xref: /netbsd-src/external/gpl3/binutils/dist/libiberty/functions.texi (revision c5e820cae412164fcbee52f470436200af5358ea)
1@c Automatically generated from *.c and others (the comments before
2@c each entry tell you which file and where in that file).  DO NOT EDIT!
3@c Edit the *.c files, configure with --enable-maintainer-mode,
4@c run 'make stamp-functions' and gather-docs will build a new copy.
5
6@c splay-tree.c:277
7@defvr Extension HOST_CHARSET
8This macro indicates the basic character set and encoding used by the
9host: more precisely, the encoding used for character constants in
10preprocessor @samp{#if} statements (the C "execution character set").
11It is defined by @file{safe-ctype.h}, and will be an integer constant
12with one of the following values:
13
14@ftable @code
15@item HOST_CHARSET_UNKNOWN
16The host character set is unknown - that is, not one of the next two
17possibilities.
18
19@item HOST_CHARSET_ASCII
20The host character set is ASCII.
21
22@item HOST_CHARSET_EBCDIC
23The host character set is some variant of EBCDIC.  (Only one of the
24nineteen EBCDIC varying characters is tested; exercise caution.)
25@end ftable
26@end defvr
27@deftypefn Supplemental splay_tree splay_tree_new_with_typed_alloc
28(splay_tree_compare_fn @var{compare_fn},
29splay_tree_delete_key_fn @var{delete_key_fn},
30splay_tree_delete_value_fn @var{delete_value_fn},
31splay_tree_allocate_fn @var{tree_allocate_fn},
32splay_tree_allocate_fn @var{node_allocate_fn},
33splay_tree_deallocate_fn @var{deallocate_fn},
34void * @var{allocate_data})
35
36This function creates a splay tree that uses two different allocators
37@var{tree_allocate_fn} and @var{node_allocate_fn} to use for allocating the
38tree itself and its nodes respectively.  This is useful when variables of
39different types need to be allocated with different allocators.
40
41The splay tree will use @var{compare_fn} to compare nodes,
42@var{delete_key_fn} to deallocate keys, and @var{delete_value_fn} to
43deallocate values.
44
45@end deftypefn
46
47@c alloca.c:26
48@deftypefn Replacement void* alloca (size_t @var{size})
49
50This function allocates memory which will be automatically reclaimed
51after the procedure exits.  The @libib{} implementation does not free
52the memory immediately but will do so eventually during subsequent
53calls to this function.  Memory is allocated using @code{xmalloc} under
54normal circumstances.
55
56The header file @file{alloca-conf.h} can be used in conjunction with the
57GNU Autoconf test @code{AC_FUNC_ALLOCA} to test for and properly make
58available this function.  The @code{AC_FUNC_ALLOCA} test requires that
59client code use a block of preprocessor code to be safe (see the Autoconf
60manual for more); this header incorporates that logic and more, including
61the possibility of a GCC built-in function.
62
63@end deftypefn
64
65@c asprintf.c:32
66@deftypefn Extension int asprintf (char **@var{resptr}, const char *@var{format}, ...)
67
68Like @code{sprintf}, but instead of passing a pointer to a buffer, you
69pass a pointer to a pointer.  This function will compute the size of
70the buffer needed, allocate memory with @code{malloc}, and store a
71pointer to the allocated memory in @code{*@var{resptr}}.  The value
72returned is the same as @code{sprintf} would return.  If memory could
73not be allocated, minus one is returned and @code{NULL} is stored in
74@code{*@var{resptr}}.
75
76@end deftypefn
77
78@c atexit.c:6
79@deftypefn Supplemental int atexit (void (*@var{f})())
80
81Causes function @var{f} to be called at exit.  Returns 0.
82
83@end deftypefn
84
85@c basename.c:6
86@deftypefn Supplemental char* basename (const char *@var{name})
87
88Returns a pointer to the last component of pathname @var{name}.
89Behavior is undefined if the pathname ends in a directory separator.
90
91@end deftypefn
92
93@c bcmp.c:6
94@deftypefn Supplemental int bcmp (char *@var{x}, char *@var{y}, int @var{count})
95
96Compares the first @var{count} bytes of two areas of memory.  Returns
97zero if they are the same, nonzero otherwise.  Returns zero if
98@var{count} is zero.  A nonzero result only indicates a difference,
99it does not indicate any sorting order (say, by having a positive
100result mean @var{x} sorts before @var{y}).
101
102@end deftypefn
103
104@c bcopy.c:3
105@deftypefn Supplemental void bcopy (char *@var{in}, char *@var{out}, int @var{length})
106
107Copies @var{length} bytes from memory region @var{in} to region
108@var{out}.  The use of @code{bcopy} is deprecated in new programs.
109
110@end deftypefn
111
112@c bsearch.c:33
113@deftypefn Supplemental void* bsearch (const void *@var{key}, const void *@var{base}, size_t @var{nmemb}, size_t @var{size}, int (*@var{compar})(const void *, const void *))
114
115Performs a search over an array of @var{nmemb} elements pointed to by
116@var{base} for a member that matches the object pointed to by @var{key}.
117The size of each member is specified by @var{size}.  The array contents
118should be sorted in ascending order according to the @var{compar}
119comparison function.  This routine should take two arguments pointing to
120the @var{key} and to an array member, in that order, and should return an
121integer less than, equal to, or greater than zero if the @var{key} object
122is respectively less than, matching, or greater than the array member.
123
124@end deftypefn
125
126@c argv.c:142
127@deftypefn Extension char** buildargv (char *@var{sp})
128
129Given a pointer to a string, parse the string extracting fields
130separated by whitespace and optionally enclosed within either single
131or double quotes (which are stripped off), and build a vector of
132pointers to copies of the string for each field.  The input string
133remains unchanged.  The last element of the vector is followed by a
134@code{NULL} element.
135
136All of the memory for the pointer array and copies of the string
137is obtained from @code{malloc}.  All of the memory can be returned to the
138system with the single function call @code{freeargv}, which takes the
139returned result of @code{buildargv}, as it's argument.
140
141Returns a pointer to the argument vector if successful.  Returns
142@code{NULL} if @var{sp} is @code{NULL} or if there is insufficient
143memory to complete building the argument vector.
144
145If the input is a null string (as opposed to a @code{NULL} pointer),
146then buildarg returns an argument vector that has one arg, a null
147string.
148
149@end deftypefn
150
151@c bzero.c:6
152@deftypefn Supplemental void bzero (char *@var{mem}, int @var{count})
153
154Zeros @var{count} bytes starting at @var{mem}.  Use of this function
155is deprecated in favor of @code{memset}.
156
157@end deftypefn
158
159@c calloc.c:6
160@deftypefn Supplemental void* calloc (size_t @var{nelem}, size_t @var{elsize})
161
162Uses @code{malloc} to allocate storage for @var{nelem} objects of
163@var{elsize} bytes each, then zeros the memory.
164
165@end deftypefn
166
167@c choose-temp.c:46
168@deftypefn Extension char* choose_temp_base (void)
169
170Return a prefix for temporary file names or @code{NULL} if unable to
171find one.  The current directory is chosen if all else fails so the
172program is exited if a temporary directory can't be found (@code{mktemp}
173fails).  The buffer for the result is obtained with @code{xmalloc}.
174
175This function is provided for backwards compatibility only.  Its use is
176not recommended.
177
178@end deftypefn
179
180@c make-temp-file.c:95
181@deftypefn Replacement char* choose_tmpdir ()
182
183Returns a pointer to a directory path suitable for creating temporary
184files in.
185
186@end deftypefn
187
188@c clock.c:27
189@deftypefn Supplemental long clock (void)
190
191Returns an approximation of the CPU time used by the process as a
192@code{clock_t}; divide this number by @samp{CLOCKS_PER_SEC} to get the
193number of seconds used.
194
195@end deftypefn
196
197@c concat.c:24
198@deftypefn Extension char* concat (const char *@var{s1}, const char *@var{s2}, @dots{}, @code{NULL})
199
200Concatenate zero or more of strings and return the result in freshly
201@code{xmalloc}ed memory.  Returns @code{NULL} if insufficient memory is
202available.  The argument list is terminated by the first @code{NULL}
203pointer encountered.  Pointers to empty strings are ignored.
204
205@end deftypefn
206
207@c crc32.c:141
208@deftypefn Extension unsigned int crc32 (const unsigned char *@var{buf}, int @var{len}, unsigned int @var{init})
209
210Compute the 32-bit CRC of @var{buf} which has length @var{len}.  The
211starting value is @var{init}; this may be used to compute the CRC of
212data split across multiple buffers by passing the return value of each
213call as the @var{init} parameter of the next.
214
215This is intended to match the CRC used by the @command{gdb} remote
216protocol for the @samp{qCRC} command.  In order to get the same
217results as gdb for a block of data, you must pass the first CRC
218parameter as @code{0xffffffff}.
219
220This CRC can be specified as:
221
222  Width  : 32
223  Poly   : 0x04c11db7
224  Init   : parameter, typically 0xffffffff
225  RefIn  : false
226  RefOut : false
227  XorOut : 0
228
229This differs from the "standard" CRC-32 algorithm in that the values
230are not reflected, and there is no final XOR value.  These differences
231make it easy to compose the values of multiple blocks.
232
233@end deftypefn
234
235@c argv.c:52
236@deftypefn Extension char** dupargv (char **@var{vector})
237
238Duplicate an argument vector.  Simply scans through @var{vector},
239duplicating each argument until the terminating @code{NULL} is found.
