_sysaccess.U):
3203	This variable conditionally defines the I_SYS_ACCESS symbol,
3204	and indicates whether a C program should include <sys/access.h>.
3205
3206i_sysdir (i_sysdir.U):
3207	This variable conditionally defines the I_SYS_DIR symbol, and indicates
3208	whether a C program should include <sys/dir.h>.
3209
3210i_sysfile (i_sysfile.U):
3211	This variable conditionally defines the I_SYS_FILE symbol, and indicates
3212	whether a C program should include <sys/file.h> to get R_OK and friends.
3213
3214i_sysfilio (i_sysioctl.U):
3215	This variable conditionally defines the I_SYS_FILIO symbol, which
3216	indicates to the C program that <sys/filio.h> exists and should
3217	be included in preference to <sys/ioctl.h>.
3218
3219i_sysin (i_niin.U):
3220	This variable conditionally defines I_SYS_IN, which indicates
3221	to the C program that it should include <sys/in.h> instead of
3222	<netinet/in.h>.
3223
3224i_sysioctl (i_sysioctl.U):
3225	This variable conditionally defines the I_SYS_IOCTL symbol, which
3226	indicates to the C program that <sys/ioctl.h> exists and should
3227	be included.
3228
3229i_syslog (i_syslog.U):
3230	This variable conditionally defines the I_SYSLOG symbol,
3231	and indicates whether a C program should include <syslog.h>.
3232
3233i_sysmman (i_sysmman.U):
3234	This variable conditionally defines the I_SYS_MMAN symbol, and
3235	indicates whether a C program should include <sys/mman.h>.
3236
3237i_sysmode (i_sysmode.U):
3238	This variable conditionally defines the I_SYSMODE symbol,
3239	and indicates whether a C program should include <sys/mode.h>.
3240
3241i_sysmount (i_sysmount.U):
3242	This variable conditionally defines the I_SYSMOUNT symbol,
3243	and indicates whether a C program should include <sys/mount.h>.
3244
3245i_sysndir (i_sysndir.U):
3246	This variable conditionally defines the I_SYS_NDIR symbol, and indicates
3247	whether a C program should include <sys/ndir.h>.
3248
3249i_sysparam (i_sysparam.U):
3250	This variable conditionally defines the I_SYS_PARAM symbol, and indicates
3251	whether a C program should include <sys/param.h>.
3252
3253i_syspoll (i_syspoll.U):
3254	This variable conditionally defines the I_SYS_POLL symbol, which
3255	indicates to the C program that it should include <sys/poll.h>.
3256
3257i_sysresrc (i_sysresrc.U):
3258	This variable conditionally defines the I_SYS_RESOURCE symbol,
3259	and indicates whether a C program should include <sys/resource.h>.
3260
3261i_syssecrt (i_syssecrt.U):
3262	This variable conditionally defines the I_SYS_SECURITY symbol,
3263	and indicates whether a C program should include <sys/security.h>.
3264
3265i_sysselct (i_sysselct.U):
3266	This variable conditionally defines I_SYS_SELECT, which indicates
3267	to the C program that it should include <sys/select.h> in order to
3268	get the definition of struct timeval.
3269
3270i_syssockio (i_sysioctl.U):
3271	This variable conditionally defines I_SYS_SOCKIO to indicate to the
3272	C program that socket ioctl codes may be found in <sys/sockio.h>
3273	instead of <sys/ioctl.h>.
3274
3275i_sysstat (i_sysstat.U):
3276	This variable conditionally defines the I_SYS_STAT symbol,
3277	and indicates whether a C program should include <sys/stat.h>.
3278
3279i_sysstatfs (i_sysstatfs.U):
3280	This variable conditionally defines the I_SYSSTATFS symbol,
3281	and indicates whether a C program should include <sys/statfs.h>.
3282
3283i_sysstatvfs (i_sysstatvfs.U):
3284	This variable conditionally defines the I_SYSSTATVFS symbol,
3285	and indicates whether a C program should include <sys/statvfs.h>.
3286
3287i_systime (i_time.U):
3288	This variable conditionally defines I_SYS_TIME, which indicates
3289	to the C program that it should include <sys/time.h>.
3290
3291i_systimek (i_time.U):
3292	This variable conditionally defines I_SYS_TIME_KERNEL, which
3293	indicates to the C program that it should include <sys/time.h>
3294	with KERNEL defined.
3295
3296i_systimes (i_systimes.U):
3297	This variable conditionally defines the I_SYS_TIMES symbol, and indicates
3298	whether a C program should include <sys/times.h>.
3299
3300i_systypes (i_systypes.U):
3301	This variable conditionally defines the I_SYS_TYPES symbol,
3302	and indicates whether a C program should include <sys/types.h>.
3303
3304i_sysuio (i_sysuio.U):
3305	This variable conditionally defines the I_SYSUIO symbol, and indicates
3306	whether a C program should include <sys/uio.h>.
3307
3308i_sysun (i_sysun.U):
3309	This variable conditionally defines I_SYS_UN, which indicates
3310	to the C program that it should include <sys/un.h> to get UNIX
3311	domain socket definitions.
3312
3313i_sysutsname (i_sysutsname.U):
3314	This variable conditionally defines the I_SYSUTSNAME symbol,
3315	and indicates whether a C program should include <sys/utsname.h>.
3316
3317i_sysvfs (i_sysvfs.U):
3318	This variable conditionally defines the I_SYSVFS symbol,
3319	and indicates whether a C program should include <sys/vfs.h>.
3320
3321i_syswait (i_syswait.U):
3322	This variable conditionally defines I_SYS_WAIT, which indicates
3323	to the C program that it should include <sys/wait.h>.
3324
3325i_termio (i_termio.U):
3326	This variable conditionally defines the I_TERMIO symbol, which
3327	indicates to the C program that it should include <termio.h> rather
3328	than <sgtty.h>.
3329
3330i_termios (i_termio.U):
3331	This variable conditionally defines the I_TERMIOS symbol, which
3332	indicates to the C program that the POSIX <termios.h> file is
3333	to be included.
3334
3335i_time (i_time.U):
3336	This variable conditionally defines I_TIME, which indicates
3337	to the C program that it should include <time.h>.
3338
3339i_unistd (i_unistd.U):
3340	This variable conditionally defines the I_UNISTD symbol, and indicates
3341	whether a C program should include <unistd.h>.
3342
3343i_ustat (i_ustat.U):
3344	This variable conditionally defines the I_USTAT symbol, and indicates
3345	whether a C program should include <ustat.h>.
3346
3347i_utime (i_utime.U):
3348	This variable conditionally defines the I_UTIME symbol, and indicates
3349	whether a C program should include <utime.h>.
3350
3351i_values (i_values.U):
3352	This variable conditionally defines the I_VALUES symbol, and indicates
3353	whether a C program may include <values.h> to get symbols like MAXLONG
3354	and friends.
3355
3356i_varargs (i_varhdr.U):
3357	This variable conditionally defines I_VARARGS, which indicates
3358	to the C program that it should include <varargs.h>.
3359
3360i_varhdr (i_varhdr.U):
3361	Contains the name of the header to be included to get va_dcl definition.
3362	Typically one of varargs.h or stdarg.h.
3363
3364i_vfork (i_vfork.U):
3365	This variable conditionally defines the I_VFORK symbol, and indicates
3366	whether a C program should include vfork.h.
3367
3368ignore_versioned_solibs (libs.U):
3369	This variable should be non-empty if non-versioned shared
3370	libraries (libfoo.so.x.y) are to be ignored (because they
3371	cannot be linked against).
3372
3373inc_version_list (inc_version_list.U):
3374	This variable specifies the list of subdirectories in over
3375	which perl.c:incpush() and lib/lib.pm will automatically
3376	search when adding directories to @INC.  The elements in
3377	the list are separated by spaces.  This is only useful
3378	if you have a perl library directory tree structured like the
3379	default one.  See INSTALL for how this works.  The versioned
3380	site_perl directory was introduced in 5.005, so that is the
3381	lowest possible value.
3382
3383	This list includes architecture-dependent directories back to
3384	version $api_versionstring (e.g. 5.5.640) and
3385	architecture-independent directories all the way back to
3386	5.005.
3387
3388inc_version_list_init (inc_version_list.U):
3389	This variable holds the same list as inc_version_list, but
3390	each item is enclosed in double quotes and separated by commas,
3391	suitable for use in the PERL_INC_VERSION_LIST initialization.
3392
3393incpath (usrinc.U):
3394	This variable must precede the normal include path to get the
3395	right one, as in "$incpath/usr/include" or "$incpath/usr/lib".
3396	Value can be "" or "/bsd43" on mips.
3397
3398inews (Loc.U):
3399	This variable is defined but not used by Configure.
3400	The value is the empty string and is not useful.
3401
3402initialinstalllocation (bin.U):
3403	When userelocatableinc is true, this variable holds the location
3404	that make install should copy the perl binary to, with all the
3405	run-time relocatable paths calculated from this at install time.
3406	When used, it is initialised to the original value of binexp, and
3407	then binexp is set to '.../', as the other binaries are found
3408	relative to the perl binary.
3409
3410installarchlib (archlib.U):
3411	This variable is really the same as archlibexp but may differ on
3412	those systems using AFS. For extra portability, only this variable
3413	should be used in makefiles.
3414
3415installbin (bin.U):
3416	This variable is the same as binexp unless AFS is running in which case
3417	the user is explicitly prompted for it. This variable should always
3418	be used in your makefiles for maximum portability.
3419
3420installhtml1dir (html1dir.U):
3421	This variable is really the same as html1direxp, unless you are
3422	using a different installprefix.  For extra portability, you
3423	should only use this variable within your makefiles.
3424
3425installhtml3dir (html3dir.U):
3426	This variable is really the same as html3direxp, unless you are
3427	using a different installprefix.  For extra portability, you
3428	should only use this variable within your makefiles.
3429
3430installman1dir (man1dir.U):
3431	This variable is really the same as man1direxp, unless you are using
3432	AFS in which case it points to the read/write location whereas
3433	man1direxp only points to the read-only access location. For extra
3434	portability, you should only use this variable within your makefiles.
3435
3436installman3dir (man3dir.U):
3437	This variable is really the same as man3direxp, unless you are using
3438	AFS in which case it points to the read/write location whereas
3439	man3direxp only points to the read-only access location. For extra
3440	portability, you should only use this variable within your makefiles.
3441
3442installprefix (installprefix.U):
3443	This variable holds the name of the directory below which
3444	"make install" will install the package.  For most users, this
3445	is the same as prefix.  However, it is useful for
3446	installing the software into a different (usually temporary)
3447	location after which it can be bundled up and moved somehow
3448	to the final location specified by prefix.
3449
3450installprefixexp (installprefix.U):
3451	This variable holds the full absolute path of installprefix
3452	with all ~-expansion done.
3453
3454installprivlib (privlib.U):
3455	This variable is really the same as privlibexp but may differ on
3456	those systems using AFS. For extra portability, only this variable
3457	should be used in makefiles.
3458
3459installscript (scriptdir.U):
3460	This variable is usually the same as scriptdirexp, unless you are on
3461	a system running AFS, in which case they may differ slightly. You
3462	should always use this variable within your makefiles for portability.
3463
3464installsitearch (sitearch.U):
3465	This variable is really the same as sitearchexp but may differ on
3466	those systems using AFS. For extra portability, only this variable
3467	should be used in makefiles.
