xref: /netbsd-src/usr.bin/man/man.c (revision 313c6c94c424eed90c7b7e494aa83308a0a5d0ce)
1 /*	$NetBSD: man.c,v 1.37 2008/07/21 14:19:24 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1987, 1993, 1994, 1995
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 
34 #ifndef lint
35 __COPYRIGHT("@(#) Copyright (c) 1987, 1993, 1994, 1995\
36  The Regents of the University of California.  All rights reserved.");
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)man.c	8.17 (Berkeley) 1/31/95";
42 #else
43 __RCSID("$NetBSD: man.c,v 1.37 2008/07/21 14:19:24 lukem Exp $");
44 #endif
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 #include <sys/queue.h>
49 #include <sys/utsname.h>
50 
51 #include <ctype.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <fnmatch.h>
56 #include <glob.h>
57 #include <signal.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <unistd.h>
62 #include <util.h>
63 
64 #include "manconf.h"
65 #include "pathnames.h"
66 
67 #ifndef MAN_DEBUG
68 #define MAN_DEBUG 0		/* debug path output */
69 #endif
70 
71 /*
72  * manstate: structure collecting the current global state so we can
73  * easily identify it and pass it to helper functions in one arg.
74  */
75 struct manstate {
76 	/* command line flags */
77 	int all;		/* -a: show all matches rather than first */
78 	int cat;		/* -c: do not use a pager */
79 	char *conffile;		/* -C: use alternate config file */
80 	int how;		/* -h: show SYNOPSIS only */
81 	char *manpath;		/* -M: alternate MANPATH */
82 	char *addpath;		/* -m: add these dirs to front of manpath */
83 	char *pathsearch;	/* -S: path of man must contain this string */
84 	char *sectionname;	/* -s: limit search to a given man section */
85 	int where;		/* -w: just show paths of all matching files */
86 
87 	/* important tags from the config file */
88 	TAG *defaultpath;	/* _default: default MANPATH */
89 	TAG *subdirs;		/* _subdir: default subdir search list */
90 	TAG *suffixlist;	/* _suffix: for files that can be cat()'d */
91 	TAG *buildlist;		/* _build: for files that must be built */
92 
93 	/* tags for internal use */
94 	TAG *intmp;		/* _intmp: tmp files we must cleanup */
95 	TAG *missinglist;	/* _missing: pages we couldn't find */
96 	TAG *mymanpath;		/* _new_path: final version of MANPATH */
97 	TAG *section;		/* <sec>: tag for m.sectionname */
98 
99 	/* other misc stuff */
100 	const char *pager;	/* pager to use */
101 	size_t pagerlen;	/* length of the above */
102 };
103 
104 /*
105  * prototypes
106  */
107 int		 main(int, char **);
108 static void	 build_page(char *, char **, struct manstate *);
109 static void	 cat(char *);
110 static const char	*check_pager(const char *);
111 static int	 cleanup(void);
112 static void	 how(char *);
113 static void	 jump(char **, char *, char *);
114 static int	 manual(char *, struct manstate *, glob_t *);
115 static void	 onsig(int);
116 static void	 usage(void);
117 
118 /*
119  * main function
120  */
121 int
122 main(int argc, char **argv)
123 {
124 	static struct manstate m = { 0 }; 	/* init to zero */
125 	int ch, abs_section, found;
126 	const char *machine;
127 	ENTRY *esubd, *epath;
128 	char *p, **ap, *cmd, buf[MAXPATHLEN * 2];
129 	size_t len;
130 	glob_t pg;
131 
132 	/*
133 	 * parse command line...
134 	 */
135 	while ((ch = getopt(argc, argv, "-aC:cfhkM:m:P:s:S:w")) != -1)
136 		switch (ch) {
137 		case 'a':
138 			m.all = 1;
139 			break;
140 		case 'C':
141 			m.conffile = optarg;
142 			break;
143 		case 'c':
144 		case '-':	/* XXX: '-' is a deprecated version of '-c' */
145 			m.cat = 1;
146 			break;
147 		case 'h':
148 			m.how = 1;
149 			break;
150 		case 'm':
151 			m.addpath = optarg;
152 			break;
153 		case 'M':
154 		case 'P':	/* -P for backward compatibility */
155 			m.manpath = strdup(optarg);
156 			break;
157 		/*
158 		 * The -f and -k options are backward compatible,
159 		 * undocumented ways of calling whatis(1) and apropos(1).
