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man.c revision 1.33
      1 /*	$NetBSD: man.c,v 1.33 2006/04/10 14:39:06 chuck 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\n\
     36 	The Regents of the University of California.  All rights reserved.\n");
     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 1.33 2006/04/10 14:39:06 chuck 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 
     63 #include "manconf.h"
     64 #include "pathnames.h"
     65 
     66 #ifndef MAN_DEBUG
     67 #define MAN_DEBUG 0		/* debug path output */
     68 #endif
     69 
     70 /*
     71  * manstate: structure collecting the current global state so we can
     72  * easily identify it and pass it to helper functions in one arg.
     73  */
     74 struct manstate {
     75 	/* command line flags */
     76 	int all;		/* -a: show all matches rather than first */
     77 	int cat;		/* -c: do not use a pager */
     78 	char *conffile;		/* -C: use alternate config file */
     79 	int how;		/* -h: show SYNOPSIS only */
     80 	char *manpath;		/* -M: alternate MANPATH */
     81 	char *addpath;		/* -m: add these dirs to front of manpath */
     82 	char *pathsearch;	/* -S: path of man must contain this string */
     83 	char *sectionname;	/* -s: limit search to a given man section */
     84 	int where;		/* -w: just show paths of all matching files */
     85 
     86 	/* important tags from the config file */
     87 	TAG *defaultpath;	/* _default: default MANPATH */
     88 	TAG *subdirs;		/* _subdir: default subdir search list */
     89 	TAG *suffixlist;	/* _suffix: for files that can be cat()'d */
     90 	TAG *buildlist;		/* _build: for files that must be built */
     91 
     92 	/* tags for internal use */
     93 	TAG *intmp;		/* _intmp: tmp files we must cleanup */
     94 	TAG *missinglist;	/* _missing: pages we couldn't find */
     95 	TAG *mymanpath;		/* _new_path: final version of MANPATH */
     96 	TAG *section;		/* <sec>: tag for m.sectionname */
     97 
     98 	/* other misc stuff */
     99 	const char *pager;	/* pager to use */
    100 	size_t pagerlen;	/* length of the above */
    101 };
    102 
    103 /*
    104  * prototypes
    105  */
    106 int		 main(int, char **);
    107 static void	 build_page(char *, char **, struct manstate *);
    108 static void	 cat(char *);
    109 static const char	*check_pager(const char *);
    110 static int	 cleanup(void);
    111 static void	 how(char *);
    112 static void	 jump(char **, char *, char *);
    113 static int	 manual(char *, struct manstate *, glob_t *);
    114 static void	 onsig(int);
    115 static void	 usage(void);
    116 
    117 /*
    118  * main function
    119  */
    120 int
    121 main(int argc, char **argv)
    122 {
    123 	static struct manstate m = { 0 }; 	/* init to zero */
    124 	int ch, abs_section, found;
    125 	const char *machine;
    126 	ENTRY *esubd, *epath;
    127 	char *p, **ap, *cmd, buf[MAXPATHLEN * 2];
    128 	size_t len;
    129 	glob_t pg;
    130 
    131 	/*
    132 	 * parse command line...
    133 	 */
    134 	while ((ch = getopt(argc, argv, "-aC:cfhkM:m:P:s:S:w")) != -1)
    135 		switch (ch) {
    136 		case 'a':
    137 			m.all = 1;
    138 			break;
    139 		case 'C':
    140 			m.conffile = optarg;
    141 			break;
    142 		case 'c':
    143 		case '-':	/* XXX: '-' is a deprecated version of '-c' */
    144 			m.cat = 1;
    145 			break;
    146 		case 'h':
    147 			m.how = 1;
    148 			break;
    149 		case 'm':
    150 			m.addpath = optarg;
    151 			break;
    152 		case 'M':
    153 		case 'P':	/* -P for backward compatibility */
    154 			m.manpath = strdup(optarg);
    155 			break;
    156 		/*
    157 		 * The -f and -k options are backward compatible,
    158 		 * undocumented ways of calling whatis(1) and apropos(1).