240Returns a pointer to the argument vector if successful.  Returns
241@code{NULL} if there is insufficient memory to complete building the
242argument vector.
243
244@end deftypefn
245
246@c strerror.c:567
247@deftypefn Extension int errno_max (void)
248
249Returns the maximum @code{errno} value for which a corresponding
250symbolic name or message is available.  Note that in the case where we
251use the @code{sys_errlist} supplied by the system, it is possible for
252there to be more symbolic names than messages, or vice versa.  In
253fact, the manual page for @code{perror(3C)} explicitly warns that one
254should check the size of the table (@code{sys_nerr}) before indexing
255it, since new error codes may be added to the system before they are
256added to the table.  Thus @code{sys_nerr} might be smaller than value
257implied by the largest @code{errno} value defined in @code{<errno.h>}.
258
259We return the maximum value that can be used to obtain a meaningful
260symbolic name or message.
261
262@end deftypefn
263
264@c argv.c:361
265@deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp})
266
267The @var{argcp} and @code{argvp} arguments are pointers to the usual
268@code{argc} and @code{argv} arguments to @code{main}.  This function
269looks for arguments that begin with the character @samp{@@}.  Any such
270arguments are interpreted as ``response files''.  The contents of the
271response file are interpreted as additional command line options.  In
272particular, the file is separated into whitespace-separated strings;
273each such string is taken as a command-line option.  The new options
274are inserted in place of the option naming the response file, and
275@code{*argcp} and @code{*argvp} will be updated.  If the value of
276@code{*argvp} is modified by this function, then the new value has
277been dynamically allocated and can be deallocated by the caller with
278@code{freeargv}.  However, most callers will simply call
279@code{expandargv} near the beginning of @code{main} and allow the
280operating system to free the memory when the program exits.
281
282@end deftypefn
283
284@c fdmatch.c:23
285@deftypefn Extension int fdmatch (int @var{fd1}, int @var{fd2})
286
287Check to see if two open file descriptors refer to the same file.
288This is useful, for example, when we have an open file descriptor for
289an unnamed file, and the name of a file that we believe to correspond
290to that fd.  This can happen when we are exec'd with an already open
291file (@code{stdout} for example) or from the SVR4 @file{/proc} calls
292that return open file descriptors for mapped address spaces.  All we
293have to do is open the file by name and check the two file descriptors
294for a match, which is done by comparing major and minor device numbers
295and inode numbers.
296
297@end deftypefn
298
299@c fopen_unlocked.c:48
300@deftypefn Extension {FILE *} fdopen_unlocked (int @var{fildes}, const char * @var{mode})
301
302Opens and returns a @code{FILE} pointer via @code{fdopen}.  If the
303operating system supports it, ensure that the stream is setup to avoid
304any multi-threaded locking.  Otherwise return the @code{FILE} pointer
305unchanged.
306
307@end deftypefn
308
309@c ffs.c:3
310@deftypefn Supplemental int ffs (int @var{valu})
311
312Find the first (least significant) bit set in @var{valu}.  Bits are
313numbered from right to left, starting with bit 1 (corresponding to the
314value 1).  If @var{valu} is zero, zero is returned.
315
316@end deftypefn
317
318@c filename_cmp.c:32
319@deftypefn Extension int filename_cmp (const char *@var{s1}, const char *@var{s2})
320
321Return zero if the two file names @var{s1} and @var{s2} are equivalent.
322If not equivalent, the returned value is similar to what @code{strcmp}
323would return.  In other words, it returns a negative value if @var{s1}
324is less than @var{s2}, or a positive value if @var{s2} is greater than
325@var{s2}.
326
327This function does not normalize file names.  As a result, this function
328will treat filenames that are spelled differently as different even in
329the case when the two filenames point to the same underlying file.
330However, it does handle the fact that on DOS-like file systems, forward
331and backward slashes are equal.
332
333@end deftypefn
334
335@c fnmatch.txh:1
336@deftypefn Replacement int fnmatch (const char *@var{pattern}, const char *@var{string}, int @var{flags})
337
338Matches @var{string} against @var{pattern}, returning zero if it
339matches, @code{FNM_NOMATCH} if not.  @var{pattern} may contain the
340wildcards @code{?} to match any one character, @code{*} to match any
341zero or more characters, or a set of alternate characters in square
342brackets, like @samp{[a-gt8]}, which match one character (@code{a}
343through @code{g}, or @code{t}, or @code{8}, in this example) if that one
344character is in the set.  A set may be inverted (i.e., match anything
345except what's in the set) by giving @code{^} or @code{!} as the first
346character in the set.  To include those characters in the set, list them
347as anything other than the first character of the set.  To include a
348dash in the set, list it last in the set.  A backslash character makes
349the following character not special, so for example you could match
350against a literal asterisk with @samp{\*}.  To match a literal
351backslash, use @samp{\\}.
352
353@code{flags} controls various aspects of the matching process, and is a
354boolean OR of zero or more of the following values (defined in
355@code{<fnmatch.h>}):
356
357@table @code
358
359@item FNM_PATHNAME
360@itemx FNM_FILE_NAME
361@var{string} is assumed to be a path name.  No wildcard will ever match
362@code{/}.
363
364@item FNM_NOESCAPE
365Do not interpret backslashes as quoting the following special character.
366
367@item FNM_PERIOD
368A leading period (at the beginning of @var{string}, or if
369@code{FNM_PATHNAME} after a slash) is not matched by @code{*} or
370@code{?} but must be matched explicitly.
371
372@item FNM_LEADING_DIR
373Means that @var{string} also matches @var{pattern} if some initial part
374of @var{string} matches, and is followed by @code{/} and zero or more
375characters.  For example, @samp{foo*} would match either @samp{foobar}
376or @samp{foobar/grill}.
377
378@item FNM_CASEFOLD
379Ignores case when performing the comparison.
380
381@end table
382
383@end deftypefn
384
385@c fopen_unlocked.c:39
386@deftypefn Extension {FILE *} fopen_unlocked (const char *@var{path}, const char * @var{mode})
387
388Opens and returns a @code{FILE} pointer via @code{fopen}.  If the
389operating system supports it, ensure that the stream is setup to avoid
390any multi-threaded locking.  Otherwise return the @code{FILE} pointer
391unchanged.
392
393@end deftypefn
394
395@c argv.c:97
396@deftypefn Extension void freeargv (char **@var{vector})
397
398Free an argument vector that was built using @code{buildargv}.  Simply
399scans through @var{vector}, freeing the memory for each argument until
400the terminating @code{NULL} is found, and then frees @var{vector}
401itself.
402
403@end deftypefn
404
405@c fopen_unlocked.c:57
406@deftypefn Extension {FILE *} freopen_unlocked (const char * @var{path}, const char * @var{mode}, FILE * @var{stream})
407
408Opens and returns a @code{FILE} pointer via @code{freopen}.  If the
409operating system supports it, ensure that the stream is setup to avoid
410any multi-threaded locking.  Otherwise return the @code{FILE} pointer
411unchanged.
412
413@end deftypefn
414
415@c getruntime.c:82
416@deftypefn Replacement long get_run_time (void)
417
418Returns the time used so far, in microseconds.  If possible, this is
419the time used by this process, else it is the elapsed time since the
420process started.
421
422@end deftypefn
423
424@c getcwd.c:6
425@deftypefn Supplemental char* getcwd (char *@var{pathname}, int @var{len})
426
427Copy the absolute pathname for the current working directory into
428@var{pathname}, which is assumed to point to a buffer of at least
429@var{len} bytes, and return a pointer to the buffer.  If the current
430directory's path doesn't fit in @var{len} characters, the result is
431@code{NULL} and @code{errno} is set.  If @var{pathname} is a null pointer,
432@code{getcwd} will obtain @var{len} bytes of space using
433@code{malloc}.
434
435@end deftypefn
436
437@c getpagesize.c:5
438@deftypefn Supplemental int getpagesize (void)
439
440Returns the number of bytes in a page of memory.  This is the
441granularity of many of the system memory management routines.  No
442guarantee is made as to whether or not it is the same as the basic
443memory management hardware page size.
444
445@end deftypefn
446
447@c getpwd.c:5
448@deftypefn Supplemental char* getpwd (void)
449
450Returns the current working directory.  This implementation caches the
451result on the assumption that the process will not call @code{chdir}
452between calls to @code{getpwd}.
453
454@end deftypefn
455
456@c gettimeofday.c:12
457@deftypefn Supplemental int gettimeofday (struct timeval *@var{tp}, void *@var{tz})
458
459Writes the current time to @var{tp}.  This implementation requires
460that @var{tz} be NULL.  Returns 0 on success, -1 on failure.
461
462@end deftypefn
463
464@c hex.c:33
465@deftypefn Extension void hex_init (void)
466
467Initializes the array mapping the current character set to
468corresponding hex values.  This function must be called before any
469call to @code{hex_p} or @code{hex_value}.  If you fail to call it, a
470default ASCII-based table will normally be used on ASCII systems.
471
472@end deftypefn
473
474@c hex.c:42
475@deftypefn Extension int hex_p (int @var{c})
476
477Evaluates to non-zero if the given character is a valid hex character,
478or zero if it is not.  Note that the value you pass will be cast to
479@code{unsigned char} within the macro.