3468
3469installsitebin (sitebin.U):
3470	This variable is usually the same as sitebinexp, unless you are on
3471	a system running AFS, in which case they may differ slightly. You
3472	should always use this variable within your makefiles for portability.
3473
3474installsitehtml1dir (sitehtml1dir.U):
3475	This variable is really the same as sitehtml1direxp, unless you are using
3476	AFS in which case it points to the read/write location whereas
3477	html1direxp only points to the read-only access location. For extra
3478	portability, you should only use this variable within your makefiles.
3479
3480installsitehtml3dir (sitehtml3dir.U):
3481	This variable is really the same as sitehtml3direxp, unless you are using
3482	AFS in which case it points to the read/write location whereas
3483	html3direxp only points to the read-only access location. For extra
3484	portability, you should only use this variable within your makefiles.
3485
3486installsitelib (sitelib.U):
3487	This variable is really the same as sitelibexp but may differ on
3488	those systems using AFS. For extra portability, only this variable
3489	should be used in makefiles.
3490
3491installsiteman1dir (siteman1dir.U):
3492	This variable is really the same as siteman1direxp, unless you are using
3493	AFS in which case it points to the read/write location whereas
3494	man1direxp only points to the read-only access location. For extra
3495	portability, you should only use this variable within your makefiles.
3496
3497installsiteman3dir (siteman3dir.U):
3498	This variable is really the same as siteman3direxp, unless you are using
3499	AFS in which case it points to the read/write location whereas
3500	man3direxp only points to the read-only access location. For extra
3501	portability, you should only use this variable within your makefiles.
3502
3503installsitescript (sitescript.U):
3504	This variable is usually the same as sitescriptexp, unless you are on
3505	a system running AFS, in which case they may differ slightly. You
3506	should always use this variable within your makefiles for portability.
3507
3508installstyle (installstyle.U):
3509	This variable describes the "style" of the perl installation.
3510	This is intended to be useful for tools that need to
3511	manipulate entire perl distributions.  Perl itself doesn't use
3512	this to find its libraries -- the library directories are
3513	stored directly in Config.pm.  Currently, there are only two
3514	styles:  "lib" and "lib/perl5".  The default library locations
3515	(e.g. privlib, sitelib) are either $prefix/lib or
3516	$prefix/lib/perl5.  The former is useful if $prefix is a
3517	directory dedicated to perl (e.g. /opt/perl), while the latter
3518	is useful if $prefix is shared by many packages, e.g. if
3519	$prefix=/usr/local.
3520
3521	Unfortunately, while this "style" variable is used to set
3522	defaults for all three directory hierarchies (core, vendor, and
3523	site), there is no guarantee that the same style is actually
3524	appropriate for all those directories.  For example, $prefix
3525	might be /opt/perl, but $siteprefix might be /usr/local.
3526	(Perhaps, in retrospect, the "lib" style should never have been
3527	supported, but it did seem like a nice idea at the time.)
3528
3529	The situation is even less clear for tools such as MakeMaker
3530	that can be used to install additional modules into
3531	non-standard places.  For example, if a user intends to install
3532	a module into a private directory (perhaps by setting PREFIX on
3533	the Makefile.PL command line), then there is no reason to
3534	assume that the Configure-time $installstyle setting will be
3535	relevant for that PREFIX.
3536
3537	This may later be extended to include other information, so
3538	be careful with pattern-matching on the results.
3539
3540	For compatibility with perl5.005 and earlier, the default
3541	setting is based on whether or not $prefix contains the string
3542	"perl".
3543
3544installusrbinperl (instubperl.U):
3545	This variable tells whether Perl should be installed also as
3546	/usr/bin/perl in addition to
3547	$installbin/perl
3548
3549installvendorarch (vendorarch.U):
3550	This variable is really the same as vendorarchexp but may differ on
3551	those systems using AFS. For extra portability, only this variable
3552	should be used in makefiles.
3553
3554installvendorbin (vendorbin.U):
3555	This variable is really the same as vendorbinexp but may differ on
3556	those systems using AFS. For extra portability, only this variable
3557	should be used in makefiles.
3558
3559installvendorhtml1dir (vendorhtml1dir.U):
3560	This variable is really the same as vendorhtml1direxp but may differ on
3561	those systems using AFS. For extra portability, only this variable
3562	should be used in makefiles.
3563
3564installvendorhtml3dir (vendorhtml3dir.U):
3565	This variable is really the same as vendorhtml3direxp but may differ on
3566	those systems using AFS. For extra portability, only this variable
3567	should be used in makefiles.
3568
3569installvendorlib (vendorlib.U):
3570	This variable is really the same as vendorlibexp but may differ on
3571	those systems using AFS. For extra portability, only this variable
3572	should be used in makefiles.
3573
3574installvendorman1dir (vendorman1dir.U):
3575	This variable is really the same as vendorman1direxp but may differ on
3576	those systems using AFS. For extra portability, only this variable
3577	should be used in makefiles.
3578
3579installvendorman3dir (vendorman3dir.U):
3580	This variable is really the same as vendorman3direxp but may differ on
3581	those systems using AFS. For extra portability, only this variable
3582	should be used in makefiles.
3583
3584installvendorscript (vendorscript.U):
3585	This variable is really the same as vendorscriptexp but may differ on
3586	those systems using AFS. For extra portability, only this variable
3587	should be used in makefiles.
3588
3589intsize (intsize.U):
3590	This variable contains the value of the INTSIZE symbol, which
3591	indicates to the C program how many bytes there are in an int.
3592
3593issymlink (issymlink.U):
3594	This variable holds the test command to test for a symbolic link
3595	(if they are supported).  Typical values include 'test -h' and
3596	'test -L'.
3597
3598ivdformat (perlxvf.U):
3599	This variable contains the format string used for printing
3600	a Perl IV as a signed decimal integer.
3601
3602ivsize (perlxv.U):
3603	This variable is the size of an IV in bytes.
3604
3605ivtype (perlxv.U):
3606	This variable contains the C type used for Perl's IV.
3607
3608known_extensions (Extensions.U):
3609	This variable holds a list of all XS extensions included in
3610	the package.
3611
3612ksh (Loc.U):
3613	This variable is defined but not used by Configure.
3614	The value is the empty string and is not useful.
3615
3616ld (dlsrc.U):
3617	This variable indicates the program to be used to link
3618	libraries for dynamic loading.  On some systems, it is 'ld'.
3619	On ELF systems, it should be $cc.  Mostly, we'll try to respect
3620	the hint file setting.
3621
3622ld_can_script (dlsrc.U):
3623	This variable shows if the loader accepts scripts in the form of
3624	-Wl,--version-script=ld.script. This is currently only supported
3625	for GNU ld on ELF in dynamic loading builds.
3626
3627lddlflags (dlsrc.U):
3628	This variable contains any special flags that might need to be
3629	passed to $ld to create a shared library suitable for dynamic
3630	loading.  It is up to the makefile to use it.  For hpux, it
3631	should be '-b'.  For sunos 4.1, it is empty.
3632
3633ldflags (ccflags.U):
3634	This variable contains any additional C loader flags desired by
3635	the user.  It is up to the Makefile to use this.
3636
3637ldflags_uselargefiles (uselfs.U):
3638	This variable contains the loader flags needed by large file builds
3639	and added to ldflags by hints files.
3640
3641ldlibpthname (libperl.U):
3642	This variable holds the name of the shared library
3643	search path, often LD_LIBRARY_PATH.  To get an empty
3644	string, the hints file must set this to 'none'.
3645
3646less (Loc.U):
3647	This variable is used internally by Configure to determine the
3648	full pathname (if any) of the less program.  After Configure runs,
3649	the value is reset to a plain "less" and is not useful.
3650
3651lib_ext (Unix.U):
3652	This is an old synonym for _a.
3653
3654libc (libc.U):
3655	This variable contains the location of the C library.
3656
3657libperl (libperl.U):
3658	The perl executable is obtained by linking perlmain.c with
3659	libperl, any static extensions (usually just DynaLoader),
3660	and any other libraries needed on this system.  libperl
3661	is usually libperl.a, but can also be libperl.so.xxx if
3662	the user wishes to build a perl executable with a shared
3663	library.
3664
3665libpth (libpth.U):
3666	This variable holds the general path (space-separated) used to find
3667	libraries. It is intended to be used by other units.
3668
3669libs (libs.U):
3670	This variable holds the additional libraries we want to use.
3671	It is up to the Makefile to deal with it.  The list can be empty.
3672
3673libsdirs (libs.U):
3674	This variable holds the directory names aka dirnames of the libraries
3675	we found and accepted, duplicates are removed.
3676
3677libsfiles (libs.U):
3678	This variable holds the filenames aka basenames of the libraries
3679	we found and accepted.
3680
3681libsfound (libs.U):
3682	This variable holds the full pathnames of the libraries
3683	we found and accepted.
3684
3685libspath (libs.U):
3686	This variable holds the directory names probed for libraries.
3687
3688libswanted (Myinit.U):
3689	This variable holds a list of all the libraries we want to
3690	search.  The order is chosen to pick up the c library
3691	ahead of ucb or bsd libraries for SVR4.
3692
3693libswanted_uselargefiles (uselfs.U):
3694	This variable contains the libraries needed by large file builds
3695	and added to ldflags by hints files.  It is a space separated list
3696	of the library names without the "lib" prefix or any suffix, just
3697	like libswanted..
3698
3699line (Loc.U):
3700	This variable is defined but not used by Configure.
3701	The value is the empty string and is not useful.
3702
3703lint (Loc.U):
3704	This variable is defined but not used by Configure.
3705	The value is the empty string and is not useful.
3706
3707lkflags (ccflags.U):
3708	This variable contains any additional C partial linker flags desired by
3709	the user.  It is up to the Makefile to use this.
3710
3711ln (Loc.U):
3712	This variable is used internally by Configure to determine the
3713	full pathname (if any) of the ln program.  After Configure runs,
3714	the value is reset to a plain "ln" and is not useful.
3715
3716lns (lns.U):
3717	This variable holds the name of the command to make
3718	symbolic links (if they are supported).  It can be used
3719	in the Makefile. It is either 'ln -s' or 'ln'
3720
3721localtime_r_proto (d_localtime_r.U):
3722	This variable encodes the prototype of localtime_r.
3723	It is zero if d_localtime_r is undef, and one of the
3724	REENTRANT_PROTO_T_ABC macros of reentr.h if d_localtime_r
3725	is defined.
3726
3727locincpth (ccflags.U):
3728	This variable contains a list of additional directories to be
3729	searched by the compiler.  The appropriate '-I' directives will
3730	be added to ccflags.  This is intended to simplify setting
3731	local directories from the Configure command line.
3732	It's not much, but it parallels the loclibpth stuff in libpth.U.
3733
3734loclibpth (libpth.U):
3735	This variable holds the paths (space-separated) used to find local
3736	libraries.  It is prepended to libpth, and is intended to be easily
3737	set from the command line.
3738
3739longdblsize (d_longdbl.U):
3740	This variable contains the value of the LONG_DOUBLESIZE symbol, which
3741	indicates to the C program how many bytes there are in a long double,
3742	if this system supports long doubles.