160 		 */
161 		case 'f':
162 			jump(argv, "-f", "whatis");
163 			/* NOTREACHED */
164 		case 'k':
165 			jump(argv, "-k", "apropos");
166 			/* NOTREACHED */
167 		case 's':
168 			if (m.sectionname != NULL)
169 				usage();
170 			m.sectionname = optarg;
171 			break;
172 		case 'S':
173 			m.pathsearch = optarg;
174 			break;
175 		case 'w':
176 			m.all = m.where = 1;
177 			break;
178 		case '?':
179 		default:
180 			usage();
181 		}
182 	argc -= optind;
183 	argv += optind;
184 
185 	if (!argc)
186 		usage();
187 
188 	/*
189 	 * read the configuration file and collect any other information
190 	 * we will need (machine type, pager, section [if specified
191 	 * without '-s'], and MANPATH through the environment).
192 	 */
193 	config(m.conffile);    /* exits on error ... */
194 
195 	if ((machine = getenv("MACHINE")) == NULL) {
196 		struct utsname utsname;
197 
198 		if (uname(&utsname) == -1) {
199 			perror("uname");
200 			exit(1);
201 		}
202 		machine = utsname.machine;
203 	}
204 
205 	if (!m.cat && !m.how && !m.where) {  /* if we need a pager ... */
206 		if (!isatty(STDOUT_FILENO)) {
207 			m.cat = 1;
208 		} else {
209 			if ((m.pager = getenv("PAGER")) != NULL &&
210 			    m.pager[0] != '\0')
211 				m.pager = check_pager(m.pager);
212 			else
213 				m.pager = _PATH_PAGER;
214 			m.pagerlen = strlen(m.pager);
215 		}
216 	}
217 
218 	/* do we need to set m.section to a non-null value? */
219 	if (m.sectionname) {
220 
221 		m.section = gettag(m.sectionname, 0); /* -s must be a section */
222 		if (m.section == NULL)
223 			errx(1, "unknown section: %s", m.sectionname);
224 
225 	} else if (argc > 1) {
226 
227 		m.section = gettag(*argv, 0);  /* might be a section? */
228 		if (m.section) {
229 			argv++;
230 			argc--;
231 		}
232 
233 	}
234 
235 	if (m.manpath == NULL)
236 		m.manpath = getenv("MANPATH"); /* note: -M overrides getenv */
237 
238 
239 	/*
240 	 * get default values from config file, plus create the tags we
241 	 * use for keeping internal state.  make sure all our mallocs
242 	 * go through.
243 	 */
244 	/* from cfg file */
245 	m.defaultpath = gettag("_default", 1);
246 	m.subdirs = gettag("_subdir", 1);
247 	m.suffixlist = gettag("_suffix", 1);
248 	m.buildlist = gettag("_build", 1);
249 	/* internal use */
250 	m.mymanpath = gettag("_new_path", 1);
251 	m.missinglist = gettag("_missing", 1);
252 	m.intmp = gettag("_intmp", 1);
253 	if (!m.defaultpath || !m.subdirs || !m.suffixlist || !m.buildlist ||
254 	    !m.mymanpath || !m.missinglist || !m.intmp)
255 		errx(1, "malloc failed");
256 
257 	/*
258 	 * are we using a section whose elements are all absolute paths?
259 	 * (we only need to look at the first entry on the section list,
260 	 * as config() will ensure that any additional entries will match
261 	 * the first one.)
262 	 */
263 	abs_section = (m.section != NULL &&
264 		!TAILQ_EMPTY(&m.section->entrylist) &&
265 	    		*(TAILQ_FIRST(&m.section->entrylist)->s) == '/');
266 
267 	/*
268 	 * now that we have all the data we need, we must determine the
269 	 * manpath we are going to use to find the requested entries using
270 	 * the following steps...
271 	 *
272 	 * [1] if the user specified a section and that section's elements
273 	 *     from the config file are all absolute paths, then we override
274 	 *     defaultpath and -M/MANPATH with the section's absolute paths.