    159 		 */
    160 		case 'f':
    161 			jump(argv, "-f", "whatis");
    162 			/* NOTREACHED */
    163 		case 'k':
    164 			jump(argv, "-k", "apropos");
    165 			/* NOTREACHED */
    166 		case 's':
    167 			if (m.sectionname != NULL)
    168 				usage();
    169 			m.sectionname = optarg;
    170 			break;
    171 		case 'S':
    172 			m.pathsearch = optarg;
    173 			break;
    174 		case 'w':
    175 			m.all = m.where = 1;
    176 			break;
    177 		case '?':
    178 		default:
    179 			usage();
    180 		}
    181 	argc -= optind;
    182 	argv += optind;
    183 
    184 	if (!argc)
    185 		usage();
    186 
    187 	/*
    188 	 * read the configuration file and collect any other information
    189 	 * we will need (machine type, pager, section [if specified
    190 	 * without '-s'], and MANPATH through the environment).
    191 	 */
    192 	config(m.conffile);    /* exits on error ... */
    193 
    194 	if ((machine = getenv("MACHINE")) == NULL) {
    195 		struct utsname utsname;
    196 
    197 		if (uname(&utsname) == -1) {
    198 			perror("uname");
    199 			exit(1);
    200 		}
    201 		machine = utsname.machine;
    202 	}
    203 
    204 	if (!m.cat && !m.how && !m.where) {  /* if we need a pager ... */
    205 		if (!isatty(STDOUT_FILENO)) {
    206 			m.cat = 1;
    207 		} else {
    208 			if ((m.pager = getenv("PAGER")) != NULL &&
    209 			    m.pager[0] != '\0')
    210 				m.pager = check_pager(m.pager);
    211 			else
    212 				m.pager = _PATH_PAGER;
    213 			m.pagerlen = strlen(m.pager);
    214 		}
    215 	}
    216 
    217 	/* do we need to set m.section to a non-null value? */
    218 	if (m.sectionname) {
    219 
    220 		m.section = gettag(m.sectionname, 0); /* -s must be a section */
    221 		if (m.section == NULL)
    222 			errx(1, "unknown section: %s", m.sectionname);
    223 
    224 	} else if (argc > 1) {
    225 
    226 		m.section = gettag(*argv, 0);  /* might be a section? */
    227 		if (m.section) {
    228 			argv++;
    229 			argc--;
    230 		}
    231 
    232 	}
    233 
    234 	if (m.manpath == NULL)
    235 		m.manpath = getenv("MANPATH"); /* note: -M overrides getenv */
    236 
    237 
    238 	/*
    239 	 * get default values from config file, plus create the tags we
    240 	 * use for keeping internal state.  make sure all our mallocs
    241 	 * go through.
    242 	 */
    243 	/* from cfg file */
    244 	m.defaultpath = gettag("_default", 1);
    245 	m.subdirs = gettag("_subdir", 1);
    246 	m.suffixlist = gettag("_suffix", 1);
    247 	m.buildlist = gettag("_build", 1);
    248 	/* internal use */
    249 	m.mymanpath = gettag("_new_path", 1);
    250 	m.missinglist = gettag("_missing", 1);
    251 	m.intmp = gettag("_intmp", 1);
    252 	if (!m.defaultpath || !m.subdirs || !m.suffixlist || !m.buildlist ||
    253 	    !m.mymanpath || !m.missinglist || !m.intmp)
    254 		errx(1, "malloc failed");
    255 
    256 	/*
    257 	 * are we using a section whose elements are all absolute paths?
    258 	 * (we only need to look at the first entry on the section list,
    259 	 * as config() will ensure that any additional entries will match
    260 	 * the first one.)
    261 	 */
    262 	abs_section = (m.section != NULL &&
    263 		!TAILQ_EMPTY(&m.section->entrylist) &&
    264 	    		*(TAILQ_FIRST(&m.section->entrylist)->s) == '/');
    265 
    266 	/*
    267 	 * now that we have all the data we need, we must determine the
    268 	 * manpath we are going to use to find the requested entries using
    269 	 * the following steps...