480
481@end deftypefn
482
483@c hex.c:50
484@deftypefn Extension {unsigned int} hex_value (int @var{c})
485
486Returns the numeric equivalent of the given character when interpreted
487as a hexadecimal digit.  The result is undefined if you pass an
488invalid hex digit.  Note that the value you pass will be cast to
489@code{unsigned char} within the macro.
490
491The @code{hex_value} macro returns @code{unsigned int}, rather than
492signed @code{int}, to make it easier to use in parsing addresses from
493hex dump files: a signed @code{int} would be sign-extended when
494converted to a wider unsigned type --- like @code{bfd_vma}, on some
495systems.
496
497@end deftypefn
498
499@c hashtab.c:336
500@deftypefn Supplemental htab_t htab_create_typed_alloc (size_t @var{size},
501htab_hash @var{hash_f}, htab_eq @var{eq_f}, htab_del @var{del_f},
502htab_alloc @var{alloc_tab_f}, htab_alloc @var{alloc_f},
503htab_free @var{free_f})
504
505This function creates a hash table that uses two different allocators
506@var{alloc_tab_f} and @var{alloc_f} to use for allocating the table itself
507and its entries respectively.  This is useful when variables of different
508types need to be allocated with different allocators.
509
510The created hash table is slightly larger than @var{size} and it is
511initially empty (all the hash table entries are @code{HTAB_EMPTY_ENTRY}).
512The function returns the created hash table, or @code{NULL} if memory
513allocation fails.
514
515@end deftypefn
516
517@c index.c:5
518@deftypefn Supplemental char* index (char *@var{s}, int @var{c})
519
520Returns a pointer to the first occurrence of the character @var{c} in
521the string @var{s}, or @code{NULL} if not found.  The use of @code{index} is
522deprecated in new programs in favor of @code{strchr}.
523
524@end deftypefn
525
526@c insque.c:6
527@deftypefn Supplemental void insque (struct qelem *@var{elem}, struct qelem *@var{pred})
528@deftypefnx Supplemental void remque (struct qelem *@var{elem})
529
530Routines to manipulate queues built from doubly linked lists.  The
531@code{insque} routine inserts @var{elem} in the queue immediately
532after @var{pred}.  The @code{remque} routine removes @var{elem} from
533its containing queue.  These routines expect to be passed pointers to
534structures which have as their first members a forward pointer and a
535back pointer, like this prototype (although no prototype is provided):
536
537@example
538struct qelem @{
539  struct qelem *q_forw;
540  struct qelem *q_back;
541  char q_data[];
542@};
543@end example
544
545@end deftypefn
546
547@c safe-ctype.c:46
548@deffn  Extension ISALPHA  (@var{c})
549@deffnx Extension ISALNUM  (@var{c})
550@deffnx Extension ISBLANK  (@var{c})
551@deffnx Extension ISCNTRL  (@var{c})
552@deffnx Extension ISDIGIT  (@var{c})
553@deffnx Extension ISGRAPH  (@var{c})
554@deffnx Extension ISLOWER  (@var{c})
555@deffnx Extension ISPRINT  (@var{c})
556@deffnx Extension ISPUNCT  (@var{c})
557@deffnx Extension ISSPACE  (@var{c})
558@deffnx Extension ISUPPER  (@var{c})
559@deffnx Extension ISXDIGIT (@var{c})
560
561These twelve macros are defined by @file{safe-ctype.h}.  Each has the
562same meaning as the corresponding macro (with name in lowercase)
563defined by the standard header @file{ctype.h}.  For example,
564@code{ISALPHA} returns true for alphabetic characters and false for
565others.  However, there are two differences between these macros and
566those provided by @file{ctype.h}:
567
568@itemize @bullet
569@item These macros are guaranteed to have well-defined behavior for all
570values representable by @code{signed char} and @code{unsigned char}, and
571for @code{EOF}.
572
573@item These macros ignore the current locale; they are true for these
574fixed sets of characters:
575@multitable {@code{XDIGIT}} {yada yada yada yada yada yada yada yada}
576@item @code{ALPHA}  @tab @kbd{A-Za-z}
577@item @code{ALNUM}  @tab @kbd{A-Za-z0-9}
578@item @code{BLANK}  @tab @kbd{space tab}
579@item @code{CNTRL}  @tab @code{!PRINT}
580@item @code{DIGIT}  @tab @kbd{0-9}
581@item @code{GRAPH}  @tab @code{ALNUM || PUNCT}
582@item @code{LOWER}  @tab @kbd{a-z}
583@item @code{PRINT}  @tab @code{GRAPH ||} @kbd{space}
584@item @code{PUNCT}  @tab @kbd{`~!@@#$%^&*()_-=+[@{]@}\|;:'",<.>/?}
585@item @code{SPACE}  @tab @kbd{space tab \n \r \f \v}
586@item @code{UPPER}  @tab @kbd{A-Z}
587@item @code{XDIGIT} @tab @kbd{0-9A-Fa-f}
588@end multitable
589
590Note that, if the host character set is ASCII or a superset thereof,
591all these macros will return false for all values of @code{char} outside
592the range of 7-bit ASCII.  In particular, both ISPRINT and ISCNTRL return
593false for characters with numeric values from 128 to 255.
594@end itemize
595@end deffn
596
597@c safe-ctype.c:95
598@deffn  Extension ISIDNUM         (@var{c})
599@deffnx Extension ISIDST          (@var{c})
600@deffnx Extension IS_VSPACE       (@var{c})
601@deffnx Extension IS_NVSPACE      (@var{c})
602@deffnx Extension IS_SPACE_OR_NUL (@var{c})
603@deffnx Extension IS_ISOBASIC     (@var{c})
604These six macros are defined by @file{safe-ctype.h} and provide
605additional character classes which are useful when doing lexical
606analysis of C or similar languages.  They are true for the following
607sets of characters:
608
609@multitable {@code{SPACE_OR_NUL}} {yada yada yada yada yada yada yada yada}
610@item @code{IDNUM}        @tab @kbd{A-Za-z0-9_}
611@item @code{IDST}         @tab @kbd{A-Za-z_}
612@item @code{VSPACE}       @tab @kbd{\r \n}
613@item @code{NVSPACE}      @tab @kbd{space tab \f \v \0}
614@item @code{SPACE_OR_NUL} @tab @code{VSPACE || NVSPACE}
615@item @code{ISOBASIC}     @tab @code{VSPACE || NVSPACE || PRINT}
616@end multitable
617@end deffn
618
619@c lbasename.c:23
620@deftypefn Replacement {const char*} lbasename (const char *@var{name})
621
622Given a pointer to a string containing a typical pathname
623(@samp{/usr/src/cmd/ls/ls.c} for example), returns a pointer to the
624last component of the pathname (@samp{ls.c} in this case).  The
625returned pointer is guaranteed to lie within the original
626string.  This latter fact is not true of many vendor C
627libraries, which return special strings or modify the passed
628strings for particular input.
629
630In particular, the empty string returns the same empty string,
631and a path ending in @code{/} returns the empty string after it.
632
633@end deftypefn
634
635@c lrealpath.c:25
636@deftypefn Replacement {const char*} lrealpath (const char *@var{name})
637
638Given a pointer to a string containing a pathname, returns a canonical
639version of the filename.  Symlinks will be resolved, and ``.'' and ``..''
640components will be simplified.  The returned value will be allocated using
641@code{malloc}, or @code{NULL} will be returned on a memory allocation error.
642
643@end deftypefn
644
645@c make-relative-prefix.c:24
646@deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, const char *@var{bin_prefix}, const char *@var{prefix})
647
648Given three paths @var{progname}, @var{bin_prefix}, @var{prefix},
649return the path that is in the same position relative to
650@var{progname}'s directory as @var{prefix} is relative to
651@var{bin_prefix}.  That is, a string starting with the directory
652portion of @var{progname}, followed by a relative pathname of the
653difference between @var{bin_prefix} and @var{prefix}.
654
655If @var{progname} does not contain any directory separators,
656@code{make_relative_prefix} will search @env{PATH} to find a program
657named @var{progname}.  Also, if @var{progname} is a symbolic link,
658the symbolic link will be resolved.
659
660For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta},
661@var{prefix} is @code{/alpha/beta/gamma/omega/}, and @var{progname} is
662@code{/red/green/blue/gcc}, then this function will return
663@code{/red/green/blue/../../omega/}.
664
665The return value is normally allocated via @code{malloc}.  If no
666relative prefix can be found, return @code{NULL}.
667
668@end deftypefn
669
670@c make-temp-file.c:173
671@deftypefn Replacement char* make_temp_file (const char *@var{suffix})
672
673Return a temporary file name (as a string) or @code{NULL} if unable to
674create one.  @var{suffix} is a suffix to append to the file name.  The
675string is @code{malloc}ed, and the temporary file has been created.
676
677@end deftypefn
678
679@c memchr.c:3
680@deftypefn Supplemental void* memchr (const void *@var{s}, int @var{c}, size_t @var{n})
681
682This function searches memory starting at @code{*@var{s}} for the
683character @var{c}.  The search only ends with the first occurrence of
684@var{c}, or after @var{length} characters; in particular, a null
685character does not terminate the search.  If the character @var{c} is
686found within @var{length} characters of @code{*@var{s}}, a pointer
687to the character is returned.  If @var{c} is not found, then @code{NULL} is
688returned.
689
690@end deftypefn
691
692@c memcmp.c:6
693@deftypefn Supplemental int memcmp (const void *@var{x}, const void *@var{y}, size_t @var{count})
694
695Compares the first @var{count} bytes of two areas of memory.  Returns
696zero if they are the same, a value less than zero if @var{x} is
697lexically less than @var{y}, or a value greater than zero if @var{x}
698is lexically greater than @var{y}.  Note that lexical order is determined
699as if comparing unsigned char arrays.