275 	 */
276 	if (abs_section) {
277 		m.manpath = NULL;	   	/* ignore -M/MANPATH */
278 		m.defaultpath = m.section;	/* overwrite _default path */
279 		m.section = NULL;		/* promoted to defaultpath */
280 	}
281 
282 	/*
283 	 * [2] section can now only be non-null if the user asked for
284 	 *     a section and that section's elements did not have
285          *     absolute paths.  in this case we use the section's
286 	 *     elements to override _subdir from the config file.
287 	 *
288 	 * after this step, we are done processing "m.section"...
289 	 */
290 	if (m.section)
291 		m.subdirs = m.section;
292 
293 	/*
294 	 * [3] we need to setup the path we want to use (m.mymanpath).
295 	 *     if the user gave us a path (m.manpath) use it, otherwise
296 	 *     go with the default.   in either case we need to append
297 	 *     the subdir and machine spec to each element of the path.
298 	 *
299 	 *     for absolute section paths that come from the config file,
300 	 *     we only append the subdir spec if the path ends in
301 	 *     a '/' --- elements that do not end in '/' are assumed to
302 	 *     not have subdirectories.  this is mainly for backward compat,
303 	 *     but it allows non-subdir configs like:
304 	 *	sect3       /usr/share/man/{old/,}cat3
305 	 *	doc         /usr/{pkg,share}/doc/{sendmail/op,sendmail/intro}
306 	 *
307 	 *     note that we try and be careful to not put double slashes
308 	 *     in the path (e.g. we want /usr/share/man/man1, not
309 	 *     /usr/share/man//man1) because "more" will put the filename
310 	 *     we generate in its prompt and the double slashes look ugly.
311 	 */
312 	if (m.manpath) {
313 
314 		/* note: strtok is going to destroy m.manpath */
315 		for (p = strtok(m.manpath, ":") ; p ; p = strtok(NULL, ":")) {
316 			len = strlen(p);
317 			if (len < 1)
318 				continue;
319 			TAILQ_FOREACH(esubd, &m.subdirs->entrylist, q) {
320 				snprintf(buf, sizeof(buf), "%s%s%s{/%s,}",
321 					 p, (p[len-1] == '/') ? "" : "/",
322 					 esubd->s, machine);
323 				if (addentry(m.mymanpath, buf, 0) < 0)
324 					errx(1, "malloc failed");
325 			}
326 		}
327 
328 	} else {
329 
330 		TAILQ_FOREACH(epath, &m.defaultpath->entrylist, q) {
331 			/* handle trailing "/" magic here ... */
332 		  	if (abs_section &&
333 			    epath->s[epath->len - 1] != '/') {
334 
335 				(void)snprintf(buf, sizeof(buf),
336 				    "%s{/%s,}", epath->s, machine);
337 				if (addentry(m.mymanpath, buf, 0) < 0)
338 					errx(1, "malloc failed");
339 				continue;
340 			}
341 
342 			TAILQ_FOREACH(esubd, &m.subdirs->entrylist, q) {
343 				snprintf(buf, sizeof(buf), "%s%s%s{/%s,}",
344 					 epath->s,
345 					 (epath->s[epath->len-1] == '/') ? ""
346 									 : "/",
347 					 esubd->s, machine);
348 				if (addentry(m.mymanpath, buf, 0) < 0)
349 					errx(1, "malloc failed");
350 			}
351 		}
352 
353 	}
354 
355 	/*
356 	 * [4] finally, prepend the "-m" m.addpath to mymanpath if it
357 	 *     was specified.   subdirs and machine are always applied to
358 	 *     m.addpath.
359 	 */
360 	if (m.addpath) {
361 
362 		/* note: strtok is going to destroy m.addpath */
363 		for (p = strtok(m.addpath, ":") ; p ; p = strtok(NULL, ":")) {
364 			len = strlen(p);
365 			if (len < 1)
366 				continue;
367 			TAILQ_FOREACH(esubd, &m.subdirs->entrylist, q) {
368 				snprintf(buf, sizeof(buf), "%s%s%s{/%s,}",
369 					 p, (p[len-1] == '/') ? "" : "/",
370 					 esubd->s, machine);
371 				/* add at front */
372 				if (addentry(m.mymanpath, buf, 1) < 0)
373 					errx(1, "malloc failed");
374 			}
375 		}
376 
377 	}
378 
379 	/*
380 	 * now m.mymanpath is complete!