3743
3744longlongsize (d_longlong.U):
3745	This variable contains the value of the LONGLONGSIZE symbol, which
3746	indicates to the C program how many bytes there are in a long long,
3747	if this system supports long long.
3748
3749longsize (intsize.U):
3750	This variable contains the value of the LONGSIZE symbol, which
3751	indicates to the C program how many bytes there are in a long.
3752
3753lp (Loc.U):
3754	This variable is defined but not used by Configure.
3755	The value is the empty string and is not useful.
3756
3757lpr (Loc.U):
3758	This variable is defined but not used by Configure.
3759	The value is the empty string and is not useful.
3760
3761ls (Loc.U):
3762	This variable is used internally by Configure to determine the
3763	full pathname (if any) of the ls program.  After Configure runs,
3764	the value is reset to a plain "ls" and is not useful.
3765
3766lseeksize (lseektype.U):
3767	This variable defines lseektype to be something like off_t, long,
3768	or whatever type is used to declare lseek offset's type in the
3769	kernel (which also appears to be lseek's return type).
3770
3771lseektype (lseektype.U):
3772	This variable defines lseektype to be something like off_t, long,
3773	or whatever type is used to declare lseek offset's type in the
3774	kernel (which also appears to be lseek's return type).
3775
3776mad (mad.U):
3777	This variable indicates that the Misc Attribute Definition code is to
3778	be compiled.
3779
3780madlyh (mad.U):
3781	If the Misc Attribute Decoration is to be compiled, this variable is
3782	set to the name of the extra header files to be used, else it is ''
3783
3784madlyobj (mad.U):
3785	If the Misc Attribute Decoration is to be compiled, this variable is
3786	set to the name of the extra object files to be used, else it is ''
3787
3788madlysrc (mad.U):
3789	If the Misc Attribute Decoration is to be compiled, this variable is
3790	set to the name of the extra C source files to be used, else it is ''
3791
3792mail (Loc.U):
3793	This variable is defined but not used by Configure.
3794	The value is the empty string and is not useful.
3795
3796mailx (Loc.U):
3797	This variable is defined but not used by Configure.
3798	The value is the empty string and is not useful.
3799
3800make (Loc.U):
3801	This variable is used internally by Configure to determine the
3802	full pathname (if any) of the make program.  After Configure runs,
3803	the value is reset to a plain "make" and is not useful.
3804
3805make_set_make (make.U):
3806	Some versions of 'make' set the variable MAKE.  Others do not.
3807	This variable contains the string to be included in Makefile.SH
3808	so that MAKE is set if needed, and not if not needed.
3809	Possible values are:
3810
3811	make_set_make='#'		# If your make program handles this for you,
3812
3813	make_set_make="MAKE=$make"	# if it doesn't.
3814
3815	This uses a comment character so that we can distinguish a
3816	'set' value (from a previous config.sh or Configure '-D' option)
3817	from an uncomputed value.
3818
3819mallocobj (mallocsrc.U):
3820	This variable contains the name of the malloc.o that this package
3821	generates, if that malloc.o is preferred over the system malloc.
3822	Otherwise the value is null.  This variable is intended for generating
3823	Makefiles.  See mallocsrc.
3824
3825mallocsrc (mallocsrc.U):
3826	This variable contains the name of the malloc.c that comes with
3827	the package, if that malloc.c is preferred over the system malloc.
3828	Otherwise the value is null.  This variable is intended for generating
3829	Makefiles.
3830
3831malloctype (mallocsrc.U):
3832	This variable contains the kind of ptr returned by malloc and realloc.
3833
3834man1dir (man1dir.U):
3835	This variable contains the name of the directory in which manual
3836	source pages are to be put.  It is the responsibility of the
3837	Makefile.SH to get the value of this into the proper command.
3838	You must be prepared to do the ~name expansion yourself.
3839
3840man1direxp (man1dir.U):
3841	This variable is the same as the man1dir variable, but is filename
3842	expanded at configuration time, for convenient use in makefiles.
3843
3844man1ext (man1dir.U):
3845	This variable contains the extension that the manual page should
3846	have: one of 'n', 'l', or '1'.  The Makefile must supply the '.'.
3847	See man1dir.
3848
3849man3dir (man3dir.U):
3850	This variable contains the name of the directory in which manual
3851	source pages are to be put.  It is the responsibility of the
3852	Makefile.SH to get the value of this into the proper command.
3853	You must be prepared to do the ~name expansion yourself.
3854
3855man3direxp (man3dir.U):
3856	This variable is the same as the man3dir variable, but is filename
3857	expanded at configuration time, for convenient use in makefiles.
3858
3859man3ext (man3dir.U):
3860	This variable contains the extension that the manual page should
3861	have: one of 'n', 'l', or '3'.  The Makefile must supply the '.'.
3862	See man3dir.
3863
3864mips_type (usrinc.U):
3865	This variable holds the environment type for the mips system.
3866	Possible values are "BSD 4.3" and "System V".
3867
3868mistrustnm (Csym.U):
3869	This variable can be used to establish a fallthrough for the cases
3870	where nm fails to find a symbol.  If usenm is false or usenm is true
3871	and mistrustnm is false, this variable has no effect.  If usenm is true
3872	and mistrustnm is "compile", a test program will be compiled to try to
3873	find any symbol that can't be located via nm lookup.  If mistrustnm is
3874	"run", the test program will be run as well as being compiled.
3875
3876mkdir (Loc.U):
3877	This variable is used internally by Configure to determine the
3878	full pathname (if any) of the mkdir program.  After Configure runs,
3879	the value is reset to a plain "mkdir" and is not useful.
3880
3881mmaptype (d_mmap.U):
3882	This symbol contains the type of pointer returned by mmap()
3883	(and simultaneously the type of the first argument).
3884	It can be 'void *' or 'caddr_t'.
3885
3886modetype (modetype.U):
3887	This variable defines modetype to be something like mode_t,
3888	int, unsigned short, or whatever type is used to declare file
3889	modes for system calls.
3890
3891more (Loc.U):
3892	This variable is used internally by Configure to determine the
3893	full pathname (if any) of the more program.  After Configure runs,
3894	the value is reset to a plain "more" and is not useful.
3895
3896multiarch (multiarch.U):
3897	This variable conditionally defines the MULTIARCH symbol
3898	which signifies the presence of multiplatform files.
3899	This is normally set by hints files.
3900
3901mv (Loc.U):
3902	This variable is defined but not used by Configure.
3903	The value is the empty string and is not useful.
3904
3905myarchname (archname.U):
3906	This variable holds the architecture name computed by Configure in
3907	a previous run. It is not intended to be perused by any user and
3908	should never be set in a hint file.
3909
3910mydomain (myhostname.U):
3911	This variable contains the eventual value of the MYDOMAIN symbol,
3912	which is the domain of the host the program is going to run on.
3913	The domain must be appended to myhostname to form a complete host name.
3914	The dot comes with mydomain, and need not be supplied by the program.
3915
3916myhostname (myhostname.U):
3917	This variable contains the eventual value of the MYHOSTNAME symbol,
3918	which is the name of the host the program is going to run on.
3919	The domain is not kept with hostname, but must be gotten from mydomain.
3920	The dot comes with mydomain, and need not be supplied by the program.
3921
3922myuname (Oldconfig.U):
3923	The output of 'uname -a' if available, otherwise the hostname. On Xenix,
3924	pseudo variables assignments in the output are stripped, thank you. The
3925	whole thing is then lower-cased.
3926
3927n (n.U):
3928	This variable contains the '-n' flag if that is what causes the echo
3929	command to suppress newline.  Otherwise it is null.  Correct usage is
3930	$echo $n "prompt for a question: $c".
3931
3932need_va_copy (need_va_copy.U):
3933	This symbol, if defined, indicates that the system stores
3934	the variable argument list datatype, va_list, in a format
3935	that cannot be copied by simple assignment, so that some
3936	other means must be used when copying is required.
3937	As such systems vary in their provision (or non-provision)
3938	of copying mechanisms, handy.h defines a platform-
3939	independent macro, Perl_va_copy(src, dst), to do the job.
3940
3941netdb_hlen_type (netdbtype.U):
3942	This variable holds the type used for the 2nd argument to
3943	gethostbyaddr().  Usually, this is int or size_t or unsigned.
3944	This is only useful if you have gethostbyaddr(), naturally.
3945
3946netdb_host_type (netdbtype.U):
3947	This variable holds the type used for the 1st argument to
3948	gethostbyaddr().  Usually, this is char * or void *,  possibly
3949	with or without a const prefix.
3950	This is only useful if you have gethostbyaddr(), naturally.
3951
3952netdb_name_type (netdbtype.U):
3953	This variable holds the type used for the argument to
3954	gethostbyname().  Usually, this is char * or const char *.
3955	This is only useful if you have gethostbyname(), naturally.
3956
3957netdb_net_type (netdbtype.U):
3958	This variable holds the type used for the 1st argument to
3959	getnetbyaddr().  Usually, this is int or long.
3960	This is only useful if you have getnetbyaddr(), naturally.
3961
3962nm (Loc.U):
3963	This variable is used internally by Configure to determine the
3964	full pathname (if any) of the nm program.  After Configure runs,
3965	the value is reset to a plain "nm" and is not useful.
3966
3967nm_opt (usenm.U):
3968	This variable holds the options that may be necessary for nm.
3969
3970nm_so_opt (usenm.U):
3971	This variable holds the options that may be necessary for nm
3972	to work on a shared library but that can not be used on an
3973	archive library.  Currently, this is only used by Linux, where
3974	nm --dynamic is *required* to get symbols from an ELF library which
3975	has been stripped, but nm --dynamic is *fatal* on an archive library.
3976	Maybe Linux should just always set usenm=false.
3977
3978nonxs_ext (Extensions.U):
3979	This variable holds a list of all non-xs extensions included
3980	in the package.  All of them will be built.
3981
3982nroff (Loc.U):
3983	This variable is used internally by Configure to determine the
3984	full pathname (if any) of the nroff program.  After Configure runs,
3985	the value is reset to a plain "nroff" and is not useful.
3986
3987nv_overflows_integers_at (perlxv.U):
3988	This variable gives the largest integer value that NVs can hold
3989	as a constant floating point expression.
3990	If it could not be determined, it holds the value 0.
3991
3992nv_preserves_uv_bits (perlxv.U):
3993	This variable indicates how many of bits type uvtype
3994	a variable nvtype can preserve.
3995
3996nveformat (perlxvf.U):
3997	This variable contains the format string used for printing
3998	a Perl NV using %e-ish floating point format.
3999
4000nvEUformat (perlxvf.U):
4001	This variable contains the format string used for printing
4002	a Perl NV using %E-ish floating point format.
4003
4004nvfformat (perlxvf.U):
4005	This variable confains the format string used for printing
4006	a Perl NV using %f-ish floating point format.
4007
4008nvFUformat (perlxvf.U):
4009	This variable confains the format string used for printing
4010	a Perl NV using %F-ish floating point format.
4011
4012nvgformat (perlxvf.U):
4013	This variable contains the format string used for printing
4014	a Perl NV using %g-ish floating point format.
4015
4016nvGUformat (perlxvf.U):
4017	This variable contains the format string used for printing
4018	a Perl NV using %G-ish floating point format.