700
701@end deftypefn
702
703@c memcpy.c:6
704@deftypefn Supplemental void* memcpy (void *@var{out}, const void *@var{in}, size_t @var{length})
705
706Copies @var{length} bytes from memory region @var{in} to region
707@var{out}.  Returns a pointer to @var{out}.
708
709@end deftypefn
710
711@c memmem.c:20
712@deftypefn Supplemental void* memmem (const void *@var{haystack}, size_t @var{haystack_len} const void *@var{needle}, size_t @var{needle_len})
713
714Returns a pointer to the first occurrence of @var{needle} (length
715@var{needle_len}) in @var{haystack} (length @var{haystack_len}).
716Returns @code{NULL} if not found.
717
718@end deftypefn
719
720@c memmove.c:6
721@deftypefn Supplemental void* memmove (void *@var{from}, const void *@var{to}, size_t @var{count})
722
723Copies @var{count} bytes from memory area @var{from} to memory area
724@var{to}, returning a pointer to @var{to}.
725
726@end deftypefn
727
728@c mempcpy.c:23
729@deftypefn Supplemental void* mempcpy (void *@var{out}, const void *@var{in}, size_t @var{length})
730
731Copies @var{length} bytes from memory region @var{in} to region
732@var{out}.  Returns a pointer to @var{out} + @var{length}.
733
734@end deftypefn
735
736@c memset.c:6
737@deftypefn Supplemental void* memset (void *@var{s}, int @var{c}, size_t @var{count})
738
739Sets the first @var{count} bytes of @var{s} to the constant byte
740@var{c}, returning a pointer to @var{s}.
741
742@end deftypefn
743
744@c mkstemps.c:58
745@deftypefn Replacement int mkstemps (char *@var{pattern}, int @var{suffix_len})
746
747Generate a unique temporary file name from @var{pattern}.
748@var{pattern} has the form:
749
750@example
751   @var{path}/ccXXXXXX@var{suffix}
752@end example
753
754@var{suffix_len} tells us how long @var{suffix} is (it can be zero
755length).  The last six characters of @var{pattern} before @var{suffix}
756must be @samp{XXXXXX}; they are replaced with a string that makes the
757filename unique.  Returns a file descriptor open on the file for
758reading and writing.
759
760@end deftypefn
761
762@c pexecute.txh:266
763@deftypefn Extension void pex_free (struct pex_obj @var{obj})
764
765Clean up and free all data associated with @var{obj}.  If you have not
766yet called @code{pex_get_times} or @code{pex_get_status}, this will
767try to kill the subprocesses.
768
769@end deftypefn
770
771@c pexecute.txh:241
772@deftypefn Extension int pex_get_status (struct pex_obj *@var{obj}, int @var{count}, int *@var{vector})
773
774Returns the exit status of all programs run using @var{obj}.
775@var{count} is the number of results expected.  The results will be
776placed into @var{vector}.  The results are in the order of the calls
777to @code{pex_run}.  Returns 0 on error, 1 on success.
778
779@end deftypefn
780
781@c pexecute.txh:250
782@deftypefn Extension int pex_get_times (struct pex_obj *@var{obj}, int @var{count}, struct pex_time *@var{vector})
783
784Returns the process execution times of all programs run using
785@var{obj}.  @var{count} is the number of results expected.  The
786results will be placed into @var{vector}.  The results are in the
787order of the calls to @code{pex_run}.  Returns 0 on error, 1 on
788success.
789
790@code{struct pex_time} has the following fields of the type
791@code{unsigned long}: @code{user_seconds},
792@code{user_microseconds}, @code{system_seconds},
793@code{system_microseconds}.  On systems which do not support reporting
794process times, all the fields will be set to @code{0}.
795
796@end deftypefn
797
798@c pexecute.txh:2
799@deftypefn Extension {struct pex_obj *} pex_init (int @var{flags}, const char *@var{pname}, const char *@var{tempbase})
800
801Prepare to execute one or more programs, with standard output of each
802program fed to standard input of the next.  This is a system
803independent interface to execute a pipeline.
804
805@var{flags} is a bitwise combination of the following:
806
807@table @code
808
809@vindex PEX_RECORD_TIMES
810@item PEX_RECORD_TIMES
811Record subprocess times if possible.
812
813@vindex PEX_USE_PIPES
814@item PEX_USE_PIPES
815Use pipes for communication between processes, if possible.
816
817@vindex PEX_SAVE_TEMPS
818@item PEX_SAVE_TEMPS
819Don't delete temporary files used for communication between
820processes.
821
822@end table
823
824@var{pname} is the name of program to be executed, used in error
825messages.  @var{tempbase} is a base name to use for any required
826temporary files; it may be @code{NULL} to use a randomly chosen name.
827
828@end deftypefn
829
830@c pexecute.txh:155
831@deftypefn Extension {FILE *} pex_input_file (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{in_name})
832
833Return a stream for a temporary file to pass to the first program in
834the pipeline as input.
835
836The name of the input file is chosen according to the same rules
837@code{pex_run} uses to choose output file names, based on
838@var{in_name}, @var{obj} and the @code{PEX_SUFFIX} bit in @var{flags}.
839
840Don't call @code{fclose} on the returned stream; the first call to
841@code{pex_run} closes it automatically.
842
843If @var{flags} includes @code{PEX_BINARY_OUTPUT}, open the stream in
844binary mode; otherwise, open it in the default mode.  Including
845@code{PEX_BINARY_OUTPUT} in @var{flags} has no effect on Unix.
846@end deftypefn
847
848@c pexecute.txh:172
849@deftypefn Extension {FILE *} pex_input_pipe (struct pex_obj *@var{obj}, int @var{binary})
850
851Return a stream @var{fp} for a pipe connected to the standard input of
852the first program in the pipeline; @var{fp} is opened for writing.
853You must have passed @code{PEX_USE_PIPES} to the @code{pex_init} call
854that returned @var{obj}.
855
856You must close @var{fp} using @code{fclose} yourself when you have
857finished writing data to the pipeline.
858
859The file descriptor underlying @var{fp} is marked not to be inherited
860by child processes.
861
862On systems that do not support pipes, this function returns
863@code{NULL}, and sets @code{errno} to @code{EINVAL}.  If you would
864like to write code that is portable to all systems the @code{pex}
865functions support, consider using @code{pex_input_file} instead.
866
867There are two opportunities for deadlock using
868@code{pex_input_pipe}:
869
870@itemize @bullet
871@item
872Most systems' pipes can buffer only a fixed amount of data; a process
873that writes to a full pipe blocks.  Thus, if you write to @file{fp}
874before starting the first process, you run the risk of blocking when
875there is no child process yet to read the data and allow you to
876continue.  @code{pex_input_pipe} makes no promises about the
877size of the pipe's buffer, so if you need to write any data at all
878before starting the first process in the pipeline, consider using
879@code{pex_input_file} instead.
880
881@item
882Using @code{pex_input_pipe} and @code{pex_read_output} together
883may also cause deadlock.  If the output pipe fills up, so that each
884program in the pipeline is waiting for the next to read more data, and
885you fill the input pipe by writing more data to @var{fp}, then there
886is no way to make progress: the only process that could read data from
887the output pipe is you, but you are blocked on the input pipe.
888
889@end itemize
890
891@end deftypefn
892
893@c pexecute.txh:274
894@deftypefn Extension {const char *} pex_one (int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{pname}, const char *@var{outname}, const char *@var{errname}, int *@var{status}, int *@var{err})
895
896An interface to permit the easy execution of a
897single program.  The return value and most of the parameters are as
898for a call to @code{pex_run}.  @var{flags} is restricted to a
899combination of @code{PEX_SEARCH}, @code{PEX_STDERR_TO_STDOUT}, and
900@code{PEX_BINARY_OUTPUT}.  @var{outname} is interpreted as if
901@code{PEX_LAST} were set.  On a successful return, @code{*@var{status}} will
902be set to the exit status of the program.
903
904@end deftypefn
905
906@c pexecute.txh:228
907@deftypefn Extension {FILE *} pex_read_err (struct pex_obj *@var{obj}, int @var{binary})
908
909Returns a @code{FILE} pointer which may be used to read the standard
910error of the last program in the pipeline.  When this is used,
911@code{PEX_LAST} should not be used in a call to @code{pex_run}.  After
912this is called, @code{pex_run} may no longer be called with the same
913@var{obj}.  @var{binary} should be non-zero if the file should be
914opened in binary mode.  Don't call @code{fclose} on the returned file;
915it will be closed by @code{pex_free}.
916
917@end deftypefn
918
919@c pexecute.txh:216
920@deftypefn Extension {FILE *} pex_read_output (struct pex_obj *@var{obj}, int @var{binary})
921
922Returns a @code{FILE} pointer which may be used to read the standard
923output of the last program in the pipeline.  When this is used,
924@code{PEX_LAST} should not be used in a call to @code{pex_run}.  After
925this is called, @code{pex_run} may no longer be called with the same
926@var{obj}.  @var{binary} should be non-zero if the file should be
927opened in binary mode.  Don't call @code{fclose} on the returned file;
928it will be closed by @code{pex_free}.