381 	 */
382 #if MAN_DEBUG
383 	printf("mymanpath:\n");
384 	TAILQ_FOREACH(epath, &m.mymanpath->entrylist, q) {
385 		printf("\t%s\n", epath->s);
386 	}
387 #endif
388 
389 	/*
390 	 * start searching for matching files and format them if necessary.
391 	 * setup an interrupt handler so that we can ensure that temporary
392 	 * files go away.
393 	 */
394 	(void)signal(SIGINT, onsig);
395 	(void)signal(SIGHUP, onsig);
396 	(void)signal(SIGPIPE, onsig);
397 
398 	memset(&pg, 0, sizeof(pg));
399 	for (found = 0; *argv; ++argv)
400 		if (manual(*argv, &m, &pg)) {
401 			found = 1;
402 		}
403 
404 	/* if nothing found, we're done. */
405 	if (!found) {
406 		(void)cleanup();
407 		exit (1);
408 	}
409 
410 	/*
411 	 * handle the simple display cases first (m.cat, m.how, m.where)
412 	 */
413 	if (m.cat) {
414 		for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
415 			if (**ap == '\0')
416 				continue;
417 			cat(*ap);
418 		}
419 		exit (cleanup());
420 	}
421 	if (m.how) {
422 		for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
423 			if (**ap == '\0')
424 				continue;
425 			how(*ap);
426 		}
427 		exit(cleanup());
428 	}
429 	if (m.where) {
430 		for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
431 			if (**ap == '\0')
432 				continue;
433 			(void)printf("%s\n", *ap);
434 		}
435 		exit(cleanup());
436 	}
437 
438 	/*
439 	 * normal case - we display things in a single command, so
440          * build a list of things to display.  first compute total
441 	 * length of buffer we will need so we can malloc it.
442 	 */
443 	for (ap = pg.gl_pathv, len = m.pagerlen + 1; *ap != NULL; ++ap) {
444 		if (**ap == '\0')
445 			continue;
446 		len += strlen(*ap) + 1;
447 	}
448 	if ((cmd = malloc(len)) == NULL) {
449 		warn("malloc");
450 		(void)cleanup();
451 		exit(1);
452 	}
453 
454 	/* now build the command string... */
455 	p = cmd;
456 	len = m.pagerlen;
457 	memcpy(p, m.pager, len);
458 	p += len;
459 	*p++ = ' ';
460 	for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
461 		if (**ap == '\0')
462 			continue;
463 		len = strlen(*ap);
464 		memcpy(p, *ap, len);
465 		p += len;
466 		*p++ = ' ';
467 	}
468 	*--p = '\0';
469 
470 	/* Use system(3) in case someone's pager is "pager arg1 arg2". */
471 	(void)system(cmd);
472 
473 	exit(cleanup());
474 }
475 
476 /*
477  * manual --
478  *	Search the manuals for the pages.
479  */
480 static int
481 manual(char *page, struct manstate *mp, glob_t *pg)
482 {
483 	ENTRY *suffix, *mdir;
484 	int anyfound, error, found;
485 	size_t cnt;
486 	char *p, buf[MAXPATHLEN], *escpage, *eptr;
487 	static const char escglob[] = "\\~?*{}[]";
488 
489 	anyfound = 0;
490 
491 	/*
492 	 * Fixup page which may contain glob(3) special characters, e.g.
493 	 * the famous "No man page for [" FAQ.
494 	 */
495 	if ((escpage = malloc((2 * strlen(page)) + 1)) == NULL) {
496 		warn("malloc");
497 		(void)cleanup();
498 		exit(1);
499 	}
500 
501 	p = page;
502 	eptr = escpage;
503 
504 	while (*p) {
505 		if (strchr(escglob, *p) != NULL) {
506 			*eptr++ = '\\';
507 			*eptr++ = *p++;
508 		} else
509 			*eptr++ = *p++;
510 	}
511 
512 	*eptr = '\0';
513 
514 	/* For each man directory in mymanpath ... */
515 	TAILQ_FOREACH(mdir, &mp->mymanpath->entrylist, q) {
516 
517 		/*
518 		 * use glob(3) to look in the filesystem for matching files.
519 		 * match any suffix here, as we will check that later.
