xref: /openbsd-src/usr.bin/mandoc/main.c (revision 885a00aee8cfc20b2ab3631915e4284780d98155)
1 /* $OpenBSD: main.c,v 1.265 2024/03/29 01:16:30 millert Exp $ */
2 /*
3  * Copyright (c) 2010-2012, 2014-2021 Ingo Schwarze <schwarze@openbsd.org>
4  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
5  * Copyright (c) 2010 Joerg Sonnenberger <joerg@netbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  *
19  * Main program for mandoc(1), man(1), apropos(1), whatis(1), and help(1).
20  */
21 #include <sys/types.h>
22 #include <sys/ioctl.h>
23 #include <sys/param.h>	/* MACHINE */
24 #include <sys/stat.h>
25 #include <sys/wait.h>
26 
27 #include <assert.h>
28 #include <ctype.h>
29 #include <err.h>
30 #include <errno.h>
31 #include <fcntl.h>
32 #include <glob.h>
33 #include <limits.h>
34 #include <signal.h>
35 #include <stdio.h>
36 #include <stdint.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <termios.h>
40 #include <time.h>
41 #include <unistd.h>
42 
43 #include "mandoc_aux.h"
44 #include "mandoc.h"
45 #include "mandoc_xr.h"
46 #include "roff.h"
47 #include "mdoc.h"
48 #include "man.h"
49 #include "mandoc_parse.h"
50 #include "tag.h"
51 #include "term_tag.h"
52 #include "main.h"
53 #include "manconf.h"
54 #include "mansearch.h"
55 
56 #define BINM_APROPOS	"apropos"
57 #define BINM_MAN	"man"
58 #define BINM_MAKEWHATIS	"makewhatis"
59 #define BINM_WHATIS	"whatis"
60 #define OSENUM		MANDOC_OS_OPENBSD
61 
62 enum	outmode {
63 	OUTMODE_DEF = 0,
64 	OUTMODE_FLN,
65 	OUTMODE_LST,
66 	OUTMODE_ALL,
67 	OUTMODE_ONE
68 };
69 
70 enum	outt {
71 	OUTT_ASCII = 0,	/* -Tascii */
72 	OUTT_LOCALE,	/* -Tlocale */
73 	OUTT_UTF8,	/* -Tutf8 */
74 	OUTT_TREE,	/* -Ttree */
75 	OUTT_MAN,	/* -Tman */
76 	OUTT_HTML,	/* -Thtml */
77 	OUTT_MARKDOWN,	/* -Tmarkdown */
78 	OUTT_LINT,	/* -Tlint */
79 	OUTT_PS,	/* -Tps */
80 	OUTT_PDF	/* -Tpdf */
81 };
82 
83 struct	outstate {
84 	struct tag_files *tag_files;	/* Tagging state variables. */
85 	void		 *outdata;	/* data for output */
86 	int		  use_pager;
87 	int		  wstop;	/* stop after a file with a warning */
88 	int		  had_output;	/* Some output was generated. */
89 	enum outt	  outtype;	/* which output to use */
90 };
91 
92 
93 int			  mandocdb(int, char *[]);
94 
95 static	void		  check_xr(struct manpaths *);
96 static	void		  fs_append(char **, size_t, int,
97 				size_t, const char *, enum form,
98 				struct manpage **, size_t *);
99 static	int		  fs_lookup(const struct manpaths *, size_t,
100 				const char *, const char *, const char *,
101 				struct manpage **, size_t *);
102 static	int		  fs_search(const struct mansearch *,
103 				const struct manpaths *, const char *,
104 				struct manpage **, size_t *);
105 static	void		  glob_esc(char **, const char *, const char *);
106 static	void		  outdata_alloc(struct outstate *, struct manoutput *);
107 static	void		  parse(struct mparse *, int, const char *,
108 				struct outstate *, struct manconf *);
109 static	void		  passthrough(int, int);
110 static	void		  process_onefile(struct mparse *, struct manpage *,
111 				int, struct outstate *, struct manconf *);
112 static	void		  run_pager(struct outstate *, char *);
113 static	pid_t		  spawn_pager(struct outstate *, char *);
114 static	void		  usage(enum argmode) __attribute__((__noreturn__));
115 static	int		  woptions(char *, enum mandoc_os *, int *);