929
930@end deftypefn
931
932@c pexecute.txh:33
933@deftypefn Extension {const char *} pex_run (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{outname}, const char *@var{errname}, int *@var{err})
934
935Execute one program in a pipeline.  On success this returns
936@code{NULL}.  On failure it returns an error message, a statically
937allocated string.
938
939@var{obj} is returned by a previous call to @code{pex_init}.
940
941@var{flags} is a bitwise combination of the following:
942
943@table @code
944
945@vindex PEX_LAST
946@item PEX_LAST
947This must be set on the last program in the pipeline.  In particular,
948it should be set when executing a single program.  The standard output
949of the program will be sent to @var{outname}, or, if @var{outname} is
950@code{NULL}, to the standard output of the calling program.  Do @emph{not}
951set this bit if you want to call @code{pex_read_output}
952(described below).  After a call to @code{pex_run} with this bit set,
953@var{pex_run} may no longer be called with the same @var{obj}.
954
955@vindex PEX_SEARCH
956@item PEX_SEARCH
957Search for the program using the user's executable search path.
958
959@vindex PEX_SUFFIX
960@item PEX_SUFFIX
961@var{outname} is a suffix.  See the description of @var{outname},
962below.
963
964@vindex PEX_STDERR_TO_STDOUT
965@item PEX_STDERR_TO_STDOUT
966Send the program's standard error to standard output, if possible.
967
968@vindex PEX_BINARY_INPUT
969@vindex PEX_BINARY_OUTPUT
970@vindex PEX_BINARY_ERROR
971@item PEX_BINARY_INPUT
972@itemx PEX_BINARY_OUTPUT
973@itemx PEX_BINARY_ERROR
974The standard input (output or error) of the program should be read (written) in
975binary mode rather than text mode.  These flags are ignored on systems
976which do not distinguish binary mode and text mode, such as Unix.  For
977proper behavior these flags should match appropriately---a call to
978@code{pex_run} using @code{PEX_BINARY_OUTPUT} should be followed by a
979call using @code{PEX_BINARY_INPUT}.
980
981@vindex PEX_STDERR_TO_PIPE
982@item PEX_STDERR_TO_PIPE
983Send the program's standard error to a pipe, if possible.  This flag
984cannot be specified together with @code{PEX_STDERR_TO_STDOUT}.  This
985flag can be specified only on the last program in pipeline.
986
987@end table
988
989@var{executable} is the program to execute.  @var{argv} is the set of
990arguments to pass to the program; normally @code{@var{argv}[0]} will
991be a copy of @var{executable}.
992
993@var{outname} is used to set the name of the file to use for standard
994output.  There are two cases in which no output file will be used:
995
996@enumerate
997@item
998if @code{PEX_LAST} is not set in @var{flags}, and @code{PEX_USE_PIPES}
999was set in the call to @code{pex_init}, and the system supports pipes
1000
1001@item
1002if @code{PEX_LAST} is set in @var{flags}, and @var{outname} is
1003@code{NULL}
1004@end enumerate
1005
1006@noindent
1007Otherwise the code will use a file to hold standard
1008output.  If @code{PEX_LAST} is not set, this file is considered to be
1009a temporary file, and it will be removed when no longer needed, unless
1010@code{PEX_SAVE_TEMPS} was set in the call to @code{pex_init}.
1011
1012There are two cases to consider when setting the name of the file to
1013hold standard output.
1014
1015@enumerate
1016@item
1017@code{PEX_SUFFIX} is set in @var{flags}.  In this case
1018@var{outname} may not be @code{NULL}.  If the @var{tempbase} parameter
1019to @code{pex_init} was not @code{NULL}, then the output file name is
1020the concatenation of @var{tempbase} and @var{outname}.  If
1021@var{tempbase} was @code{NULL}, then the output file name is a random
1022file name ending in @var{outname}.
1023
1024@item
1025@code{PEX_SUFFIX} was not set in @var{flags}.  In this
1026case, if @var{outname} is not @code{NULL}, it is used as the output
1027file name.  If @var{outname} is @code{NULL}, and @var{tempbase} was
1028not NULL, the output file name is randomly chosen using
1029@var{tempbase}.  Otherwise the output file name is chosen completely
1030at random.
1031@end enumerate
1032
1033@var{errname} is the file name to use for standard error output.  If
1034it is @code{NULL}, standard error is the same as the caller's.
1035Otherwise, standard error is written to the named file.
1036
1037On an error return, the code sets @code{*@var{err}} to an @code{errno}
1038value, or to 0 if there is no relevant @code{errno}.
1039
1040@end deftypefn
1041
1042@c pexecute.txh:142
1043@deftypefn Extension {const char *} pex_run_in_environment (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{executable}, char * const *@var{argv}, char * const *@var{env}, int @var{env_size}, const char *@var{outname}, const char *@var{errname}, int *@var{err})
1044
1045Execute one program in a pipeline, permitting the environment for the
1046program to be specified.  Behaviour and parameters not listed below are
1047as for @code{pex_run}.
1048
1049@var{env} is the environment for the child process, specified as an array of
1050character pointers.  Each element of the array should point to a string of the
1051form @code{VAR=VALUE}, with the exception of the last element that must be
1052@code{NULL}.
1053
1054@end deftypefn
1055
1056@c pexecute.txh:286
1057@deftypefn Extension int pexecute (const char *@var{program}, char * const *@var{argv}, const char *@var{this_pname}, const char *@var{temp_base}, char **@var{errmsg_fmt}, char **@var{errmsg_arg}, int @var{flags})
1058
1059This is the old interface to execute one or more programs.  It is
1060still supported for compatibility purposes, but is no longer
1061documented.
1062
1063@end deftypefn
1064
1065@c strsignal.c:541
1066@deftypefn Supplemental void psignal (int @var{signo}, char *@var{message})
1067
1068Print @var{message} to the standard error, followed by a colon,
1069followed by the description of the signal specified by @var{signo},
1070followed by a newline.
1071
1072@end deftypefn
1073
1074@c putenv.c:21
1075@deftypefn Supplemental int putenv (const char *@var{string})
1076
1077Uses @code{setenv} or @code{unsetenv} to put @var{string} into
1078the environment or remove it.  If @var{string} is of the form
1079@samp{name=value} the string is added; if no @samp{=} is present the
1080name is unset/removed.
1081
1082@end deftypefn
1083
1084@c pexecute.txh:294
1085@deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags})
1086
1087Another part of the old execution interface.
1088
1089@end deftypefn
1090
1091@c random.c:39
1092@deftypefn Supplement {long int} random (void)
1093@deftypefnx Supplement void srandom (unsigned int @var{seed})
1094@deftypefnx Supplement void* initstate (unsigned int @var{seed}, void *@var{arg_state}, unsigned long @var{n})
1095@deftypefnx Supplement void* setstate (void *@var{arg_state})
1096
1097Random number functions.  @code{random} returns a random number in the
1098range 0 to @code{LONG_MAX}.  @code{srandom} initializes the random
1099number generator to some starting point determined by @var{seed}
1100(else, the values returned by @code{random} are always the same for each
1101run of the program).  @code{initstate} and @code{setstate} allow fine-grained
1102control over the state of the random number generator.
1103
1104@end deftypefn
1105
1106@c concat.c:173
1107@deftypefn Extension char* reconcat (char *@var{optr}, const char *@var{s1}, @dots{}, @code{NULL})
1108
1109Same as @code{concat}, except that if @var{optr} is not @code{NULL} it
1110is freed after the string is created.  This is intended to be useful
1111when you're extending an existing string or building up a string in a
1112loop:
1113
1114@example
1115  str = reconcat (str, "pre-", str, NULL);
1116@end example
1117
1118@end deftypefn
1119
1120@c rename.c:6
1121@deftypefn Supplemental int rename (const char *@var{old}, const char *@var{new})
1122
1123Renames a file from @var{old} to @var{new}.  If @var{new} already
1124exists, it is removed.
1125
1126@end deftypefn
1127
1128@c rindex.c:5
1129@deftypefn Supplemental char* rindex (const char *@var{s}, int @var{c})
1130
1131Returns a pointer to the last occurrence of the character @var{c} in
1132the string @var{s}, or @code{NULL} if not found.  The use of @code{rindex} is
1133deprecated in new programs in favor of @code{strrchr}.
1134
1135@end deftypefn
1136
1137@c setenv.c:22
1138@deftypefn Supplemental int setenv (const char *@var{name}, const char *@var{value}, int @var{overwrite})
1139@deftypefnx Supplemental void unsetenv (const char *@var{name})
1140
1141@code{setenv} adds @var{name} to the environment with value
1142@var{value}.  If the name was already present in the environment,
1143the new value will be stored only if @var{overwrite} is nonzero.
1144The companion @code{unsetenv} function removes @var{name} from the
1145environment.  This implementation is not safe for multithreaded code.
1146
1147@end deftypefn
1148
1149@c setproctitle.c:30
1150@deftypefn Supplemental void setproctitle (const char *@var{fmt} ...)
1151
1152Set the title of a process to @var{fmt}. va args not supported for now,
1153but defined for compatibility with BSD.
1154
1155@end deftypefn
1156
1157@c strsignal.c:348
1158@deftypefn Extension int signo_max (void)
1159
1160Returns the maximum signal value for which a corresponding symbolic
1161name or message is available.  Note that in the case where we use the
1162@code{sys_siglist} supplied by the system, it is possible for there to
1163be more symbolic names than messages, or vice versa.  In fact, the
1164manual page for @code{psignal(3b)} explicitly warns that one should
1165check the size of the table (@code{NSIG}) before indexing it, since
1166new signal codes may be added to the system before they are added to
1167the table.  Thus @code{NSIG} might be smaller than value implied by
1168the largest signo value defined in @code{<signal.h>}.