520 		 */
521 		(void)snprintf(buf, sizeof(buf), "%s/%s.*", mdir->s, escpage);
522 		if ((error = glob(buf,
523 		    GLOB_APPEND | GLOB_BRACE | GLOB_NOSORT, NULL, pg)) != 0) {
524 			if (error == GLOB_NOMATCH)
525 				continue;
526 			else {
527 				warn("globbing");
528 				(void)cleanup();
529 				exit(1);
530 			}
531 		}
532 		if (pg->gl_matchc == 0)
533 			continue;
534 
535 		/*
536 		 * start going through the matches glob(3) just found and
537 		 * use m.pathsearch (if present) to filter out pages we
538 		 * don't want.  then verify the suffix is valid, and build
539 		 * the page if we have a _build suffix.
540 		 */
541 		for (cnt = pg->gl_pathc - pg->gl_matchc;
542 		    cnt < pg->gl_pathc; ++cnt) {
543 
544 			/* filter on directory path name */
545 			if (mp->pathsearch) {
546 				p = strstr(pg->gl_pathv[cnt], mp->pathsearch);
547 				if (!p || strchr(p, '/') == NULL) {
548 					pg->gl_pathv[cnt] = ""; /* zap! */
549 					continue;
550 				}
551 			}
552 
553 			/*
554 			 * Try the _suffix key words first.
555 			 *
556 			 * XXX
557 			 * Older versions of man.conf didn't have the suffix
558 			 * key words, it was assumed that everything was a .0.
559 			 * We just test for .0 first, it's fast and probably
560 			 * going to hit.
561 			 */
562 			(void)snprintf(buf, sizeof(buf), "*/%s.0", escpage);
563 			if (!fnmatch(buf, pg->gl_pathv[cnt], 0))
564 				goto next;
565 
566 			found = 0;
567 			TAILQ_FOREACH(suffix, &mp->suffixlist->entrylist, q) {
568 				(void)snprintf(buf,
569 				     sizeof(buf), "*/%s%s", escpage,
570 				     suffix->s);
571 				if (!fnmatch(buf, pg->gl_pathv[cnt], 0)) {
572 					found = 1;
573 					break;
574 				}
575 			}
576 			if (found)
577 				goto next;
578 
579 			/* Try the _build key words next. */
580 			found = 0;
581 			TAILQ_FOREACH(suffix, &mp->buildlist->entrylist, q) {
582 				for (p = suffix->s;
583 				    *p != '\0' && !isspace((unsigned char)*p);
584 				    ++p)
585 					continue;
586 				if (*p == '\0')
587 					continue;
588 				*p = '\0';
589 				(void)snprintf(buf,
590 				     sizeof(buf), "*/%s%s", escpage,
591 				     suffix->s);
592 				if (!fnmatch(buf, pg->gl_pathv[cnt], 0)) {
593 					if (!mp->where)
594 						build_page(p + 1,
595 						    &pg->gl_pathv[cnt], mp);
596 					*p = ' ';
597 					found = 1;
598 					break;
599 				}
600 				*p = ' ';
601 			}
602 			if (found) {
603 next:				anyfound = 1;
604 				if (!mp->all) {
605 					/* Delete any other matches. */
606 					while (++cnt< pg->gl_pathc)
607 						pg->gl_pathv[cnt] = "";
608 					break;
609 				}
610 				continue;
611 			}
612 
613 			/* It's not a man page, forget about it. */
614 			pg->gl_pathv[cnt] = "";
615 		}
616 
617 		if (anyfound && !mp->all)
618 			break;
619 	}
620 
621 	/* If not found, enter onto the missing list. */
622 	if (!anyfound) {
623 		if (addentry(mp->missinglist, page, 0) < 0) {
624 			warn("malloc");
625 			(void)cleanup();
626 			exit(1);
627 		}
628 	}
629 
630 	free(escpage);
631 	return (anyfound);
632 }
633 
634 /*
635  * build_page --
636  *	Build a man page for display.
637  */
638 static void
639 build_page(char *fmt, char **pathp, struct manstate *mp)
640 {
641 	static int warned;
642 	int olddir, fd, n, tmpdirlen;
643 	char *p, *b;
644 	char buf[MAXPATHLEN], cmd[MAXPATHLEN], tpath[MAXPATHLEN];
645 	const char *tmpdir;
646 
647 	/* Let the user know this may take awhile. */
648 	if (!warned) {
649 		warned = 1;
650 		warnx("Formatting manual page...");
651 	}
652 
653        /*
654         * Historically man chdir'd to the root of the man tree.