116 
117 static	const int sec_prios[] = {1, 4, 5, 8, 6, 3, 7, 2, 9};
118 static	char		  help_arg[] = "help";
119 static	char		 *help_argv[] = {help_arg, NULL};
120 
121 
122 int
main(int argc,char * argv[])123 main(int argc, char *argv[])
124 {
125 	struct manconf	 conf;		/* Manpaths and output options. */
126 	struct outstate	 outst;		/* Output state. */
127 	struct winsize	 ws;		/* Result of ioctl(TIOCGWINSZ). */
128 	struct mansearch search;	/* Search options. */
129 	struct manpage	*res;		/* Complete list of search results. */
130 	struct manpage	*resn;		/* Search results for one name. */
131 	struct mparse	*mp;		/* Opaque parser object. */
132 	const char	*conf_file;	/* -C: alternate config file. */
133 	const char	*os_s;		/* -I: Operating system for display. */
134 	const char	*progname, *sec, *ep;
135 	char		*defpaths;	/* -M: override manpaths. */
136 	char		*auxpaths;	/* -m: additional manpaths. */
137 	char		*oarg;		/* -O: output option string. */
138 	char		*tagarg;	/* -O tag: default value. */
139 	unsigned char	*uc;
140 	size_t		 ressz;		/* Number of elements in res[]. */
141 	size_t		 resnsz;	/* Number of elements in resn[]. */
142 	size_t		 i, ib, ssz;
143 	int		 options;	/* Parser options. */
144 	int		 show_usage;	/* Invalid argument: give up. */
145 	int		 prio, best_prio;
146 	int		 startdir;
147 	int		 c;
148 	enum mandoc_os	 os_e;		/* Check base system conventions. */
149 	enum outmode	 outmode;	/* According to command line. */
150 
151 	progname = getprogname();
152 	mandoc_msg_setoutfile(stderr);
153 	if (strncmp(progname, "mandocdb", 8) == 0 ||
154 	    strcmp(progname, BINM_MAKEWHATIS) == 0)
155 		return mandocdb(argc, argv);
156 
157 	if (pledge("stdio rpath wpath cpath tmppath tty proc exec", NULL) == -1) {
158 		mandoc_msg(MANDOCERR_PLEDGE, 0, 0, "%s", strerror(errno));
159 		return mandoc_msg_getrc();
160 	}
161 
162 	/* Search options. */
163 
164 	memset(&conf, 0, sizeof(conf));
165 	conf_file = NULL;
166 	defpaths = auxpaths = NULL;
167 
168 	memset(&search, 0, sizeof(struct mansearch));
169 	search.outkey = "Nd";
170 	oarg = NULL;
171 
172 	if (strcmp(progname, BINM_MAN) == 0)
173 		search.argmode = ARG_NAME;
174 	else if (strcmp(progname, BINM_APROPOS) == 0)
175 		search.argmode = ARG_EXPR;
176 	else if (strcmp(progname, BINM_WHATIS) == 0)
177 		search.argmode = ARG_WORD;
178 	else if (strncmp(progname, "help", 4) == 0)
179 		search.argmode = ARG_NAME;
180 	else
181 		search.argmode = ARG_FILE;
182 
183 	/* Parser options. */
184 
185 	options = MPARSE_SO | MPARSE_UTF8 | MPARSE_LATIN1;
186 	os_e = MANDOC_OS_OTHER;
187 	os_s = NULL;
188 
189 	/* Formatter options. */
190 
191 	memset(&outst, 0, sizeof(outst));
192 	outst.tag_files = NULL;
193 	outst.outtype = OUTT_LOCALE;
194 	outst.use_pager = 1;
195 
196 	show_usage = 0;
197 	outmode = OUTMODE_DEF;
198 
199 	while ((c = getopt(argc, argv,
200 	    "aC:cfhI:iK:klM:m:O:S:s:T:VW:w")) != -1) {
201 		if (c == 'i' && search.argmode == ARG_EXPR) {
202 			optind--;
203 			break;
204 		}
205 		switch (c) {
206 		case 'a':
207 			outmode = OUTMODE_ALL;
208 			break;
209 		case 'C':
210 			conf_file = optarg;
211 			break;
212 		case 'c':
213 			outst.use_pager = 0;
214 			break;
215 		case 'f':
216 			search.argmode = ARG_WORD;
217 			break;
218 		case 'h':