1169
1170We return the maximum value that can be used to obtain a meaningful
1171symbolic name or message.
1172
1173@end deftypefn
1174
1175@c sigsetmask.c:8
1176@deftypefn Supplemental int sigsetmask (int @var{set})
1177
1178Sets the signal mask to the one provided in @var{set} and returns
1179the old mask (which, for libiberty's implementation, will always
1180be the value @code{1}).
1181
1182@end deftypefn
1183
1184@c simple-object.txh:87
1185@deftypefn Extension {const char *} simple_object_attributes_compare (simple_object_attributes *@var{attrs1}, simple_object_attributes *@var{attrs2}, int *@var{err})
1186
1187Compare @var{attrs1} and @var{attrs2}.  If they could be linked
1188together without error, return @code{NULL}.  Otherwise, return an
1189error message and set @code{*@var{err}} to an errno value or @code{0}
1190if there is no relevant errno.
1191
1192@end deftypefn
1193
1194@c simple-object.txh:73
1195@deftypefn Extension {simple_object_attributes *} simple_object_fetch_attributes (simple_object_read *@var{simple_object}, const char **@var{errmsg}, int *@var{err})
1196
1197Fetch the attributes of @var{simple_object}.  The attributes are
1198internal information such as the format of the object file, or the
1199architecture it was compiled for.  This information will persist until
1200@code{simple_object_attributes_release} is called, even if
1201@var{simple_object} itself is released.
1202
1203On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an
1204error message, and sets @code{*@var{err}} to an errno value or
1205@code{0} if there is no relevant errno.
1206
1207@end deftypefn
1208
1209@c simple-object.txh:44
1210@deftypefn Extension {int} simple_object_find_section (simple_object_read *@var{simple_object} off_t *@var{offset}, off_t *@var{length}, const char **@var{errmsg}, int *@var{err})
1211
1212Look for the section @var{name} in @var{simple_object}.  This returns
1213information for the first section with that name.
1214
1215If found, return 1 and set @code{*@var{offset}} to the offset in the
1216file of the section contents and set @code{*@var{length}} to the
1217length of the section contents.  The value in @code{*@var{offset}}
1218will be relative to the offset passed to
1219@code{simple_object_open_read}.
1220
1221If the section is not found, and no error occurs,
1222@code{simple_object_find_section} returns @code{0} and set
1223@code{*@var{errmsg}} to @code{NULL}.
1224
1225If an error occurs, @code{simple_object_find_section} returns
1226@code{0}, sets @code{*@var{errmsg}} to an error message, and sets
1227@code{*@var{err}} to an errno value or @code{0} if there is no
1228relevant errno.
1229
1230@end deftypefn
1231
1232@c simple-object.txh:25
1233@deftypefn Extension {const char *} simple_object_find_sections (simple_object_read *@var{simple_object}, int (*@var{pfn}) (void *@var{data}, const char *@var{name}, off_t @var{offset}, off_t @var{length}), void *@var{data}, int *@var{err})
1234
1235This function calls @var{pfn} for each section in @var{simple_object}.
1236It calls @var{pfn} with the section name, the offset within the file
1237of the section contents, and the length of the section contents.  The
1238offset within the file is relative to the offset passed to
1239@code{simple_object_open_read}.  The @var{data} argument to this
1240function is passed along to @var{pfn}.
1241
1242If @var{pfn} returns @code{0}, the loop over the sections stops and
1243@code{simple_object_find_sections} returns.  If @var{pfn} returns some
1244other value, the loop continues.
1245
1246On success @code{simple_object_find_sections} returns.  On error it
1247returns an error string, and sets @code{*@var{err}} to an errno value
1248or @code{0} if there is no relevant errno.
1249
1250@end deftypefn
1251
1252@c simple-object.txh:2
1253@deftypefn Extension {simple_object_read *} simple_object_open_read (int @var{descriptor}, off_t @var{offset}, const char *{segment_name}, const char **@var{errmsg}, int *@var{err})
1254
1255Opens an object file for reading.  Creates and returns an
1256@code{simple_object_read} pointer which may be passed to other
1257functions to extract data from the object file.
1258
1259@var{descriptor} holds a file descriptor which permits reading.
1260
1261@var{offset} is the offset into the file; this will be @code{0} in the
1262normal case, but may be a different value when reading an object file
1263in an archive file.
1264
1265@var{segment_name} is only used with the Mach-O file format used on
1266Darwin aka Mac OS X.  It is required on that platform, and means to
1267only look at sections within the segment with that name.  The
1268parameter is ignored on other systems.
1269
1270If an error occurs, this functions returns @code{NULL} and sets
1271@code{*@var{errmsg}} to an error string and sets @code{*@var{err}} to
1272an errno value or @code{0} if there is no relevant errno.
1273
1274@end deftypefn
1275
1276@c simple-object.txh:96
1277@deftypefn Extension {void} simple_object_release_attributes (simple_object_attributes *@var{attrs})
1278
1279Release all resources associated with @var{attrs}.
1280
1281@end deftypefn
1282
1283@c simple-object.txh:66
1284@deftypefn Extension {void} simple_object_release_read (simple_object_read *@var{simple_object})
1285
1286Release all resources associated with @var{simple_object}.  This does
1287not close the file descriptor.
1288
1289@end deftypefn
1290
1291@c simple-object.txh:164
1292@deftypefn Extension {void} simple_object_release_write (simple_object_write *@var{simple_object})
1293
1294Release all resources associated with @var{simple_object}.
1295
1296@end deftypefn
1297
1298@c simple-object.txh:102
1299@deftypefn Extension {simple_object_write *} simple_object_start_write (simple_object_attributes @var{attrs}, const char *@var{segment_name}, const char **@var{errmsg}, int *@var{err})
1300
1301Start creating a new object file using the object file format
1302described in @var{attrs}.  You must fetch attribute information from
1303an existing object file before you can create a new one.  There is
1304currently no support for creating an object file de novo.
1305
1306@var{segment_name} is only used with Mach-O as found on Darwin aka Mac
1307OS X.  The parameter is required on that target.  It means that all
1308sections are created within the named segment.  It is ignored for
1309other object file formats.
1310
1311On error @code{simple_object_start_write} returns @code{NULL}, sets
1312@code{*@var{ERRMSG}} to an error message, and sets @code{*@var{err}}
1313to an errno value or @code{0} if there is no relevant errno.
1314
1315@end deftypefn
1316
1317@c simple-object.txh:137
1318@deftypefn Extension {const char *} simple_object_write_add_data (simple_object_write *@var{simple_object}, simple_object_write_section *@var{section}, const void *@var{buffer}, size_t @var{size}, int @var{copy}, int *@var{err})
1319
1320Add data @var{buffer}/@var{size} to @var{section} in
1321@var{simple_object}.  If @var{copy} is non-zero, the data will be
1322copied into memory if necessary.  If @var{copy} is zero, @var{buffer}
1323must persist until @code{simple_object_write_to_file} is called.  is
1324released.
1325
1326On success this returns @code{NULL}.  On error this returns an error
1327message, and sets @code{*@var{err}} to an errno value or 0 if there is
1328no relevant erro.
1329
1330@end deftypefn
1331
1332@c simple-object.txh:120
1333@deftypefn Extension {simple_object_write_section *} simple_object_write_create_section (simple_object_write *@var{simple_object}, const char *@var{name}, unsigned int @var{align}, const char **@var{errmsg}, int *@var{err})
1334
1335Add a section to @var{simple_object}.  @var{name} is the name of the
1336new section.  @var{align} is the required alignment expressed as the
1337number of required low-order 0 bits (e.g., 2 for alignment to a 32-bit
1338boundary).
1339
1340The section is created as containing data, readable, not writable, not
1341executable, not loaded at runtime.  The section is not written to the
1342file until @code{simple_object_write_to_file} is called.
1343
1344On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an
1345error message, and sets @code{*@var{err}} to an errno value or
1346@code{0} if there is no relevant errno.
1347
1348@end deftypefn
1349
1350@c simple-object.txh:151
1351@deftypefn Extension {const char *} simple_object_write_to_file (simple_object_write *@var{simple_object}, int @var{descriptor}, int *@var{err})
1352
1353Write the complete object file to @var{descriptor}, an open file
1354descriptor.  This writes out all the data accumulated by calls to
1355@code{simple_object_write_create_section} and
1356@var{simple_object_write_add_data}.
1357
1358This returns @code{NULL} on success.  On error this returns an error
1359message and sets @code{*@var{err}} to an errno value or @code{0} if
1360there is no relevant errno.
1361
1362@end deftypefn
1363
1364@c snprintf.c:28
1365@deftypefn Supplemental int snprintf (char *@var{buf}, size_t @var{n}, const char *@var{format}, ...)
1366
1367This function is similar to @code{sprintf}, but it will write to
1368@var{buf} at most @code{@var{n}-1} bytes of text, followed by a
1369terminating null byte, for a total of @var{n} bytes.
1370On error the return value is -1, otherwise it returns the number of
1371bytes, not including the terminating null byte, that would have been
1372written had @var{n} been sufficiently large, regardless of the actual
1373value of @var{n}.  Note some pre-C99 system libraries do not implement
1374this correctly so users cannot generally rely on the return value if
1375the system version of this function is used.