    270 	 *
    271 	 * [1] if the user specified a section and that section's elements
    272 	 *     from the config file are all absolute paths, then we override
    273 	 *     defaultpath and -M/MANPATH with the section's absolute paths.
    274 	 */
    275 	if (abs_section) {
    276 		m.manpath = NULL;	   	/* ignore -M/MANPATH */
    277 		m.defaultpath = m.section;	/* overwrite _default path */
    278 		m.section = NULL;		/* promoted to defaultpath */
    279 	}
    280 
    281 	/*
    282 	 * [2] section can now only be non-null if the user asked for
    283 	 *     a section and that section's elements did not have
    284          *     absolute paths.  in this case we use the section's
    285 	 *     elements to override _subdir from the config file.
    286 	 *
    287 	 * after this step, we are done processing "m.section"...
    288 	 */
    289 	if (m.section)
    290 		m.subdirs = m.section;
    291 
    292 	/*
    293 	 * [3] we need to setup the path we want to use (m.mymanpath).
    294 	 *     if the user gave us a path (m.manpath) use it, otherwise
    295 	 *     go with the default.   in either case we need to append
    296 	 *     the subdir and machine spec to each element of the path.
    297 	 *
    298 	 *     for absolute section paths that come from the config file,
    299 	 *     we only append the subdir spec if the path ends in
    300 	 *     a '/' --- elements that do not end in '/' are assumed to
    301 	 *     not have subdirectories.  this is mainly for backward compat,
    302 	 *     but it allows non-subdir configs like:
    303 	 *	sect3       /usr/share/man/{old/,}cat3
    304 	 *	doc         /usr/{pkg,share}/doc/{sendmail/op,sendmail/intro}
    305 	 *
    306 	 *     note that we try and be careful to not put double slashes
    307 	 *     in the path (e.g. we want /usr/share/man/man1, not
    308 	 *     /usr/share/man//man1) because "more" will put the filename
    309 	 *     we generate in its prompt and the double slashes look ugly.
    310 	 */
    311 	if (m.manpath) {
    312 
    313 		/* note: strtok is going to destroy m.manpath */
    314 		for (p = strtok(m.manpath, ":") ; p ; p = strtok(NULL, ":")) {
    315 			len = strlen(p);
    316 			if (len < 1)
    317 				continue;
    318 			TAILQ_FOREACH(esubd, &m.subdirs->entrylist, q) {
    319 				snprintf(buf, sizeof(buf), "%s%s%s{/%s,}",
    320 					 p, (p[len-1] == '/') ? "" : "/",
    321 					 esubd->s, machine);
    322 				if (addentry(m.mymanpath, buf, 0) < 0)
    323 					errx(1, "malloc failed");
    324 			}
    325 		}
    326 
    327 	} else {
    328 
    329 		TAILQ_FOREACH(epath, &m.defaultpath->entrylist, q) {
    330 			/* handle trailing "/" magic here ... */
    331 		  	if (abs_section &&
    332 			    epath->s[epath->len - 1] != '/') {
    333 
    334 				(void)snprintf(buf, sizeof(buf),
    335 				    "%s{/%s,}", epath->s, machine);
    336 				if (addentry(m.mymanpath, buf, 0) < 0)
    337 					errx(1, "malloc failed");
    338 				continue;
    339 			}
    340 
    341 			TAILQ_FOREACH(esubd, &m.subdirs->entrylist, q) {
    342 				snprintf(buf, sizeof(buf), "%s%s%s{/%s,}",
    343 					 epath->s,
    344 					 (epath->s[epath->len-1] == '/') ? ""
    345 									 : "/",
    346 					 esubd->s, machine);
    347 				if (addentry(m.mymanpath, buf, 0) < 0)
    348 					errx(1, "malloc failed");
    349 			}
    350 		}
    351 
    352 	}
    353 
    354 	/*
    355 	 * [4] finally, prepend the "-m" m.addpath to mymanpath if it
    356 	 *     was specified.   subdirs and machine are always applied to
    357 	 *     m.addpath.