4019
4020nvsize (perlxv.U):
4021	This variable is the size of an NV in bytes.
4022
4023nvtype (perlxv.U):
4024	This variable contains the C type used for Perl's NV.
4025
4026o_nonblock (nblock_io.U):
4027	This variable bears the symbol value to be used during open() or fcntl()
4028	to turn on non-blocking I/O for a file descriptor. If you wish to switch
4029	between blocking and non-blocking, you may try ioctl(FIOSNBIO) instead,
4030	but that is only supported by some devices.
4031
4032obj_ext (Unix.U):
4033	This is an old synonym for _o.
4034
4035old_pthread_create_joinable (d_pthrattrj.U):
4036	This variable defines the constant to use for creating joinable
4037	(aka undetached) pthreads.  Unused if pthread.h defines
4038	PTHREAD_CREATE_JOINABLE.  If used, possible values are
4039	PTHREAD_CREATE_UNDETACHED and __UNDETACHED.
4040
4041optimize (ccflags.U):
4042	This variable contains any optimizer/debugger flag that should be used.
4043	It is up to the Makefile to use it.
4044
4045orderlib (orderlib.U):
4046	This variable is "true" if the components of libraries must be ordered
4047	(with `lorder $* | tsort`) before placing them in an archive.  Set to
4048	"false" if ranlib or ar can generate random libraries.
4049
4050osname (Oldconfig.U):
4051	This variable contains the operating system name (e.g. sunos,
4052	solaris, hpux, etc.).  It can be useful later on for setting
4053	defaults.  Any spaces are replaced with underscores.  It is set
4054	to a null string if we can't figure it out.
4055
4056osvers (Oldconfig.U):
4057	This variable contains the operating system version (e.g.
4058	4.1.3, 5.2, etc.).  It is primarily used for helping select
4059	an appropriate hints file, but might be useful elsewhere for
4060	setting defaults.  It is set to '' if we can't figure it out.
4061	We try to be flexible about how much of the version number
4062	to keep, e.g. if 4.1.1, 4.1.2, and 4.1.3 are essentially the
4063	same for this package, hints files might just be os_4.0 or
4064	os_4.1, etc., not keeping separate files for each little release.
4065
4066otherlibdirs (otherlibdirs.U):
4067	This variable contains a colon-separated set of paths for the perl
4068	binary to search for additional library files or modules.
4069	These directories will be tacked to the end of @INC.
4070	Perl will automatically search below each path for version-
4071	and architecture-specific directories.  See inc_version_list
4072	for more details.
4073	A value of ' ' means 'none' and is used to preserve this value
4074	for the next run through Configure.
4075
4076package (package.U):
4077	This variable contains the name of the package being constructed.
4078	It is primarily intended for the use of later Configure units.
4079
4080pager (pager.U):
4081	This variable contains the name of the preferred pager on the system.
4082	Usual values are (the full pathnames of) more, less, pg, or cat.
4083
4084passcat (nis.U):
4085	This variable contains a command that produces the text of the
4086	/etc/passwd file.  This is normally "cat /etc/passwd", but can be
4087	"ypcat passwd" when NIS is used.
4088	On some systems, such as os390, there may be no equivalent
4089	command, in which case this variable is unset.
4090
4091patchlevel (patchlevel.U):
4092	The patchlevel level of this package.
4093	The value of patchlevel comes from the patchlevel.h file.
4094	In a version number such as 5.6.1, this is the "6".
4095	In patchlevel.h, this is referred to as "PERL_VERSION".
4096
4097path_sep (Unix.U):
4098	This is an old synonym for p_ in Head.U, the character
4099	used to separate elements in the command shell search PATH.
4100
4101perl (Loc.U):
4102	This variable is used internally by Configure to determine the
4103	full pathname (if any) of the perl program.  After Configure runs,
4104	the value is reset to a plain "perl" and is not useful.
4105
4106perl5 (perl5.U):
4107	This variable contains the full path (if any) to a previously
4108	installed perl5.005 or later suitable for running the script
4109	to determine inc_version_list.
4110
4111PERL_API_REVISION (patchlevel.h):
4112	This number describes the earliest compatible PERL_REVISION of
4113	Perl ("compatibility" here being defined as sufficient binary/API
4114	compatibility to run XS code built with the older version).
4115	Normally this does not change across maintenance releases.
4116	Please read the comment in patchlevel.h.
4117
4118PERL_API_SUBVERSION (patchlevel.h):
4119	This number describes the earliest compatible PERL_SUBVERSION of
4120	Perl ("compatibility" here being defined as sufficient binary/API
4121	compatibility to run XS code built with the older version).
4122	Normally this does not change across maintenance releases.
4123	Please read the comment in patchlevel.h.
4124
4125PERL_API_VERSION (patchlevel.h):
4126	This number describes the earliest compatible PERL_VERSION of
4127	Perl ("compatibility" here being defined as sufficient binary/API
4128	compatibility to run XS code built with the older version).
4129	Normally this does not change across maintenance releases.
4130	Please read the comment in patchlevel.h.
4131
4132PERL_CONFIG_SH (Oldsyms.U):
4133	This is set to 'true' in config.sh so that a shell script
4134	sourcing config.sh can tell if it has been sourced already.
4135
4136PERL_PATCHLEVEL (Oldsyms.U):
4137	This symbol reflects the patchlevel, if available. Will usually
4138	come from the .patch file, which is available when the perl
4139	source tree was fetched with rsync.
4140
4141perl_patchlevel (patchlevel.U):
4142	This is the Perl patch level, a numeric change identifier,
4143	as defined by whichever source code maintenance system
4144	is used to maintain the patches; currently Perforce.
4145	It does not correlate with the Perl version numbers or
4146	the maintenance versus development dichotomy except
4147	by also being increasing.
4148
4149PERL_REVISION (Oldsyms.U):
4150	In a Perl version number such as 5.6.2, this is the 5.
4151	This value is manually set in patchlevel.h
4152
4153perl_static_inline (d_static_inline.U):
4154	This variable defines the PERL_STATIC_INLINE symbol to
4155	the best-guess incantation to use for static inline functions.
4156	Possibilities include
4157	static inline       (c99)
4158	static __inline__   (gcc -ansi)
4159	static __inline     (MSVC)
4160	static _inline      (older MSVC)
4161	static              (c89 compilers)
4162
4163PERL_SUBVERSION (Oldsyms.U):
4164	In a Perl version number such as 5.6.2, this is the 2.
4165	Values greater than 50 represent potentially unstable
4166	development subversions.
4167	This value is manually set in patchlevel.h
4168
4169PERL_VERSION (Oldsyms.U):
4170	In a Perl version number such as 5.6.2, this is the 6.
4171	This value is manually set in patchlevel.h
4172
4173perladmin (perladmin.U):
4174	Electronic mail address of the perl5 administrator.
4175
4176perllibs (End.U):
4177	The list of libraries needed by Perl only (any libraries needed
4178	by extensions only will by dropped, if using dynamic loading).
4179
4180perlpath (perlpath.U):
4181	This variable contains the eventual value of the PERLPATH symbol,
4182	which contains the name of the perl interpreter to be used in
4183	shell scripts and in the "eval 'exec'" idiom.  This variable is
4184	not necessarily the pathname of the file containing the perl
4185	interpreter; you must append the executable extension (_exe) if
4186	it is not already present.  Note that Perl code that runs during
4187	the Perl build process cannot reference this variable, as Perl
4188	may not have been installed, or even if installed, may be a
4189	different version of Perl.
4190
4191pg (Loc.U):
4192	This variable is used internally by Configure to determine the
4193	full pathname (if any) of the pg program.  After Configure runs,
4194	the value is reset to a plain "pg" and is not useful.
4195
4196phostname (myhostname.U):
4197	This variable contains the eventual value of the PHOSTNAME symbol,
4198	which is a command that can be fed to popen() to get the host name.
4199	The program should probably not presume that the domain is or isn't
4200	there already.
4201
4202pidtype (pidtype.U):
4203	This variable defines PIDTYPE to be something like pid_t, int,
4204	ushort, or whatever type is used to declare process ids in the kernel.
4205
4206plibpth (libpth.U):
4207	Holds the private path used by Configure to find out the libraries.
4208	Its value is prepend to libpth. This variable takes care of special
4209	machines, like the mips.  Usually, it should be empty.
4210
4211pmake (Loc.U):
4212	This variable is defined but not used by Configure.
4213	The value is the empty string and is not useful.
4214
4215pr (Loc.U):
4216	This variable is defined but not used by Configure.
4217	The value is the empty string and is not useful.
4218
4219prefix (prefix.U):
4220	This variable holds the name of the directory below which the
4221	user will install the package.  Usually, this is /usr/local, and
4222	executables go in /usr/local/bin, library stuff in /usr/local/lib,
4223	man pages in /usr/local/man, etc.  It is only used to set defaults
4224	for things in bin.U, mansrc.U, privlib.U, or scriptdir.U.
4225
4226prefixexp (prefix.U):
4227	This variable holds the full absolute path of the directory below
4228	which the user will install the package.  Derived from prefix.
4229
4230privlib (privlib.U):
4231	This variable contains the eventual value of the PRIVLIB symbol,
4232	which is the name of the private library for this package.  It may
4233	have a ~ on the front. It is up to the makefile to eventually create
4234	this directory while performing installation (with ~ substitution).
4235
4236privlibexp (privlib.U):
4237	This variable is the ~name expanded version of privlib, so that you
4238	may use it directly in Makefiles or shell scripts.
4239
4240procselfexe (d_procselfexe.U):
4241	If d_procselfexe is defined, $procselfexe is the filename
4242	of the symbolic link pointing to the absolute pathname of
4243	the executing program.
4244
4245prototype (prototype.U):
4246	This variable holds the eventual value of CAN_PROTOTYPE, which
4247	indicates the C compiler can handle funciton prototypes.
4248
4249ptrsize (ptrsize.U):
4250	This variable contains the value of the PTRSIZE symbol, which
4251	indicates to the C program how many bytes there are in a pointer.
4252
4253quadkind (quadtype.U):
4254	This variable, if defined, encodes the type of a quad:
4255	1 = int, 2 = long, 3 = long long, 4 = int64_t.
4256
4257quadtype (quadtype.U):
4258	This variable defines Quad_t to be something like long, int,
4259	long long, int64_t, or whatever type is used for 64-bit integers.
4260
4261randbits (randfunc.U):
4262	Indicates how many bits are produced by the function used to
4263	generate normalized random numbers.
4264
4265randfunc (randfunc.U):
4266	Indicates the name of the random number function to use.
4267	Values include drand48, random, and rand. In C programs,
4268	the 'Drand01' macro is defined to generate uniformly distributed
4269	random numbers over the range [0., 1.[ (see drand01 and nrand).
4270
4271random_r_proto (d_random_r.U):
4272	This variable encodes the prototype of random_r.
4273	It is zero if d_random_r is undef, and one of the
4274	REENTRANT_PROTO_T_ABC macros of reentr.h if d_random_r
4275	is defined.
4276
4277randseedtype (randfunc.U):
4278	Indicates the type of the argument of the seedfunc.
4279
4280ranlib (orderlib.U):
4281	This variable is set to the pathname of the ranlib program, if it is
4282	needed to generate random libraries.  Set to ":" if ar can generate
4283	random libraries or if random libraries are not supported
4284
4285rd_nodata (nblock_io.U):
4286	This variable holds the return code from read() when no data is
4287	present. It should be -1, but some systems return 0 when O_NDELAY is
4288	used, which is a shame because you cannot make the difference between
4289	no data and an EOF.. Sigh!