655         * This was used in man pages that contained relative ".so"
656         * directives (including other man pages for command aliases etc.)
657         * It even went one step farther, by examining the first line
658         * of the man page and parsing the .so filename so it would
659         * make hard(?) links to the cat'ted man pages for space savings.
660         * (We don't do that here, but we could).
661         */
662 
663        /* copy and find the end */
664        for (b = buf, p = *pathp; (*b++ = *p++) != '\0';)
665                continue;
666 
667 	/*
668 	 * skip the last two path components, page name and man[n] ...
669 	 * (e.g. buf will be "/usr/share/man" and p will be "man1/man.1")
670 	 * we also save a pointer to our current directory so that we
671 	 * can fchdir() back to it.  this allows relative MANDIR paths
672 	 * to work with multiple man pages... e.g. consider:
673 	 *   	cd /usr/share && man -M ./man cat ls
674 	 * when no "cat1" subdir files are present.
675 	 */
676 	olddir = -1;
677 	for (--b, --p, n = 2; b != buf; b--, p--)
678 		if (*b == '/')
679 			if (--n == 0) {
680 				*b = '\0';
681 				olddir = open(".", O_RDONLY);
682 				(void) chdir(buf);
683 				p++;
684 				break;
685 			}
686 
687 
688 	/* advance fmt pass the suffix spec to the printf format string */
689 	for (; *fmt && isspace((unsigned char)*fmt); ++fmt)
690 		continue;
691 
692 	/*
693 	 * Get a temporary file and build a version of the file
694 	 * to display.  Replace the old file name with the new one.
695 	 */
696 	if ((tmpdir = getenv("TMPDIR")) == NULL)
697 		tmpdir = _PATH_TMP;
698 	tmpdirlen = strlen(tmpdir);
699 	(void)snprintf(tpath, sizeof (tpath), "%s%s%s", tmpdir,
700 	    (tmpdirlen && tmpdir[tmpdirlen-1] == '/') ? "" : "/", TMPFILE);
701 	if ((fd = mkstemp(tpath)) == -1) {
702 		warn("%s", tpath);
703 		(void)cleanup();
704 		exit(1);
705 	}
706 	(void)snprintf(buf, sizeof(buf), "%s > %s", fmt, tpath);
707 	(void)snprintf(cmd, sizeof(cmd), buf, p);
708 	(void)system(cmd);
709 	(void)close(fd);
710 	if ((*pathp = strdup(tpath)) == NULL) {
711 		warn("malloc");
712 		(void)cleanup();
713 		exit(1);
714 	}
715 
716 	/* Link the built file into the remove-when-done list. */
717 	if (addentry(mp->intmp, *pathp, 0) < 0) {
718 		warn("malloc");
719 		(void)cleanup();
720 		exit(1);
721 	}
722 
723 	/* restore old directory so relative manpaths still work */
724 	if (olddir != -1) {
725 		fchdir(olddir);
726 		close(olddir);
727 	}
728 }
729 
730 /*
731  * how --
732  *	display how information
733  */
734 static void
735 how(char *fname)
736 {
737 	FILE *fp;
738 
739 	int lcnt, print;
740 	char *p, buf[256];
741 
742 	if (!(fp = fopen(fname, "r"))) {
743 		warn("%s", fname);
744 		(void)cleanup();
745 		exit (1);
746 	}
747 #define	S1	"SYNOPSIS"
748 #define	S2	"S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS"
749 #define	D1	"DESCRIPTION"
750 #define	D2	"D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN"
751 	for (lcnt = print = 0; fgets(buf, sizeof(buf), fp);) {
752 		if (!strncmp(buf, S1, sizeof(S1) - 1) ||
753 		    !strncmp(buf, S2, sizeof(S2) - 1)) {
754 			print = 1;
755 			continue;
756 		} else if (!strncmp(buf, D1, sizeof(D1) - 1) ||
757 		    !strncmp(buf, D2, sizeof(D2) - 1)) {
758 			if (fp)
759 				(void)fclose(fp);