    358 	 */
    359 	if (m.addpath) {
    360 
    361 		/* note: strtok is going to destroy m.addpath */
    362 		for (p = strtok(m.addpath, ":") ; p ; p = strtok(NULL, ":")) {
    363 			len = strlen(p);
    364 			if (len < 1)
    365 				continue;
    366 			TAILQ_FOREACH(esubd, &m.subdirs->entrylist, q) {
    367 				snprintf(buf, sizeof(buf), "%s%s%s{/%s,}",
    368 					 p, (p[len-1] == '/') ? "" : "/",
    369 					 esubd->s, machine);
    370 				/* add at front */
    371 				if (addentry(m.mymanpath, buf, 1) < 0)
    372 					errx(1, "malloc failed");
    373 			}
    374 		}
    375 
    376 	}
    377 
    378 	/*
    379 	 * now m.mymanpath is complete!
    380 	 */
    381 	if (MAN_DEBUG) {
    382 		printf("mymanpath:\n");
    383 		TAILQ_FOREACH(epath, &m.mymanpath->entrylist, q) {
    384 			printf("\t%s\n", epath->s);
    385 		}
    386 	}
    387 
    388 	/*
    389 	 * start searching for matching files and format them if necessary.
    390 	 * setup an interrupt handler so that we can ensure that temporary
    391 	 * files go away.
    392 	 */
    393 	(void)signal(SIGINT, onsig);
    394 	(void)signal(SIGHUP, onsig);
    395 	(void)signal(SIGPIPE, onsig);
    396 
    397 	memset(&pg, 0, sizeof(pg));
    398 	for (found = 0; *argv; ++argv)
    399 		if (manual(*argv, &m, &pg)) {
    400 			found = 1;
    401 		}
    402 
    403 	/* if nothing found, we're done. */
    404 	if (!found) {
    405 		(void)cleanup();
    406 		exit (1);
    407 	}
    408 
    409 	/*
    410 	 * handle the simple display cases first (m.cat, m.how, m.where)
    411 	 */
    412 	if (m.cat) {
    413 		for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
    414 			if (**ap == '\0')
    415 				continue;
    416 			cat(*ap);
    417 		}
    418 		exit (cleanup());
    419 	}
    420 	if (m.how) {
    421 		for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
    422 			if (**ap == '\0')
    423 				continue;
    424 			how(*ap);
    425 		}
    426 		exit(cleanup());
    427 	}
    428 	if (m.where) {
    429 		for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
    430 			if (**ap == '\0')
    431 				continue;
    432 			(void)printf("%s\n", *ap);
    433 		}
    434 		exit(cleanup());
    435 	}
    436 
    437 	/*
    438 	 * normal case - we display things in a single command, so
    439          * build a list of things to display.  first compute total
    440 	 * length of buffer we will need so we can malloc it.
    441 	 */
    442 	for (ap = pg.gl_pathv, len = m.pagerlen + 1; *ap != NULL; ++ap) {
    443 		if (**ap == '\0')
    444 			continue;
    445 		len += strlen(*ap) + 1;
    446 	}
    447 	if ((cmd = malloc(len)) == NULL) {
    448 		warn("malloc");
    449 		(void)cleanup();
    450 		exit(1);
    451 	}
    452 
    453 	/* now build the command string... */
    454 	p = cmd;
    455 	len = m.pagerlen;
    456 	memcpy(p, m.pager, len);
    457 	p += len;
    458 	*p++ = ' ';
    459 	for (ap = pg.gl_pathv; *ap != NULL; ++ap) {
    460 		if (**ap == '\0')
    461 			continue;
    462 		len = strlen(*ap);
    463 		memcpy(p, *ap, len);
    464 		p += len;
    465 		*p++ = ' ';
    466 	}
    467 	*--p = '\0';
    468 
    469 	/* Use system(3) in case someone's pager is "pager arg1 arg2". */
    470 	(void)system(cmd);
    471 
    472 	exit(cleanup());
    473 }
    474 
    475 /*
    476  * manual --
    477  *	Search the manuals for the pages.