4290
4291readdir64_r_proto (d_readdir64_r.U):
4292	This variable encodes the prototype of readdir64_r.
4293	It is zero if d_readdir64_r is undef, and one of the
4294	REENTRANT_PROTO_T_ABC macros of reentr.h if d_readdir64_r
4295	is defined.
4296
4297readdir_r_proto (d_readdir_r.U):
4298	This variable encodes the prototype of readdir_r.
4299	It is zero if d_readdir_r is undef, and one of the
4300	REENTRANT_PROTO_T_ABC macros of reentr.h if d_readdir_r
4301	is defined.
4302
4303revision (patchlevel.U):
4304	The value of revision comes from the patchlevel.h file.
4305	In a version number such as 5.6.1, this is the "5".
4306	In patchlevel.h, this is referred to as "PERL_REVISION".
4307
4308rm (Loc.U):
4309	This variable is used internally by Configure to determine the
4310	full pathname (if any) of the rm program.  After Configure runs,
4311	the value is reset to a plain "rm" and is not useful.
4312
4313rm_try (Unix.U):
4314	This is a cleanup variable for try test programs.
4315	Internal Configure use only.
4316
4317rmail (Loc.U):
4318	This variable is defined but not used by Configure.
4319	The value is the empty string and is not useful.
4320
4321run (Cross.U):
4322	This variable contains the command used by Configure
4323	to copy and execute a cross-compiled executable in the
4324	target host.  Useful and available only during Perl build.
4325	Empty string '' if not cross-compiling.
4326
4327runnm (usenm.U):
4328	This variable contains 'true' or 'false' depending whether the
4329	nm extraction should be performed or not, according to the value
4330	of usenm and the flags on the Configure command line.
4331
4332sched_yield (d_pthread_y.U):
4333	This variable defines the way to yield the execution
4334	of the current thread.
4335
4336scriptdir (scriptdir.U):
4337	This variable holds the name of the directory in which the user wants
4338	to put publicly scripts for the package in question.  It is either
4339	the same directory as for binaries, or a special one that can be
4340	mounted across different architectures, like /usr/share. Programs
4341	must be prepared to deal with ~name expansion.
4342
4343scriptdirexp (scriptdir.U):
4344	This variable is the same as scriptdir, but is filename expanded
4345	at configuration time, for programs not wanting to bother with it.
4346
4347sed (Loc.U):
4348	This variable is used internally by Configure to determine the
4349	full pathname (if any) of the sed program.  After Configure runs,
4350	the value is reset to a plain "sed" and is not useful.
4351
4352seedfunc (randfunc.U):
4353	Indicates the random number generating seed function.
4354	Values include srand48, srandom, and srand.
4355
4356selectminbits (selectminbits.U):
4357	This variable holds the minimum number of bits operated by select.
4358	That is, if you do select(n, ...), how many bits at least will be
4359	cleared in the masks if some activity is detected.  Usually this
4360	is either n or 32*ceil(n/32), especially many little-endians do
4361	the latter.  This is only useful if you have select(), naturally.
4362
4363selecttype (selecttype.U):
4364	This variable holds the type used for the 2nd, 3rd, and 4th
4365	arguments to select.  Usually, this is 'fd_set *', if HAS_FD_SET
4366	is defined, and 'int *' otherwise.  This is only useful if you
4367	have select(), naturally.
4368
4369sendmail (Loc.U):
4370	This variable is defined but not used by Configure.
4371	The value is the empty string and is not useful.
4372
4373setgrent_r_proto (d_setgrent_r.U):
4374	This variable encodes the prototype of setgrent_r.
4375	It is zero if d_setgrent_r is undef, and one of the
4376	REENTRANT_PROTO_T_ABC macros of reentr.h if d_setgrent_r
4377	is defined.
4378
4379sethostent_r_proto (d_sethostent_r.U):
4380	This variable encodes the prototype of sethostent_r.
4381	It is zero if d_sethostent_r is undef, and one of the
4382	REENTRANT_PROTO_T_ABC macros of reentr.h if d_sethostent_r
4383	is defined.
4384
4385setlocale_r_proto (d_setlocale_r.U):
4386	This variable encodes the prototype of setlocale_r.
4387	It is zero if d_setlocale_r is undef, and one of the
4388	REENTRANT_PROTO_T_ABC macros of reentr.h if d_setlocale_r
4389	is defined.
4390
4391setnetent_r_proto (d_setnetent_r.U):
4392	This variable encodes the prototype of setnetent_r.
4393	It is zero if d_setnetent_r is undef, and one of the
4394	REENTRANT_PROTO_T_ABC macros of reentr.h if d_setnetent_r
4395	is defined.
4396
4397setprotoent_r_proto (d_setprotoent_r.U):
4398	This variable encodes the prototype of setprotoent_r.
4399	It is zero if d_setprotoent_r is undef, and one of the
4400	REENTRANT_PROTO_T_ABC macros of reentr.h if d_setprotoent_r
4401	is defined.
4402
4403setpwent_r_proto (d_setpwent_r.U):
4404	This variable encodes the prototype of setpwent_r.
4405	It is zero if d_setpwent_r is undef, and one of the
4406	REENTRANT_PROTO_T_ABC macros of reentr.h if d_setpwent_r
4407	is defined.
4408
4409setservent_r_proto (d_setservent_r.U):
4410	This variable encodes the prototype of setservent_r.
4411	It is zero if d_setservent_r is undef, and one of the
4412	REENTRANT_PROTO_T_ABC macros of reentr.h if d_setservent_r
4413	is defined.
4414
4415sGMTIME_max (time_size.U):
4416	This variable defines the maximum value of the time_t offset that
4417	the system function gmtime () accepts
4418
4419sGMTIME_min (time_size.U):
4420	This variable defines the minimum value of the time_t offset that
4421	the system function gmtime () accepts
4422
4423sh (sh.U):
4424	This variable contains the full pathname of the shell used
4425	on this system to execute Bourne shell scripts.  Usually, this will be
4426	/bin/sh, though it's possible that some systems will have /bin/ksh,
4427	/bin/pdksh, /bin/ash, /bin/bash, or even something such as
4428	D:/bin/sh.exe.
4429	This unit comes before Options.U, so you can't set sh with a '-D'
4430	option, though you can override this (and startsh)
4431	with '-O -Dsh=/bin/whatever -Dstartsh=whatever'
4432
4433shar (Loc.U):
4434	This variable is defined but not used by Configure.
4435	The value is the empty string and is not useful.
4436
4437sharpbang (spitshell.U):
4438	This variable contains the string #! if this system supports that
4439	construct.
4440
4441shmattype (d_shmat.U):
4442	This symbol contains the type of pointer returned by shmat().
4443	It can be 'void *' or 'char *'.
4444
4445shortsize (intsize.U):
4446	This variable contains the value of the SHORTSIZE symbol which
4447	indicates to the C program how many bytes there are in a short.
4448
4449shrpenv (libperl.U):
4450	If the user builds a shared libperl.so, then we need to tell the
4451	'perl' executable where it will be able to find the installed libperl.so.
4452	One way to do this on some systems is to set the environment variable
4453	LD_RUN_PATH to the directory that will be the final location of the
4454	shared libperl.so.  The makefile can use this with something like
4455	$shrpenv $(CC) -o perl perlmain.o $libperl $libs
4456	Typical values are
4457	shrpenv="env LD_RUN_PATH=$archlibexp/CORE"
4458	or
4459	shrpenv=''
4460	See the main perl Makefile.SH for actual working usage.
4461	Alternatively, we might be able to use a command line option such
4462	as -R $archlibexp/CORE (Solaris) or -Wl,-rpath
4463	$archlibexp/CORE (Linux).
4464
4465shsharp (spitshell.U):
4466	This variable tells further Configure units whether your sh can
4467	handle # comments.
4468
4469sig_count (sig_name.U):
4470	This variable holds a number larger than the largest valid
4471	signal number.  This is usually the same as the NSIG macro.
4472
4473sig_name (sig_name.U):
4474	This variable holds the signal names, space separated. The leading
4475	SIG in signal name is removed.  A ZERO is prepended to the list.
4476	This is currently not used, sig_name_init is used instead.
4477
4478sig_name_init (sig_name.U):
4479	This variable holds the signal names, enclosed in double quotes and
4480	separated by commas, suitable for use in the SIG_NAME definition
4481	below.  A "ZERO" is prepended to the list, and the list is
4482	terminated with a plain 0.  The leading SIG in signal names
4483	is removed. See sig_num.
4484
4485sig_num (sig_name.U):
4486	This variable holds the signal numbers, space separated. A ZERO is
4487	prepended to the list (corresponding to the fake SIGZERO).
4488	Those numbers correspond to  the value of the signal listed
4489	in the same place within the sig_name list.
4490	This is currently not used, sig_num_init is used instead.
4491
4492sig_num_init (sig_name.U):
4493	This variable holds the signal numbers, enclosed in double quotes and
4494	separated by commas, suitable for use in the SIG_NUM definition
4495	below.  A "ZERO" is prepended to the list, and the list is
4496	terminated with a plain 0.
4497
4498sig_size (sig_name.U):
4499	This variable contains the number of elements of the sig_name
4500	and sig_num arrays.
4501
4502signal_t (d_voidsig.U):
4503	This variable holds the type of the signal handler (void or int).
4504
4505sitearch (sitearch.U):
4506	This variable contains the eventual value of the SITEARCH symbol,
4507	which is the name of the private library for this package.  It may
4508	have a ~ on the front. It is up to the makefile to eventually create
4509	this directory while performing installation (with ~ substitution).
4510	The standard distribution will put nothing in this directory.
4511	After perl has been installed, users may install their own local
4512	architecture-dependent modules in this directory with
4513	MakeMaker Makefile.PL
4514	or equivalent.  See INSTALL for details.
4515
4516sitearchexp (sitearch.U):
4517	This variable is the ~name expanded version of sitearch, so that you
4518	may use it directly in Makefiles or shell scripts.
4519
4520sitebin (sitebin.U):
4521	This variable holds the name of the directory in which the user wants
4522	to put add-on publicly executable files for the package in question.  It
4523	is most often a local directory such as /usr/local/bin. Programs using
4524	this variable must be prepared to deal with ~name substitution.
4525	The standard distribution will put nothing in this directory.
4526	After perl has been installed, users may install their own local
4527	executables in this directory with
4528	MakeMaker Makefile.PL
4529	or equivalent.  See INSTALL for details.
4530
4531sitebinexp (sitebin.U):
4532	This is the same as the sitebin variable, but is filename expanded at
4533	configuration time, for use in your makefiles.
4534
4535sitehtml1dir (sitehtml1dir.U):
4536	This variable contains the name of the directory in which site-specific
4537	html source pages are to be put.  It is the responsibility of the
4538	Makefile.SH to get the value of this into the proper command.
4539	You must be prepared to do the ~name expansion yourself.
4540	The standard distribution will put nothing in this directory.
4541	After perl has been installed, users may install their own local
4542	html pages in this directory with
4543	MakeMaker Makefile.PL
4544	or equivalent.  See INSTALL for details.