1376
1377@end deftypefn
1378
1379@c spaces.c:22
1380@deftypefn Extension char* spaces (int @var{count})
1381
1382Returns a pointer to a memory region filled with the specified
1383number of spaces and null terminated.  The returned pointer is
1384valid until at least the next call.
1385
1386@end deftypefn
1387
1388@c stpcpy.c:23
1389@deftypefn Supplemental char* stpcpy (char *@var{dst}, const char *@var{src})
1390
1391Copies the string @var{src} into @var{dst}.  Returns a pointer to
1392@var{dst} + strlen(@var{src}).
1393
1394@end deftypefn
1395
1396@c stpncpy.c:23
1397@deftypefn Supplemental char* stpncpy (char *@var{dst}, const char *@var{src}, size_t @var{len})
1398
1399Copies the string @var{src} into @var{dst}, copying exactly @var{len}
1400and padding with zeros if necessary.  If @var{len} < strlen(@var{src})
1401then return @var{dst} + @var{len}, otherwise returns @var{dst} +
1402strlen(@var{src}).
1403
1404@end deftypefn
1405
1406@c strcasecmp.c:15
1407@deftypefn Supplemental int strcasecmp (const char *@var{s1}, const char *@var{s2})
1408
1409A case-insensitive @code{strcmp}.
1410
1411@end deftypefn
1412
1413@c strchr.c:6
1414@deftypefn Supplemental char* strchr (const char *@var{s}, int @var{c})
1415
1416Returns a pointer to the first occurrence of the character @var{c} in
1417the string @var{s}, or @code{NULL} if not found.  If @var{c} is itself the
1418null character, the results are undefined.
1419
1420@end deftypefn
1421
1422@c strdup.c:3
1423@deftypefn Supplemental char* strdup (const char *@var{s})
1424
1425Returns a pointer to a copy of @var{s} in memory obtained from
1426@code{malloc}, or @code{NULL} if insufficient memory was available.
1427
1428@end deftypefn
1429
1430@c strerror.c:670
1431@deftypefn Replacement {const char*} strerrno (int @var{errnum})
1432
1433Given an error number returned from a system call (typically returned
1434in @code{errno}), returns a pointer to a string containing the
1435symbolic name of that error number, as found in @code{<errno.h>}.
1436
1437If the supplied error number is within the valid range of indices for
1438symbolic names, but no name is available for the particular error
1439number, then returns the string @samp{Error @var{num}}, where @var{num}
1440is the error number.
1441
1442If the supplied error number is not within the range of valid
1443indices, then returns @code{NULL}.
1444
1445The contents of the location pointed to are only guaranteed to be
1446valid until the next call to @code{strerrno}.
1447
1448@end deftypefn
1449
1450@c strerror.c:603
1451@deftypefn Supplemental char* strerror (int @var{errnoval})
1452
1453Maps an @code{errno} number to an error message string, the contents
1454of which are implementation defined.  On systems which have the
1455external variables @code{sys_nerr} and @code{sys_errlist}, these
1456strings will be the same as the ones used by @code{perror}.
1457
1458If the supplied error number is within the valid range of indices for
1459the @code{sys_errlist}, but no message is available for the particular
1460error number, then returns the string @samp{Error @var{num}}, where
1461@var{num} is the error number.
1462
1463If the supplied error number is not a valid index into
1464@code{sys_errlist}, returns @code{NULL}.
1465
1466The returned string is only guaranteed to be valid only until the
1467next call to @code{strerror}.
1468
1469@end deftypefn
1470
1471@c strncasecmp.c:15
1472@deftypefn Supplemental int strncasecmp (const char *@var{s1}, const char *@var{s2})
1473
1474A case-insensitive @code{strncmp}.
1475
1476@end deftypefn
1477
1478@c strncmp.c:6
1479@deftypefn Supplemental int strncmp (const char *@var{s1}, const char *@var{s2}, size_t @var{n})
1480
1481Compares the first @var{n} bytes of two strings, returning a value as
1482@code{strcmp}.
1483
1484@end deftypefn
1485
1486@c strndup.c:23
1487@deftypefn Extension char* strndup (const char *@var{s}, size_t @var{n})
1488
1489Returns a pointer to a copy of @var{s} with at most @var{n} characters
1490in memory obtained from @code{malloc}, or @code{NULL} if insufficient
1491memory was available.  The result is always NUL terminated.
1492
1493@end deftypefn
1494
1495@c strrchr.c:6
1496@deftypefn Supplemental char* strrchr (const char *@var{s}, int @var{c})
1497
1498Returns a pointer to the last occurrence of the character @var{c} in
1499the string @var{s}, or @code{NULL} if not found.  If @var{c} is itself the
1500null character, the results are undefined.
1501
1502@end deftypefn
1503
1504@c strsignal.c:383
1505@deftypefn Supplemental {const char *} strsignal (int @var{signo})
1506
1507Maps an signal number to an signal message string, the contents of
1508which are implementation defined.  On systems which have the external
1509variable @code{sys_siglist}, these strings will be the same as the
1510ones used by @code{psignal()}.
1511
1512If the supplied signal number is within the valid range of indices for
1513the @code{sys_siglist}, but no message is available for the particular
1514signal number, then returns the string @samp{Signal @var{num}}, where
1515@var{num} is the signal number.
1516
1517If the supplied signal number is not a valid index into
1518@code{sys_siglist}, returns @code{NULL}.
1519
1520The returned string is only guaranteed to be valid only until the next
1521call to @code{strsignal}.
1522
1523@end deftypefn
1524
1525@c strsignal.c:448
1526@deftypefn Extension {const char*} strsigno (int @var{signo})
1527
1528Given an signal number, returns a pointer to a string containing the
1529symbolic name of that signal number, as found in @code{<signal.h>}.
1530
1531If the supplied signal number is within the valid range of indices for
1532symbolic names, but no name is available for the particular signal
1533number, then returns the string @samp{Signal @var{num}}, where
1534@var{num} is the signal number.
1535
1536If the supplied signal number is not within the range of valid
1537indices, then returns @code{NULL}.
1538
1539The contents of the location pointed to are only guaranteed to be
1540valid until the next call to @code{strsigno}.
1541
1542@end deftypefn
1543
1544@c strstr.c:6
1545@deftypefn Supplemental char* strstr (const char *@var{string}, const char *@var{sub})
1546
1547This function searches for the substring @var{sub} in the string
1548@var{string}, not including the terminating null characters.  A pointer
1549to the first occurrence of @var{sub} is returned, or @code{NULL} if the
1550substring is absent.  If @var{sub} points to a string with zero
1551length, the function returns @var{string}.
1552
1553@end deftypefn
1554
1555@c strtod.c:27
1556@deftypefn Supplemental double strtod (const char *@var{string}, char **@var{endptr})
1557
1558This ISO C function converts the initial portion of @var{string} to a
1559@code{double}.  If @var{endptr} is not @code{NULL}, a pointer to the
1560character after the last character used in the conversion is stored in
1561the location referenced by @var{endptr}.  If no conversion is
1562performed, zero is returned and the value of @var{string} is stored in
1563the location referenced by @var{endptr}.
1564
1565@end deftypefn
1566
1567@c strerror.c:729
1568@deftypefn Extension int strtoerrno (const char *@var{name})
1569
1570Given the symbolic name of a error number (e.g., @code{EACCES}), map it
1571to an errno value.  If no translation is found, returns 0.
1572
1573@end deftypefn
1574
1575@c strtol.c:33
1576@deftypefn Supplemental {long int} strtol (const char *@var{string}, char **@var{endptr}, int @var{base})
1577@deftypefnx Supplemental {unsigned long int} strtoul (const char *@var{string}, char **@var{endptr}, int @var{base})
1578
1579The @code{strtol} function converts the string in @var{string} to a
1580long integer value according to the given @var{base}, which must be
1581between 2 and 36 inclusive, or be the special value 0.  If @var{base}
1582is 0, @code{strtol} will look for the prefixes @code{0} and @code{0x}
1583to indicate bases 8 and 16, respectively, else default to base 10.
1584When the base is 16 (either explicitly or implicitly), a prefix of
1585@code{0x} is allowed.  The handling of @var{endptr} is as that of
1586@code{strtod} above.  The @code{strtoul} function is the same, except
1587that the converted value is unsigned.
1588
1589@end deftypefn
1590
1591@c strsignal.c:502
1592@deftypefn Extension int strtosigno (const char *@var{name})
1593
1594Given the symbolic name of a signal, map it to a signal number.  If no
1595translation is found, returns 0.
1596
1597@end deftypefn
1598
1599@c strverscmp.c:25
1600@deftypefun int strverscmp (const char *@var{s1}, const char *@var{s2})
1601The @code{strverscmp} function compares the string @var{s1} against
1602@var{s2}, considering them as holding indices/version numbers.  Return
1603value follows the same conventions as found in the @code{strverscmp}
1604function.  In fact, if @var{s1} and @var{s2} contain no digits,
1605@code{strverscmp} behaves like @code{strcmp}.
1606
1607Basically, we compare strings normally (character by character), until
1608we find a digit in each string - then we enter a special comparison
1609mode, where each sequence of digits is taken as a whole.  If we reach the
1610end of these two parts without noticing a difference, we return to the
1611standard comparison mode.  There are two types of numeric parts:
1612"integral" and "fractional" (those  begin with a '0'). The types
1613of the numeric parts affect the way we sort them:
1614
1615@itemize @bullet
1616@item
1617integral/integral: we compare values as you would expect.