    478  */
    479 static int
    480 manual(char *page, struct manstate *mp, glob_t *pg)
    481 {
    482 	ENTRY *suffix, *mdir;
    483 	int anyfound, error, found;
    484 	size_t cnt;
    485 	char *p, buf[MAXPATHLEN], *escpage, *eptr;
    486 	static const char escglob[] = "\\~?*{}[]";
    487 
    488 	anyfound = 0;
    489 
    490 	/*
    491 	 * Fixup page which may contain glob(3) special characters, e.g.
    492 	 * the famous "No man page for [" FAQ.
    493 	 */
    494 	if ((escpage = malloc((2 * strlen(page)) + 1)) == NULL) {
    495 		warn("malloc");
    496 		(void)cleanup();
    497 		exit(1);
    498 	}
    499 
    500 	p = page;
    501 	eptr = escpage;
    502 
    503 	while (*p) {
    504 		if (strchr(escglob, *p) != NULL) {
    505 			*eptr++ = '\\';
    506 			*eptr++ = *p++;
    507 		} else
    508 			*eptr++ = *p++;
    509 	}
    510 
    511 	*eptr = '\0';
    512 
    513 	/* For each man directory in mymanpath ... */
    514 	TAILQ_FOREACH(mdir, &mp->mymanpath->entrylist, q) {
    515 
    516 		/*
    517 		 * use glob(3) to look in the filesystem for matching files.
    518 		 * match any suffix here, as we will check that later.
    519 		 */
    520 		(void)snprintf(buf, sizeof(buf), "%s/%s.*", mdir->s, escpage);
    521 		if ((error = glob(buf,
    522 		    GLOB_APPEND | GLOB_BRACE | GLOB_NOSORT, NULL, pg)) != 0) {
    523 			if (error == GLOB_NOMATCH)
    524 				continue;
    525 			else {
    526 				warn("globbing");
    527 				(void)cleanup();
    528 				exit(1);
    529 			}
    530 		}
    531 		if (pg->gl_matchc == 0)
    532 			continue;
    533 
    534 		/*
    535 		 * start going through the matches glob(3) just found and
    536 		 * use m.pathsearch (if present) to filter out pages we
    537 		 * don't want.  then verify the suffix is valid, and build
    538 		 * the page if we have a _build suffix.
    539 		 */
    540 		for (cnt = pg->gl_pathc - pg->gl_matchc;
    541 		    cnt < pg->gl_pathc; ++cnt) {
    542 
    543 			/* filter on directory path name */
    544 			if (mp->pathsearch) {
    545 				p = strstr(pg->gl_pathv[cnt], mp->pathsearch);
    546 				if (!p || strchr(p, '/') == NULL) {
    547 					pg->gl_pathv[cnt] = ""; /* zap! */
    548 					continue;
    549 				}
    550 			}
    551 
    552 			/*
    553 			 * Try the _suffix key words first.
    554 			 *
    555 			 * XXX
    556 			 * Older versions of man.conf didn't have the suffix
    557 			 * key words, it was assumed that everything was a .0.
    558 			 * We just test for .0 first, it's fast and probably
    559 			 * going to hit.