4545
4546sitehtml1direxp (sitehtml1dir.U):
4547	This variable is the same as the sitehtml1dir variable, but is filename
4548	expanded at configuration time, for convenient use in makefiles.
4549
4550sitehtml3dir (sitehtml3dir.U):
4551	This variable contains the name of the directory in which site-specific
4552	library html source pages are to be put.  It is the responsibility of the
4553	Makefile.SH to get the value of this into the proper command.
4554	You must be prepared to do the ~name expansion yourself.
4555	The standard distribution will put nothing in this directory.
4556	After perl has been installed, users may install their own local
4557	library html pages in this directory with
4558	MakeMaker Makefile.PL
4559	or equivalent.  See INSTALL for details.
4560
4561sitehtml3direxp (sitehtml3dir.U):
4562	This variable is the same as the sitehtml3dir variable, but is filename
4563	expanded at configuration time, for convenient use in makefiles.
4564
4565sitelib (sitelib.U):
4566	This variable contains the eventual value of the SITELIB symbol,
4567	which is the name of the private library for this package.  It may
4568	have a ~ on the front. It is up to the makefile to eventually create
4569	this directory while performing installation (with ~ substitution).
4570	The standard distribution will put nothing in this directory.
4571	After perl has been installed, users may install their own local
4572	architecture-independent modules in this directory with
4573	MakeMaker Makefile.PL
4574	or equivalent.  See INSTALL for details.
4575
4576sitelib_stem (sitelib.U):
4577	This variable is $sitelibexp with any trailing version-specific component
4578	removed.  The elements in inc_version_list (inc_version_list.U) can
4579	be tacked onto this variable to generate a list of directories to search.
4580
4581sitelibexp (sitelib.U):
4582	This variable is the ~name expanded version of sitelib, so that you
4583	may use it directly in Makefiles or shell scripts.
4584
4585siteman1dir (siteman1dir.U):
4586	This variable contains the name of the directory in which site-specific
4587	manual source pages are to be put.  It is the responsibility of the
4588	Makefile.SH to get the value of this into the proper command.
4589	You must be prepared to do the ~name expansion yourself.
4590	The standard distribution will put nothing in this directory.
4591	After perl has been installed, users may install their own local
4592	man1 pages in this directory with
4593	MakeMaker Makefile.PL
4594	or equivalent.  See INSTALL for details.
4595
4596siteman1direxp (siteman1dir.U):
4597	This variable is the same as the siteman1dir variable, but is filename
4598	expanded at configuration time, for convenient use in makefiles.
4599
4600siteman3dir (siteman3dir.U):
4601	This variable contains the name of the directory in which site-specific
4602	library man source pages are to be put.  It is the responsibility of the
4603	Makefile.SH to get the value of this into the proper command.
4604	You must be prepared to do the ~name expansion yourself.
4605	The standard distribution will put nothing in this directory.
4606	After perl has been installed, users may install their own local
4607	man3 pages in this directory with
4608	MakeMaker Makefile.PL
4609	or equivalent.  See INSTALL for details.
4610
4611siteman3direxp (siteman3dir.U):
4612	This variable is the same as the siteman3dir variable, but is filename
4613	expanded at configuration time, for convenient use in makefiles.
4614
4615siteprefix (siteprefix.U):
4616	This variable holds the full absolute path of the directory below
4617	which the user will install add-on packages.
4618	See INSTALL for usage and examples.
4619
4620siteprefixexp (siteprefix.U):
4621	This variable holds the full absolute path of the directory below
4622	which the user will install add-on packages.  Derived from siteprefix.
4623
4624sitescript (sitescript.U):
4625	This variable holds the name of the directory in which the user wants
4626	to put add-on publicly executable files for the package in question.  It
4627	is most often a local directory such as /usr/local/bin. Programs using
4628	this variable must be prepared to deal with ~name substitution.
4629	The standard distribution will put nothing in this directory.
4630	After perl has been installed, users may install their own local
4631	scripts in this directory with
4632	MakeMaker Makefile.PL
4633	or equivalent.  See INSTALL for details.
4634
4635sitescriptexp (sitescript.U):
4636	This is the same as the sitescript variable, but is filename expanded at
4637	configuration time, for use in your makefiles.
4638
4639sizesize (sizesize.U):
4640	This variable contains the size of a sizetype in bytes.
4641
4642sizetype (sizetype.U):
4643	This variable defines sizetype to be something like size_t,
4644	unsigned long, or whatever type is used to declare length
4645	parameters for string functions.
4646
4647sleep (Loc.U):
4648	This variable is defined but not used by Configure.
4649	The value is the empty string and is not useful.
4650
4651sLOCALTIME_max (time_size.U):
4652	This variable defines the maximum value of the time_t offset that
4653	the system function localtime () accepts
4654
4655sLOCALTIME_min (time_size.U):
4656	This variable defines the minimum value of the time_t offset that
4657	the system function localtime () accepts
4658
4659smail (Loc.U):
4660	This variable is defined but not used by Configure.
4661	The value is the empty string and is not useful.
4662
4663so (so.U):
4664	This variable holds the extension used to identify shared libraries
4665	(also known as shared objects) on the system. Usually set to 'so'.
4666
4667sockethdr (d_socket.U):
4668	This variable has any cpp '-I' flags needed for socket support.
4669
4670socketlib (d_socket.U):
4671	This variable has the names of any libraries needed for socket support.
4672
4673socksizetype (socksizetype.U):
4674	This variable holds the type used for the size argument
4675	for various socket calls like accept.  Usual values include
4676	socklen_t, size_t, and int.
4677
4678sort (Loc.U):
4679	This variable is used internally by Configure to determine the
4680	full pathname (if any) of the sort program.  After Configure runs,
4681	the value is reset to a plain "sort" and is not useful.
4682
4683spackage (package.U):
4684	This variable contains the name of the package being constructed,
4685	with the first letter uppercased, i.e. suitable for starting
4686	sentences.
4687
4688spitshell (spitshell.U):
4689	This variable contains the command necessary to spit out a runnable
4690	shell on this system.  It is either cat or a grep '-v' for # comments.
4691
4692sPRId64 (quadfio.U):
4693	This variable, if defined, contains the string used by stdio to
4694	format 64-bit decimal numbers (format 'd') for output.
4695
4696sPRIeldbl (longdblfio.U):
4697	This variable, if defined, contains the string used by stdio to
4698	format long doubles (format 'e') for output.
4699
4700sPRIEUldbl (longdblfio.U):
4701	This variable, if defined, contains the string used by stdio to
4702	format long doubles (format 'E') for output.
4703	The 'U' in the name is to separate this from sPRIeldbl so that even
4704	case-blind systems can see the difference.
4705
4706sPRIfldbl (longdblfio.U):
4707	This variable, if defined, contains the string used by stdio to
4708	format long doubles (format 'f') for output.
4709
4710sPRIFUldbl (longdblfio.U):
4711	This variable, if defined, contains the string used by stdio to
4712	format long doubles (format 'F') for output.
4713	The 'U' in the name is to separate this from sPRIfldbl so that even
4714	case-blind systems can see the difference.
4715
4716sPRIgldbl (longdblfio.U):
4717	This variable, if defined, contains the string used by stdio to
4718	format long doubles (format 'g') for output.
4719
4720sPRIGUldbl (longdblfio.U):
4721	This variable, if defined, contains the string used by stdio to
4722	format long doubles (format 'G') for output.
4723	The 'U' in the name is to separate this from sPRIgldbl so that even
4724	case-blind systems can see the difference.
4725
4726sPRIi64 (quadfio.U):
4727	This variable, if defined, contains the string used by stdio to
4728	format 64-bit decimal numbers (format 'i') for output.
4729
4730sPRIo64 (quadfio.U):
4731	This variable, if defined, contains the string used by stdio to
4732	format 64-bit octal numbers (format 'o') for output.
4733
4734sPRIu64 (quadfio.U):
4735	This variable, if defined, contains the string used by stdio to
4736	format 64-bit unsigned decimal numbers (format 'u') for output.
4737
4738sPRIx64 (quadfio.U):
4739	This variable, if defined, contains the string used by stdio to
4740	format 64-bit hexadecimal numbers (format 'x') for output.
4741
4742sPRIXU64 (quadfio.U):
4743	This variable, if defined, contains the string used by stdio to
4744	format 64-bit hExADECimAl numbers (format 'X') for output.
4745	The 'U' in the name is to separate this from sPRIx64 so that even
4746	case-blind systems can see the difference.
4747
4748srand48_r_proto (d_srand48_r.U):
4749	This variable encodes the prototype of srand48_r.
4750	It is zero if d_srand48_r is undef, and one of the
4751	REENTRANT_PROTO_T_ABC macros of reentr.h if d_srand48_r
4752	is defined.
4753
4754srandom_r_proto (d_srandom_r.U):
4755	This variable encodes the prototype of srandom_r.
4756	It is zero if d_srandom_r is undef, and one of the
4757	REENTRANT_PROTO_T_ABC macros of reentr.h if d_srandom_r
4758	is defined.
4759
4760src (src.U):
4761	This variable holds the (possibly relative) path of the package source.
4762	It is up to the Makefile to use this variable and set VPATH accordingly
4763	to find the sources remotely.  Use $pkgsrc to have an absolute path.
4764
4765sSCNfldbl (longdblfio.U):
4766	This variable, if defined, contains the string used by stdio to
4767	format long doubles (format 'f') for input.
4768
4769ssizetype (ssizetype.U):
4770	This variable defines ssizetype to be something like ssize_t,
4771	long or int.  It is used by functions that return a count
4772	of bytes or an error condition.  It must be a signed type.
4773	We will pick a type such that sizeof(SSize_t) == sizeof(Size_t).
4774
4775st_ino_sign (st_ino_def.U):
4776	This variable contains the signedness of struct stat's st_ino.
4777	1 for unsigned, -1 for signed.
4778
4779st_ino_size (st_ino_def.U):
4780	This variable contains the size of struct stat's st_ino in bytes.
4781
4782startperl (startperl.U):
4783	This variable contains the string to put on the front of a perl
4784	script to make sure (hopefully) that it runs with perl and not some
4785	shell. Of course, that leading line must be followed by the classical
4786	perl idiom:
4787	eval 'exec perl -S $0 ${1+"$@"}'
4788	if $running_under_some_shell;
4789	to guarantee perl startup should the shell execute the script. Note
4790	that this magic incantation is not understood by csh.
4791
4792startsh (startsh.U):
4793	This variable contains the string to put on the front of a shell
4794	script to make sure (hopefully) that it runs with sh and not some
4795	other shell.
4796
4797static_ext (Extensions.U):
4798	This variable holds a list of XS extension files we want to
4799	link statically into the package.  It is used by Makefile.
4800
4801stdchar (stdchar.U):
4802	This variable conditionally defines STDCHAR to be the type of char
4803	used in stdio.h.  It has the values "unsigned char" or "char".
4804
4805stdio_base (d_stdstdio.U):
4806	This variable defines how, given a FILE pointer, fp, to access the
4807	_base field (or equivalent) of stdio.h's FILE structure.  This will
4808	be used to define the macro FILE_base(fp).
4809
4810stdio_bufsiz (d_stdstdio.U):
4811	This variable defines how, given a FILE pointer, fp, to determine
4812	the number of bytes store in the I/O buffer pointer to by the
4813	_base field (or equivalent) of stdio.h's FILE structure.  This will
4814	be used to define the macro FILE_bufsiz(fp).