760 			return;
761 		}
762 		if (!print)
763 			continue;
764 		if (*buf == '\n')
765 			++lcnt;
766 		else {
767 			for(; lcnt; --lcnt)
768 				(void)putchar('\n');
769 			for (p = buf; isspace((unsigned char)*p); ++p)
770 				continue;
771 			(void)fputs(p, stdout);
772 		}
773 	}
774 	(void)fclose(fp);
775 }
776 
777 /*
778  * cat --
779  *	cat out the file
780  */
781 static void
782 cat(char *fname)
783 {
784 	int fd, n;
785 	char buf[2048];
786 
787 	if ((fd = open(fname, O_RDONLY, 0)) < 0) {
788 		warn("%s", fname);
789 		(void)cleanup();
790 		exit(1);
791 	}
792 	while ((n = read(fd, buf, sizeof(buf))) > 0)
793 		if (write(STDOUT_FILENO, buf, n) != n) {
794 			warn("write");
795 			(void)cleanup();
796 			exit (1);
797 		}
798 	if (n == -1) {
799 		warn("read");
800 		(void)cleanup();
801 		exit(1);
802 	}
803 	(void)close(fd);
804 }
805 
806 /*
807  * check_pager --
808  *	check the user supplied page information
809  */
810 static const char *
811 check_pager(const char *name)
812 {
813 	const char *p;
814 
815 	/*
816 	 * if the user uses "more", we make it "more -s"; watch out for
817 	 * PAGER = "mypager /usr/ucb/more"
818 	 */
819 	for (p = name; *p && !isspace((unsigned char)*p); ++p)
820 		continue;
821 	for (; p > name && *p != '/'; --p);
822 	if (p != name)
823 		++p;
824 
825 	/* make sure it's "more", not "morex" */
826 	if (!strncmp(p, "more", 4) && (!p[4] || isspace((unsigned char)p[4]))){
827 		char *newname;
828 		(void)asprintf(&newname, "%s %s", p, "-s");
829 		name = newname;
830 	}
831 
832 	return (name);
833 }
834 
835 /*
836  * jump --
837  *	strip out flag argument and jump
838  */
839 static void
840 jump(char **argv, char *flag, char *name)
841 {
842 	char **arg;
843 
844 	argv[0] = name;
845 	for (arg = argv + 1; *arg; ++arg)
846 		if (!strcmp(*arg, flag))
847 			break;
848 	for (; *arg; ++arg)
849 		arg[0] = arg[1];
850 	execvp(name, argv);
851 	(void)fprintf(stderr, "%s: Command not found.\n", name);
852 	exit(1);
853 }
854 
855 /*
856  * onsig --
857  *	If signaled, delete the temporary files.
858  */
859 static void
860 onsig(int signo)
861 {
862 
863 	(void)cleanup();
864 
865 	(void)raise_default_signal(signo);
866 
867 	/* NOTREACHED */
868 	exit (1);
869 }
870 
871 /*
872  * cleanup --
873  *	Clean up temporary files, show any error messages.
874  */
875 static int
876 cleanup()
877 {
878 	TAG *intmpp, *missp;
879 	ENTRY *ep;
880 	int rval;
881 
882 	rval = 0;
883 	/*
884 	 * note that _missing and _intmp were created by main(), so
885 	 * gettag() cannot return NULL here.
886 	 */
887 	missp = gettag("_missing", 0);	/* missing man pages */
888 	intmpp = gettag("_intmp", 0);	/* tmp files we need to unlink */
889 
890 	TAILQ_FOREACH(ep, &missp->entrylist, q) {
891 		warnx("no entry for %s in the manual.", ep->s);
892 		rval = 1;
893 	}
894 
895 	TAILQ_FOREACH(ep, &intmpp->entrylist, q)
896 		(void)unlink(ep->s);
897 
898 	return (rval);
899 }
900 
901 /*
902  * usage --
903  *	print usage message and die
904  */
905 static void
906 usage()
907 {
908 	(void)fprintf(stderr, "usage: %s [-acw|-h] [-C cfg] [-M path] "
909 	    "[-m path] [-S srch] [[-s] sect] name ...\n", getprogname());
910 	(void)fprintf(stderr,
911 	    "usage: %s -k [-C cfg] [-M path] [-m path] keyword ...\n",
912 	    getprogname());
913 	exit(1);
914 }
915