    560 			 */
    561 			(void)snprintf(buf, sizeof(buf), "*/%s.0", escpage);
    562 			if (!fnmatch(buf, pg->gl_pathv[cnt], 0))
    563 				goto next;
    564 
    565 			found = 0;
    566 			TAILQ_FOREACH(suffix, &mp->suffixlist->entrylist, q) {
    567 				(void)snprintf(buf,
    568 				     sizeof(buf), "*/%s%s", escpage,
    569 				     suffix->s);
    570 				if (!fnmatch(buf, pg->gl_pathv[cnt], 0)) {
    571 					found = 1;
    572 					break;
    573 				}
    574 			}
    575 			if (found)
    576 				goto next;
    577 
    578 			/* Try the _build key words next. */
    579 			found = 0;
    580 			TAILQ_FOREACH(suffix, &mp->buildlist->entrylist, q) {
    581 				for (p = suffix->s;
    582 				    *p != '\0' && !isspace((unsigned char)*p);
    583 				    ++p)
    584 					continue;
    585 				if (*p == '\0')
    586 					continue;
    587 				*p = '\0';
    588 				(void)snprintf(buf,
    589 				     sizeof(buf), "*/%s%s", escpage,
    590 				     suffix->s);
    591 				if (!fnmatch(buf, pg->gl_pathv[cnt], 0)) {
    592 					if (!mp->where)
    593 						build_page(p + 1,
    594 						    &pg->gl_pathv[cnt], mp);
    595 					*p = ' ';
    596 					found = 1;
    597 					break;
    598 				}
    599 				*p = ' ';
    600 			}
    601 			if (found) {
    602 next:				anyfound = 1;
    603 				if (!mp->all) {
    604 					/* Delete any other matches. */
    605 					while (++cnt< pg->gl_pathc)
    606 						pg->gl_pathv[cnt] = "";
    607 					break;
    608 				}
    609 				continue;
    610 			}
    611 
    612 			/* It's not a man page, forget about it. */
    613 			pg->gl_pathv[cnt] = "";
    614 		}
    615 
    616 		if (anyfound && !mp->all)
    617 			break;
    618 	}
    619 
    620 	/* If not found, enter onto the missing list. */
    621 	if (!anyfound) {
    622 		if (addentry(mp->missinglist, page, 0) < 0) {
    623 			warn("malloc");
    624 			(void)cleanup();
    625 			exit(1);
    626 		}
    627 	}
    628 
    629 	free(escpage);
    630 	return (anyfound);
    631 }
    632 
    633 /*
    634  * build_page --
    635  *	Build a man page for display.
    636  */
    637 static void
    638 build_page(char *fmt, char **pathp, struct manstate *mp)
    639 {
    640 	static int warned;
    641 	int olddir, fd, n, tmpdirlen;
    642 	char *p, *b;
    643 	char buf[MAXPATHLEN], cmd[MAXPATHLEN], tpath[MAXPATHLEN];
    644 	const char *tmpdir;
    645 
    646 	/* Let the user know this may take awhile. */
    647 	if (!warned) {
    648 		warned = 1;
    649 		warnx("Formatting manual page...");
    650 	}
    651 
    652        /*
    653         * Historically man chdir'd to the root of the man tree.
    654         * This was used in man pages that contained relative ".so"
    655         * directives (including other man pages for command aliases etc.)
    656         * It even went one step farther, by examining the first line
    657         * of the man page and parsing the .so filename so it would
    658         * make hard(?) links to the cat'ted man pages for space savings.
    659         * (We don't do that here, but we could).
    660         */
    661 
    662        /* copy and find the end */
    663        for (b = buf, p = *pathp; (*b++ = *p++) != '\0';)
    664                continue;
    665 
    666 	/*
    667 	 * skip the last two path components, page name and man[n] ...
    668 	 * (e.g. buf will be "/usr/share/man" and p will be "man1/man.1")
    669 	 * we also save a pointer to our current directory so that we
    670 	 * can fchdir() back to it.  this allows relative MANDIR paths
    671 	 * to work with multiple man pages... e.g. consider:
    672 	 *   	cd /usr/share && man -M ./man cat ls
    673 	 * when no "cat1" subdir files are present.