4815
4816stdio_cnt (d_stdstdio.U):
4817	This variable defines how, given a FILE pointer, fp, to access the
4818	_cnt field (or equivalent) of stdio.h's FILE structure.  This will
4819	be used to define the macro FILE_cnt(fp).
4820
4821stdio_filbuf (d_stdstdio.U):
4822	This variable defines how, given a FILE pointer, fp, to tell
4823	stdio to refill its internal buffers (?).  This will
4824	be used to define the macro FILE_filbuf(fp).
4825
4826stdio_ptr (d_stdstdio.U):
4827	This variable defines how, given a FILE pointer, fp, to access the
4828	_ptr field (or equivalent) of stdio.h's FILE structure.  This will
4829	be used to define the macro FILE_ptr(fp).
4830
4831stdio_stream_array (stdio_streams.U):
4832	This variable tells the name of the array holding the stdio streams.
4833	Usual values include _iob, __iob, and __sF.
4834
4835strerror_r_proto (d_strerror_r.U):
4836	This variable encodes the prototype of strerror_r.
4837	It is zero if d_strerror_r is undef, and one of the
4838	REENTRANT_PROTO_T_ABC macros of reentr.h if d_strerror_r
4839	is defined.
4840
4841strings (i_string.U):
4842	This variable holds the full path of the string header that will be
4843	used. Typically /usr/include/string.h or /usr/include/strings.h.
4844
4845submit (Loc.U):
4846	This variable is defined but not used by Configure.
4847	The value is the empty string and is not useful.
4848
4849subversion (patchlevel.U):
4850	The subversion level of this package.
4851	The value of subversion comes from the patchlevel.h file.
4852	In a version number such as 5.6.1, this is the "1".
4853	In patchlevel.h, this is referred to as "PERL_SUBVERSION".
4854	This is unique to perl.
4855
4856sysman (sysman.U):
4857	This variable holds the place where the manual is located on this
4858	system. It is not the place where the user wants to put his manual
4859	pages. Rather it is the place where Configure may look to find manual
4860	for unix commands (section 1 of the manual usually). See mansrc.
4861
4862tail (Loc.U):
4863	This variable is defined but not used by Configure.
4864	The value is the empty string and is not useful.
4865
4866tar (Loc.U):
4867	This variable is defined but not used by Configure.
4868	The value is the empty string and is not useful.
4869
4870targetarch (Cross.U):
4871	If cross-compiling, this variable contains the target architecture.
4872	If not, this will be empty.
4873
4874tbl (Loc.U):
4875	This variable is defined but not used by Configure.
4876	The value is the empty string and is not useful.
4877
4878tee (Loc.U):
4879	This variable is defined but not used by Configure.
4880	The value is the empty string and is not useful.
4881
4882test (Loc.U):
4883	This variable is used internally by Configure to determine the
4884	full pathname (if any) of the test program.  After Configure runs,
4885	the value is reset to a plain "test" and is not useful.
4886
4887timeincl (i_time.U):
4888	This variable holds the full path of the included time header(s).
4889
4890timetype (d_time.U):
4891	This variable holds the type returned by time(). It can be long,
4892	or time_t on BSD sites (in which case <sys/types.h> should be
4893	included). Anyway, the type Time_t should be used.
4894
4895tmpnam_r_proto (d_tmpnam_r.U):
4896	This variable encodes the prototype of tmpnam_r.
4897	It is zero if d_tmpnam_r is undef, and one of the
4898	REENTRANT_PROTO_T_ABC macros of reentr.h if d_tmpnam_r
4899	is defined.
4900
4901to (Cross.U):
4902	This variable contains the command used by Configure
4903	to copy to from the target host.  Useful and available
4904	only during Perl build.
4905	The string ':' if not cross-compiling.
4906
4907touch (Loc.U):
4908	This variable is used internally by Configure to determine the
4909	full pathname (if any) of the touch program.  After Configure runs,
4910	the value is reset to a plain "touch" and is not useful.
4911
4912tr (Loc.U):
4913	This variable is used internally by Configure to determine the
4914	full pathname (if any) of the tr program.  After Configure runs,
4915	the value is reset to a plain "tr" and is not useful.
4916
4917trnl (trnl.U):
4918	This variable contains the value to be passed to the tr(1)
4919	command to transliterate a newline.  Typical values are
4920	'\012' and '\n'.  This is needed for EBCDIC systems where
4921	newline is not necessarily '\012'.
4922
4923troff (Loc.U):
4924	This variable is defined but not used by Configure.
4925	The value is the empty string and is not useful.
4926
4927ttyname_r_proto (d_ttyname_r.U):
4928	This variable encodes the prototype of ttyname_r.
4929	It is zero if d_ttyname_r is undef, and one of the
4930	REENTRANT_PROTO_T_ABC macros of reentr.h if d_ttyname_r
4931	is defined.
4932
4933u16size (perlxv.U):
4934	This variable is the size of an U16 in bytes.
4935
4936u16type (perlxv.U):
4937	This variable contains the C type used for Perl's U16.
4938
4939u32size (perlxv.U):
4940	This variable is the size of an U32 in bytes.
4941
4942u32type (perlxv.U):
4943	This variable contains the C type used for Perl's U32.
4944
4945u64size (perlxv.U):
4946	This variable is the size of an U64 in bytes.
4947
4948u64type (perlxv.U):
4949	This variable contains the C type used for Perl's U64.
4950
4951u8size (perlxv.U):
4952	This variable is the size of an U8 in bytes.
4953
4954u8type (perlxv.U):
4955	This variable contains the C type used for Perl's U8.
4956
4957uidformat (uidf.U):
4958	This variable contains the format string used for printing a Uid_t.
4959
4960uidsign (uidsign.U):
4961	This variable contains the signedness of a uidtype.
4962	1 for unsigned, -1 for signed.
4963
4964uidsize (uidsize.U):
4965	This variable contains the size of a uidtype in bytes.
4966
4967uidtype (uidtype.U):
4968	This variable defines Uid_t to be something like uid_t, int,
4969	ushort, or whatever type is used to declare user ids in the kernel.
4970
4971uname (Loc.U):
4972	This variable is used internally by Configure to determine the
4973	full pathname (if any) of the uname program.  After Configure runs,
4974	the value is reset to a plain "uname" and is not useful.
4975
4976uniq (Loc.U):
4977	This variable is used internally by Configure to determine the
4978	full pathname (if any) of the uniq program.  After Configure runs,
4979	the value is reset to a plain "uniq" and is not useful.
4980
4981uquadtype (quadtype.U):
4982	This variable defines Uquad_t to be something like unsigned long,
4983	unsigned int, unsigned long long, uint64_t, or whatever type is
4984	used for 64-bit integers.
4985
4986use5005threads (usethreads.U):
4987	This variable conditionally defines the USE_5005THREADS symbol,
4988	and indicates that Perl should be built to use the 5.005-based
4989	threading implementation. Only valid up to 5.8.x.
4990
4991use64bitall (use64bits.U):
4992	This variable conditionally defines the USE_64_BIT_ALL symbol,
4993	and indicates that 64-bit integer types should be used
4994	when available.  The maximal possible
4995	64-bitness is employed: LP64 or ILP64, meaning that you will
4996	be able to use more than 2 gigabytes of memory.  This mode is
4997	even more binary incompatible than USE_64_BIT_INT. You may not
4998	be able to run the resulting executable in a 32-bit CPU at all or
4999	you may need at least to reboot your OS to 64-bit mode.
5000
5001use64bitint (use64bits.U):
5002	This variable conditionally defines the USE_64_BIT_INT symbol,
5003	and indicates that 64-bit integer types should be used
5004	when available.  The minimal possible 64-bitness
5005	is employed, just enough to get 64-bit integers into Perl.
5006	This may mean using for example "long longs", while your memory
5007	may still be limited to 2 gigabytes.
5008
5009usecrosscompile (Cross.U):
5010	This variable conditionally defines the USE_CROSS_COMPILE symbol,
5011	and indicates that Perl has been cross-compiled.
5012
5013usedevel (Devel.U):
5014	This variable indicates that Perl was configured with development
5015	features enabled.  This should not be done for production builds.
5016
5017usedl (dlsrc.U):
5018	This variable indicates if the system supports dynamic
5019	loading of some sort.  See also dlsrc and dlobj.
5020
5021usedtrace (usedtrace.U):
5022	This variable indicates whether we are compiling with dtrace
5023	support. See also dtrace.
5024
5025usefaststdio (usefaststdio.U):
5026	This variable conditionally defines the USE_FAST_STDIO symbol,
5027	and indicates that Perl should be built to use 'fast stdio'.
5028	Defaults to define in Perls 5.8 and earlier, to undef later.
5029
5030useithreads (usethreads.U):
5031	This variable conditionally defines the USE_ITHREADS symbol,
5032	and indicates that Perl should be built to use the interpreter-based
5033	threading implementation.
5034
5035usekernprocpathname (usekernprocpathname.U):
5036	This variable, indicates that we can use sysctl with
5037	KERN_PROC_PATHNAME to get a full path for the executable, and hence
5038	convert $^X to an absolute path.
5039
5040uselargefiles (uselfs.U):
5041	This variable conditionally defines the USE_LARGE_FILES symbol,
5042	and indicates that large file interfaces should be used when
5043	available.
5044
5045uselongdouble (uselongdbl.U):
5046	This variable conditionally defines the USE_LONG_DOUBLE symbol,
5047	and indicates that long doubles should be used when available.
5048
5049usemallocwrap (mallocsrc.U):
5050	This variable contains y if we are wrapping malloc to prevent
5051	integer overflow during size calculations.
5052
5053usemorebits (usemorebits.U):
5054	This variable conditionally defines the USE_MORE_BITS symbol,
5055	and indicates that explicit 64-bit interfaces and long doubles
5056	should be used when available.
5057
5058usemultiplicity (usemultiplicity.U):
5059	This variable conditionally defines the MULTIPLICITY symbol,
5060	and indicates that Perl should be built to use multiplicity.
5061
5062usemymalloc (mallocsrc.U):
5063	This variable contains y if the malloc that comes with this package
5064	is desired over the system's version of malloc.  People often include
5065	special versions of malloc for efficiency, but such versions are often
5066	less portable.  See also mallocsrc and mallocobj.
5067	If this is 'y', then -lmalloc is removed from $libs.
5068
5069usenm (usenm.U):
5070	This variable contains 'true' or 'false' depending whether the
5071	nm extraction is wanted or not.
5072
5073usensgetexecutablepath (usensgetexecutablepath.U):
5074	This symbol, if defined, indicates that we can use _NSGetExecutablePath
5075	and realpath to get a full path for the executable, and hence convert
5076	$^X to an absolute path.
5077
5078useopcode (Extensions.U):
5079	This variable holds either 'true' or 'false' to indicate
5080	whether the Opcode extension should be used.  The sole
5081	use for this currently is to allow an easy mechanism
5082	for users to skip the Opcode extension from the Configure
5083	command line.
5084
5085useperlio (useperlio.U):
5086	This variable conditionally defines the USE_PERLIO symbol,
5087	and indicates that the PerlIO abstraction should be
5088	used throughout.