1618
1619@item
1620fractional/integral: the fractional part is less than the integral one.
1621Again, no surprise.
1622
1623@item
1624fractional/fractional: the things become a bit more complex.
1625If the common prefix contains only leading zeroes, the longest part is less
1626than the other one; else the comparison behaves normally.
1627@end itemize
1628
1629@smallexample
1630strverscmp ("no digit", "no digit")
1631    @result{} 0    // @r{same behavior as strcmp.}
1632strverscmp ("item#99", "item#100")
1633    @result{} <0   // @r{same prefix, but 99 < 100.}
1634strverscmp ("alpha1", "alpha001")
1635    @result{} >0   // @r{fractional part inferior to integral one.}
1636strverscmp ("part1_f012", "part1_f01")
1637    @result{} >0   // @r{two fractional parts.}
1638strverscmp ("foo.009", "foo.0")
1639    @result{} <0   // @r{idem, but with leading zeroes only.}
1640@end smallexample
1641
1642This function is especially useful when dealing with filename sorting,
1643because filenames frequently hold indices/version numbers.
1644@end deftypefun
1645
1646@c tmpnam.c:3
1647@deftypefn Supplemental char* tmpnam (char *@var{s})
1648
1649This function attempts to create a name for a temporary file, which
1650will be a valid file name yet not exist when @code{tmpnam} checks for
1651it.  @var{s} must point to a buffer of at least @code{L_tmpnam} bytes,
1652or be @code{NULL}.  Use of this function creates a security risk, and it must
1653not be used in new projects.  Use @code{mkstemp} instead.
1654
1655@end deftypefn
1656
1657@c unlink-if-ordinary.c:27
1658@deftypefn Supplemental int unlink_if_ordinary (const char*)
1659
1660Unlinks the named file, unless it is special (e.g. a device file).
1661Returns 0 when the file was unlinked, a negative value (and errno set) when
1662there was an error deleting the file, and a positive value if no attempt
1663was made to unlink the file because it is special.
1664
1665@end deftypefn
1666
1667@c fopen_unlocked.c:31
1668@deftypefn Extension void unlock_std_streams (void)
1669
1670If the OS supports it, ensure that the standard I/O streams,
1671@code{stdin}, @code{stdout} and @code{stderr} are setup to avoid any
1672multi-threaded locking.  Otherwise do nothing.
1673
1674@end deftypefn
1675
1676@c fopen_unlocked.c:23
1677@deftypefn Extension void unlock_stream (FILE * @var{stream})
1678
1679If the OS supports it, ensure that the supplied stream is setup to
1680avoid any multi-threaded locking.  Otherwise leave the @code{FILE}
1681pointer unchanged.  If the @var{stream} is @code{NULL} do nothing.
1682
1683@end deftypefn
1684
1685@c vasprintf.c:47
1686@deftypefn Extension int vasprintf (char **@var{resptr}, const char *@var{format}, va_list @var{args})
1687
1688Like @code{vsprintf}, but instead of passing a pointer to a buffer,
1689you pass a pointer to a pointer.  This function will compute the size
1690of the buffer needed, allocate memory with @code{malloc}, and store a
1691pointer to the allocated memory in @code{*@var{resptr}}.  The value
1692returned is the same as @code{vsprintf} would return.  If memory could
1693not be allocated, minus one is returned and @code{NULL} is stored in
1694@code{*@var{resptr}}.
1695
1696@end deftypefn
1697
1698@c vfork.c:6
1699@deftypefn Supplemental int vfork (void)
1700
1701Emulates @code{vfork} by calling @code{fork} and returning its value.
1702
1703@end deftypefn
1704
1705@c vprintf.c:3
1706@deftypefn Supplemental int vprintf (const char *@var{format}, va_list @var{ap})
1707@deftypefnx Supplemental int vfprintf (FILE *@var{stream}, const char *@var{format}, va_list @var{ap})
1708@deftypefnx Supplemental int vsprintf (char *@var{str}, const char *@var{format}, va_list @var{ap})
1709
1710These functions are the same as @code{printf}, @code{fprintf}, and
1711@code{sprintf}, respectively, except that they are called with a
1712@code{va_list} instead of a variable number of arguments.  Note that
1713they do not call @code{va_end}; this is the application's
1714responsibility.  In @libib{} they are implemented in terms of the
1715nonstandard but common function @code{_doprnt}.
1716
1717@end deftypefn
1718
1719@c vsnprintf.c:28
1720@deftypefn Supplemental int vsnprintf (char *@var{buf}, size_t @var{n}, const char *@var{format}, va_list @var{ap})
1721
1722This function is similar to @code{vsprintf}, but it will write to
1723@var{buf} at most @code{@var{n}-1} bytes of text, followed by a
1724terminating null byte, for a total of @var{n} bytes.  On error the
1725return value is -1, otherwise it returns the number of characters that
1726would have been printed had @var{n} been sufficiently large,
1727regardless of the actual value of @var{n}.  Note some pre-C99 system
1728libraries do not implement this correctly so users cannot generally
1729rely on the return value if the system version of this function is
1730used.
1731
1732@end deftypefn
1733
1734@c waitpid.c:3
1735@deftypefn Supplemental int waitpid (int @var{pid}, int *@var{status}, int)
1736
1737This is a wrapper around the @code{wait} function.  Any ``special''
1738values of @var{pid} depend on your implementation of @code{wait}, as
1739does the return value.  The third argument is unused in @libib{}.
1740
1741@end deftypefn
1742
1743@c argv.c:306
1744@deftypefn Extension int writeargv (const char **@var{argv}, FILE *@var{file})
1745
1746Write each member of ARGV, handling all necessary quoting, to the file
1747named by FILE, separated by whitespace.  Return 0 on success, non-zero
1748if an error occurred while writing to FILE.
1749
1750@end deftypefn
1751
1752@c xatexit.c:11
1753@deftypefun int xatexit (void (*@var{fn}) (void))
1754
1755Behaves as the standard @code{atexit} function, but with no limit on
1756the number of registered functions.  Returns 0 on success, or @minus{}1 on
1757failure.  If you use @code{xatexit} to register functions, you must use
1758@code{xexit} to terminate your program.
1759
1760@end deftypefun
1761
1762@c xmalloc.c:38
1763@deftypefn Replacement void* xcalloc (size_t @var{nelem}, size_t @var{elsize})
1764
1765Allocate memory without fail, and set it to zero.  This routine functions
1766like @code{calloc}, but will behave the same as @code{xmalloc} if memory
1767cannot be found.
1768
1769@end deftypefn
1770
1771@c xexit.c:22
1772@deftypefn Replacement void xexit (int @var{code})
1773
1774Terminates the program.  If any functions have been registered with
1775the @code{xatexit} replacement function, they will be called first.
1776Termination is handled via the system's normal @code{exit} call.
1777
1778@end deftypefn
1779
1780@c xmalloc.c:22
1781@deftypefn Replacement void* xmalloc (size_t)
1782
1783Allocate memory without fail.  If @code{malloc} fails, this will print
1784a message to @code{stderr} (using the name set by
1785@code{xmalloc_set_program_name},
1786if any) and then call @code{xexit}.  Note that it is therefore safe for
1787a program to contain @code{#define malloc xmalloc} in its source.
1788
1789@end deftypefn
1790
1791@c xmalloc.c:53
1792@deftypefn Replacement void xmalloc_failed (size_t)
1793
1794This function is not meant to be called by client code, and is listed
1795here for completeness only.  If any of the allocation routines fail, this
1796function will be called to print an error message and terminate execution.
1797
1798@end deftypefn
1799
1800@c xmalloc.c:46
1801@deftypefn Replacement void xmalloc_set_program_name (const char *@var{name})
1802
1803You can use this to set the name of the program used by
1804@code{xmalloc_failed} when printing a failure message.
1805
1806@end deftypefn
1807
1808@c xmemdup.c:7
1809@deftypefn Replacement void* xmemdup (void *@var{input}, size_t @var{copy_size}, size_t @var{alloc_size})
1810
1811Duplicates a region of memory without fail.  First, @var{alloc_size} bytes
1812are allocated, then @var{copy_size} bytes from @var{input} are copied into
1813it, and the new memory is returned.  If fewer bytes are copied than were
1814allocated, the remaining memory is zeroed.
1815
1816@end deftypefn
1817
1818@c xmalloc.c:32
1819@deftypefn Replacement void* xrealloc (void *@var{ptr}, size_t @var{size})
1820Reallocate memory without fail.  This routine functions like @code{realloc},
1821but will behave the same as @code{xmalloc} if memory cannot be found.
1822
1823@end deftypefn
1824
1825@c xstrdup.c:7
1826@deftypefn Replacement char* xstrdup (const char *@var{s})
1827
1828Duplicates a character string without fail, using @code{xmalloc} to
1829obtain memory.
1830
1831@end deftypefn
1832
1833@c xstrerror.c:7
1834@deftypefn Replacement char* xstrerror (int @var{errnum})
1835
1836Behaves exactly like the standard @code{strerror} function, but
1837will never return a @code{NULL} pointer.
1838
1839@end deftypefn
1840
1841@c xstrndup.c:23
1842@deftypefn Replacement char* xstrndup (const char *@var{s}, size_t @var{n})
1843
1844Returns a pointer to a copy of @var{s} with at most @var{n} characters
1845without fail, using @code{xmalloc} to obtain memory.  The result is
1846always NUL terminated.
1847
1848@end deftypefn
1849
1850
1851