    674 	 */
    675 	olddir = -1;
    676 	for (--b, --p, n = 2; b != buf; b--, p--)
    677 		if (*b == '/')
    678 			if (--n == 0) {
    679 				*b = '\0';
    680 				olddir = open(".", O_RDONLY);
    681 				(void) chdir(buf);
    682 				p++;
    683 				break;
    684 			}
    685 
    686 
    687 	/* advance fmt pass the suffix spec to the printf format string */
    688 	for (; *fmt && isspace((unsigned char)*fmt); ++fmt)
    689 		continue;
    690 
    691 	/*
    692 	 * Get a temporary file and build a version of the file
    693 	 * to display.  Replace the old file name with the new one.
    694 	 */
    695 	if ((tmpdir = getenv("TMPDIR")) == NULL)
    696 		tmpdir = _PATH_TMP;
    697 	tmpdirlen = strlen(tmpdir);
    698 	(void)snprintf(tpath, sizeof (tpath), "%s%s%s", tmpdir,
    699 	    (tmpdirlen && tmpdir[tmpdirlen-1] == '/') ? "" : "/", TMPFILE);
    700 	if ((fd = mkstemp(tpath)) == -1) {
    701 		warn("%s", tpath);
    702 		(void)cleanup();
    703 		exit(1);
    704 	}
    705 	(void)snprintf(buf, sizeof(buf), "%s > %s", fmt, tpath);
    706 	(void)snprintf(cmd, sizeof(cmd), buf, p);
    707 	(void)system(cmd);
    708 	(void)close(fd);
    709 	if ((*pathp = strdup(tpath)) == NULL) {
    710 		warn("malloc");
    711 		(void)cleanup();
    712 		exit(1);
    713 	}
    714 
    715 	/* Link the built file into the remove-when-done list. */
    716 	if (addentry(mp->intmp, *pathp, 0) < 0) {
    717 		warn("malloc");
    718 		(void)cleanup();
    719 		exit(1);
    720 	}
    721 
    722 	/* restore old directory so relative manpaths still work */
    723 	if (olddir != -1) {
    724 		fchdir(olddir);
    725 		close(olddir);
    726 	}
    727 }
    728 
    729 /*
    730  * how --
    731  *	display how information
    732  */
    733 static void
    734 how(char *fname)
    735 {
    736 	FILE *fp;
    737 
    738 	int lcnt, print;
    739 	char *p, buf[256];
    740 
    741 	if (!(fp = fopen(fname, "r"))) {
    742 		warn("%s", fname);
    743 		(void)cleanup();
    744 		exit (1);
    745 	}
    746 #define	S1	"SYNOPSIS"
    747 #define	S2	"S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS"
    748 #define	D1	"DESCRIPTION"
    749 #define	D2	"D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN"
    750 	for (lcnt = print = 0; fgets(buf, sizeof(buf), fp);) {
    751 		if (!strncmp(buf, S1, sizeof(S1) - 1) ||
    752 		    !strncmp(buf, S2, sizeof(S2) - 1)) {
    753 			print = 1;
    754 			continue;
    755 		} else if (!strncmp(buf, D1, sizeof(D1) - 1) ||
    756 		    !strncmp(buf, D2, sizeof(D2) - 1))
    757 			return;
    758 		if (!print)
    759 			continue;
    760 		if (*buf == '\n')
    761 			++lcnt;
    762 		else {
    763 			for(; lcnt; --lcnt)
    764 				(void)putchar('\n');
    765 			for (p = buf; isspace((unsigned char)*p); ++p)
    766 				continue;
    767 			(void)fputs(p, stdout);
    768 		}
    769 	}
    770 	(void)fclose(fp);
    771 }
    772 
    773 /*
    774  * cat --
    775  *	cat out the file
    776  */
    777 static void
    778 cat(char *fname)
    779 {
    780 	int fd, n;
    781 	char buf[2048];
    782 
    783 	if ((fd = open(fname, O_RDONLY, 0)) < 0) {
    784 		warn("%s", fname);
    785 		(void)cleanup();
    786 		exit(1);
    787 	}
    788 	while ((n = read(fd, buf, sizeof(buf))) > 0)
    789 		if (write(STDOUT_FILENO, buf, n) != n) {