5089
5090useposix (Extensions.U):
5091	This variable holds either 'true' or 'false' to indicate
5092	whether the POSIX extension should be used.  The sole
5093	use for this currently is to allow an easy mechanism
5094	for hints files to indicate that POSIX will not compile
5095	on a particular system.
5096
5097usereentrant (usethreads.U):
5098	This variable conditionally defines the USE_REENTRANT_API symbol,
5099	which indicates that the thread code may try to use the various
5100	_r versions of library functions.  This is only potentially
5101	meaningful if usethreads is set and is very experimental, it is
5102	not even prompted for.
5103
5104userelocatableinc (bin.U):
5105	This variable is set to true to indicate that perl should relocate
5106	@INC entries at runtime based on the path to the perl binary.
5107	Any @INC paths starting ".../" are relocated relative to the directory
5108	containing the perl binary, and a logical cleanup of the path is then
5109	made around the join point (removing "dir/../" pairs)
5110
5111usesfio (d_sfio.U):
5112	This variable is set to true when the user agrees to use sfio.
5113	It is set to false when sfio is not available or when the user
5114	explicitly requests not to use sfio.  It is here primarily so
5115	that command-line settings can override the auto-detection of
5116	d_sfio without running into a "WHOA THERE".
5117
5118useshrplib (libperl.U):
5119	This variable is set to 'true' if the user wishes
5120	to build a shared libperl, and 'false' otherwise.
5121
5122usesitecustomize (d_sitecustomize.U):
5123	This variable is set to true when the user requires a mechanism that
5124	allows the sysadmin to add entries to @INC at runtime.  This variable
5125	being set, makes perl run '$sitelib/sitecustomize.pl' at startup.
5126
5127usesocks (usesocks.U):
5128	This variable conditionally defines the USE_SOCKS symbol,
5129	and indicates that Perl should be built to use SOCKS.
5130
5131usethreads (usethreads.U):
5132	This variable conditionally defines the USE_THREADS symbol,
5133	and indicates that Perl should be built to use threads.
5134
5135usevendorprefix (vendorprefix.U):
5136	This variable tells whether the vendorprefix
5137	and consequently other vendor* paths are in use.
5138
5139usevfork (d_vfork.U):
5140	This variable is set to true when the user accepts to use vfork.
5141	It is set to false when no vfork is available or when the user
5142	explicitly requests not to use vfork.
5143
5144usrinc (usrinc.U):
5145	This variable holds the path of the include files, which is
5146	usually /usr/include. It is mainly used by other Configure units.
5147
5148uuname (Loc.U):
5149	This variable is defined but not used by Configure.
5150	The value is the empty string and is not useful.
5151
5152uvoformat (perlxvf.U):
5153	This variable contains the format string used for printing
5154	a Perl UV as an unsigned octal integer.
5155
5156uvsize (perlxv.U):
5157	This variable is the size of a UV in bytes.
5158
5159uvtype (perlxv.U):
5160	This variable contains the C type used for Perl's UV.
5161
5162uvuformat (perlxvf.U):
5163	This variable contains the format string used for printing
5164	a Perl UV as an unsigned decimal integer.
5165
5166uvxformat (perlxvf.U):
5167	This variable contains the format string used for printing
5168	a Perl UV as an unsigned hexadecimal integer in lowercase abcdef.
5169
5170uvXUformat (perlxvf.U):
5171	This variable contains the format string used for printing
5172	a Perl UV as an unsigned hexadecimal integer in uppercase ABCDEF.
5173
5174vaproto (vaproto.U):
5175	This variable conditionally defines CAN_VAPROTO on systems supporting
5176	prototype declaration of functions with a variable number of
5177	arguments. See also prototype.
5178
5179vendorarch (vendorarch.U):
5180	This variable contains the value of the PERL_VENDORARCH symbol.
5181	It may have a ~ on the front.
5182	The standard distribution will put nothing in this directory.
5183	Vendors who distribute perl may wish to place their own
5184	architecture-dependent modules and extensions in this directory with
5185	MakeMaker Makefile.PL INSTALLDIRS=vendor
5186	or equivalent.  See INSTALL for details.
5187
5188vendorarchexp (vendorarch.U):
5189	This variable is the ~name expanded version of vendorarch, so that you
5190	may use it directly in Makefiles or shell scripts.
5191
5192vendorbin (vendorbin.U):
5193	This variable contains the eventual value of the VENDORBIN symbol.
5194	It may have a ~ on the front.
5195	The standard distribution will put nothing in this directory.
5196	Vendors who distribute perl may wish to place additional
5197	binaries in this directory with
5198	MakeMaker Makefile.PL INSTALLDIRS=vendor
5199	or equivalent.  See INSTALL for details.
5200
5201vendorbinexp (vendorbin.U):
5202	This variable is the ~name expanded version of vendorbin, so that you
5203	may use it directly in Makefiles or shell scripts.
5204
5205vendorhtml1dir (vendorhtml1dir.U):
5206	This variable contains the name of the directory for html
5207	pages.  It may have a ~ on the front.
5208	The standard distribution will put nothing in this directory.
5209	Vendors who distribute perl may wish to place their own
5210	html pages in this directory with
5211	MakeMaker Makefile.PL INSTALLDIRS=vendor
5212	or equivalent.  See INSTALL for details.
5213
5214vendorhtml1direxp (vendorhtml1dir.U):
5215	This variable is the ~name expanded version of vendorhtml1dir, so that you
5216	may use it directly in Makefiles or shell scripts.
5217
5218vendorhtml3dir (vendorhtml3dir.U):
5219	This variable contains the name of the directory for html
5220	library pages.  It may have a ~ on the front.
5221	The standard distribution will put nothing in this directory.
5222	Vendors who distribute perl may wish to place their own
5223	html pages for modules and extensions in this directory with
5224	MakeMaker Makefile.PL INSTALLDIRS=vendor
5225	or equivalent.  See INSTALL for details.
5226
5227vendorhtml3direxp (vendorhtml3dir.U):
5228	This variable is the ~name expanded version of vendorhtml3dir, so that you
5229	may use it directly in Makefiles or shell scripts.
5230
5231vendorlib (vendorlib.U):
5232	This variable contains the eventual value of the VENDORLIB symbol,
5233	which is the name of the private library for this package.
5234	The standard distribution will put nothing in this directory.
5235	Vendors who distribute perl may wish to place their own
5236	modules in this directory with
5237	MakeMaker Makefile.PL INSTALLDIRS=vendor
5238	or equivalent.  See INSTALL for details.
5239
5240vendorlib_stem (vendorlib.U):
5241	This variable is $vendorlibexp with any trailing version-specific component
5242	removed.  The elements in inc_version_list (inc_version_list.U) can
5243	be tacked onto this variable to generate a list of directories to search.
5244
5245vendorlibexp (vendorlib.U):
5246	This variable is the ~name expanded version of vendorlib, so that you
5247	may use it directly in Makefiles or shell scripts.
5248
5249vendorman1dir (vendorman1dir.U):
5250	This variable contains the name of the directory for man1
5251	pages.  It may have a ~ on the front.
5252	The standard distribution will put nothing in this directory.
5253	Vendors who distribute perl may wish to place their own
5254	man1 pages in this directory with
5255	MakeMaker Makefile.PL INSTALLDIRS=vendor
5256	or equivalent.  See INSTALL for details.
5257
5258vendorman1direxp (vendorman1dir.U):
5259	This variable is the ~name expanded version of vendorman1dir, so that you
5260	may use it directly in Makefiles or shell scripts.
5261
5262vendorman3dir (vendorman3dir.U):
5263	This variable contains the name of the directory for man3
5264	pages.  It may have a ~ on the front.
5265	The standard distribution will put nothing in this directory.
5266	Vendors who distribute perl may wish to place their own
5267	man3 pages in this directory with
5268	MakeMaker Makefile.PL INSTALLDIRS=vendor
5269	or equivalent.  See INSTALL for details.
5270
5271vendorman3direxp (vendorman3dir.U):
5272	This variable is the ~name expanded version of vendorman3dir, so that you
5273	may use it directly in Makefiles or shell scripts.
5274
5275vendorprefix (vendorprefix.U):
5276	This variable holds the full absolute path of the directory below
5277	which the vendor will install add-on packages.
5278	See INSTALL for usage and examples.
5279
5280vendorprefixexp (vendorprefix.U):
5281	This variable holds the full absolute path of the directory below
5282	which the vendor will install add-on packages.  Derived from vendorprefix.
5283
5284vendorscript (vendorscript.U):
5285	This variable contains the eventual value of the VENDORSCRIPT symbol.
5286	It may have a ~ on the front.
5287	The standard distribution will put nothing in this directory.
5288	Vendors who distribute perl may wish to place additional
5289	executable scripts in this directory with
5290	MakeMaker Makefile.PL INSTALLDIRS=vendor
5291	or equivalent.  See INSTALL for details.
5292
5293vendorscriptexp (vendorscript.U):
5294	This variable is the ~name expanded version of vendorscript, so that you
5295	may use it directly in Makefiles or shell scripts.
5296
5297version (patchlevel.U):
5298	The full version number of this package, such as 5.6.1 (or 5_6_1).
5299	This combines revision, patchlevel, and subversion to get the
5300	full version number, including any possible subversions.
5301	This is suitable for use as a directory name, and hence is
5302	filesystem dependent.
5303
5304version_patchlevel_string (patchlevel.U):
5305	This is a string combining version, subversion and
5306	perl_patchlevel (if perl_patchlevel is non-zero).
5307	It is typically something like
5308	'version 7 subversion 1'  or
5309	'version 7 subversion 1 patchlevel 11224'
5310	It is computed here to avoid duplication of code in myconfig.SH
5311	and lib/Config.pm.
5312
5313versiononly (versiononly.U):
5314	If set, this symbol indicates that only the version-specific
5315	components of a perl installation should be installed.
5316	This may be useful for making a test installation of a new
5317	version without disturbing the existing installation.
5318	Setting versiononly is equivalent to setting installperl's -v option.
5319	In particular, the non-versioned scripts and programs such as
5320	a2p, c2ph, h2xs, pod2*, and perldoc are not installed
5321	(see INSTALL for a more complete list).  Nor are the man
5322	pages installed.
5323	Usually, this is undef.
5324
5325vi (Loc.U):
5326	This variable is defined but not used by Configure.
5327	The value is the empty string and is not useful.
5328
5329voidflags (voidflags.U):
5330	This variable contains the eventual value of the VOIDFLAGS symbol,
5331	which indicates how much support of the void type is given by this
5332	compiler.  See VOIDFLAGS for more info.
5333
5334xlibpth (libpth.U):
5335	This variable holds extra path (space-separated) used to find
5336	libraries on this platform, for example CPU-specific libraries
5337	(on multi-CPU platforms) may be listed here.
5338
5339yacc (yacc.U):
5340	This variable holds the name of the compiler compiler we
5341	want to use in the Makefile. It can be yacc, byacc, or bison -y.
5342
5343yaccflags (yacc.U):
5344	This variable contains any additional yacc flags desired by the
5345	user.  It is up to the Makefile to use this.
5346
5347zcat (Loc.U):
5348	This variable is defined but not used by Configure.
5349	The value is the empty string and is not useful.
5350
5351zip (Loc.U):
5352	This variable is used internally by Configure to determine the
5353	full pathname (if any) of the zip program.  After Configure runs,
5354	the value is reset to a plain "zip" and is not useful.
5355
5356