    790 			warn("write");
    791 			(void)cleanup();
    792 			exit (1);
    793 		}
    794 	if (n == -1) {
    795 		warn("read");
    796 		(void)cleanup();
    797 		exit(1);
    798 	}
    799 	(void)close(fd);
    800 }
    801 
    802 /*
    803  * check_pager --
    804  *	check the user supplied page information
    805  */
    806 static const char *
    807 check_pager(const char *name)
    808 {
    809 	const char *p;
    810 
    811 	/*
    812 	 * if the user uses "more", we make it "more -s"; watch out for
    813 	 * PAGER = "mypager /usr/ucb/more"
    814 	 */
    815 	for (p = name; *p && !isspace((unsigned char)*p); ++p)
    816 		continue;
    817 	for (; p > name && *p != '/'; --p);
    818 	if (p != name)
    819 		++p;
    820 
    821 	/* make sure it's "more", not "morex" */
    822 	if (!strncmp(p, "more", 4) && (!p[4] || isspace((unsigned char)p[4]))){
    823 		char *newname;
    824 		(void)asprintf(&newname, "%s %s", p, "-s");
    825 		name = newname;
    826 	}
    827 
    828 	return (name);
    829 }
    830 
    831 /*
    832  * jump --
    833  *	strip out flag argument and jump
    834  */
    835 static void
    836 jump(char **argv, char *flag, char *name)
    837 {
    838 	char **arg;
    839 
    840 	argv[0] = name;
    841 	for (arg = argv + 1; *arg; ++arg)
    842 		if (!strcmp(*arg, flag))
    843 			break;
    844 	for (; *arg; ++arg)
    845 		arg[0] = arg[1];
    846 	execvp(name, argv);
    847 	(void)fprintf(stderr, "%s: Command not found.\n", name);
    848 	exit(1);
    849 }
    850 
    851 /*
    852  * onsig --
    853  *	If signaled, delete the temporary files.
    854  */
    855 static void
    856 onsig(int signo)
    857 {
    858 	sigset_t set;
    859 
    860 	(void)cleanup();
    861 
    862 	(void)signal(signo, SIG_DFL);
    863 
    864 	/* unblock the signal */
    865 	sigemptyset(&set);
    866 	sigaddset(&set, signo);
    867 	sigprocmask(SIG_UNBLOCK, &set, (sigset_t *) NULL);
    868 
    869 	(void)kill(getpid(), signo);
    870 
    871 	/* NOTREACHED */
    872 	exit (1);
    873 }
    874 
    875 /*
    876  * cleanup --
    877  *	Clean up temporary files, show any error messages.
    878  */
    879 static int
    880 cleanup()
    881 {
    882 	TAG *intmpp, *missp;
    883 	ENTRY *ep;
    884 	int rval;
    885 
    886 	rval = 0;
    887 	/*
    888 	 * note that _missing and _intmp were created by main(), so
    889 	 * gettag() cannot return NULL here.
    890 	 */
    891 	missp = gettag("_missing", 0);	/* missing man pages */
    892 	intmpp = gettag("_intmp", 0);	/* tmp files we need to unlink */
    893 
    894 	TAILQ_FOREACH(ep, &missp->entrylist, q) {
    895 		warnx("no entry for %s in the manual.", ep->s);
    896 		rval = 1;
    897 	}
    898 
    899 	TAILQ_FOREACH(ep, &intmpp->entrylist, q)
    900 		(void)unlink(ep->s);
    901 
    902 	return (rval);
    903 }
    904 
    905 /*
    906  * usage --
    907  *	print usage message and die
    908  */
    909 static void
    910 usage()
    911 {
    912 	(void)fprintf(stderr, "usage: %s [-acw|-h] [-C cfg] [-M path] "
    913 	    "[-m path] [-S srch] [[-s] sect] name ...\n", getprogname());
    914 	(void)fprintf(stderr,
    915 	    "usage: %s -k [-C cfg] [-M path] [-m path] keyword ...\n",
    916 	    getprogname());
    917 	exit(1);
    918 }
    919