219 			conf.output.synopsisonly = 1;
220 			outst.use_pager = 0;
221 			outmode = OUTMODE_ALL;
222 			break;
223 		case 'I':
224 			if (strncmp(optarg, "os=", 3) != 0) {
225 				mandoc_msg(MANDOCERR_BADARG_BAD, 0, 0,
226 				    "-I %s", optarg);
227 				return mandoc_msg_getrc();
228 			}
229 			if (os_s != NULL) {
230 				mandoc_msg(MANDOCERR_BADARG_DUPE, 0, 0,
231 				    "-I %s", optarg);
232 				return mandoc_msg_getrc();
233 			}
234 			os_s = optarg + 3;
235 			break;
236 		case 'K':
237 			options &= ~(MPARSE_UTF8 | MPARSE_LATIN1);
238 			if (strcmp(optarg, "utf-8") == 0)
239 				options |=  MPARSE_UTF8;
240 			else if (strcmp(optarg, "iso-8859-1") == 0)
241 				options |=  MPARSE_LATIN1;
242 			else if (strcmp(optarg, "us-ascii") != 0) {
243 				mandoc_msg(MANDOCERR_BADARG_BAD, 0, 0,
244 				    "-K %s", optarg);
245 				return mandoc_msg_getrc();
246 			}
247 			break;
248 		case 'k':
249 			search.argmode = ARG_EXPR;
250 			break;
251 		case 'l':
252 			search.argmode = ARG_FILE;
253 			outmode = OUTMODE_ALL;
254 			break;
255 		case 'M':
256 			defpaths = optarg;
257 			break;
258 		case 'm':
259 			auxpaths = optarg;
260 			break;
261 		case 'O':
262 			oarg = optarg;
263 			break;
264 		case 'S':
265 			search.arch = optarg;
266 			break;
267 		case 's':
268 			search.sec = optarg;
269 			break;
270 		case 'T':
271 			if (strcmp(optarg, "ascii") == 0)
272 				outst.outtype = OUTT_ASCII;
273 			else if (strcmp(optarg, "lint") == 0) {
274 				outst.outtype = OUTT_LINT;
275 				mandoc_msg_setoutfile(stdout);
276 				mandoc_msg_setmin(MANDOCERR_BASE);
277 			} else if (strcmp(optarg, "tree") == 0)
278 				outst.outtype = OUTT_TREE;
279 			else if (strcmp(optarg, "man") == 0)
280 				outst.outtype = OUTT_MAN;
281 			else if (strcmp(optarg, "html") == 0)
282 				outst.outtype = OUTT_HTML;
283 			else if (strcmp(optarg, "markdown") == 0)
284 				outst.outtype = OUTT_MARKDOWN;
285 			else if (strcmp(optarg, "utf8") == 0)
286 				outst.outtype = OUTT_UTF8;
287 			else if (strcmp(optarg, "locale") == 0)
288 				outst.outtype = OUTT_LOCALE;
289 			else if (strcmp(optarg, "ps") == 0)
290 				outst.outtype = OUTT_PS;
291 			else if (strcmp(optarg, "pdf") == 0)
292 				outst.outtype = OUTT_PDF;
293 			else {
294 				mandoc_msg(MANDOCERR_BADARG_BAD, 0, 0,
295 				    "-T %s", optarg);
296 				return mandoc_msg_getrc();
297 			}
298 			break;
299 		case 'W':
300 			if (woptions(optarg, &os_e, &outst.wstop) == -1)
301 				return mandoc_msg_getrc();
302 			break;
303 		case 'w':
304 			outmode = OUTMODE_FLN;
305 			break;
306 		default:
307 			show_usage = 1;
308 			break;
309 		}
310 	}
311 
312 	if (show_usage)
313 		usage(search.argmode);
314 
315 	/* Postprocess options. */
316 
317 	switch (outmode) {
318 	case OUTMODE_DEF:
319 		switch (search.argmode) {
320 		case ARG_FILE:
321 			outmode = OUTMODE_ALL;
322 			outst.use_pager = 0;
323 			break;
324 		case ARG_NAME:
325 			outmode = OUTMODE_ONE;
326 			break;
327 		default:
328 			outmode = OUTMODE_LST;
329 			break;
330 		}
331 		break;
332 	case OUTMODE_FLN:
333 		if (search.argmode == ARG_FILE)
334 			outmode = OUTMODE_ALL;
335 		break;
336 	case OUTMODE_ALL:
337 		break;
338 	case OUTMODE_LST:
339 	case OUTMODE_ONE:
340 		abort();
341 	}
342 
343 	if (oarg != NULL) {
344 		if (outmode == OUTMODE_LST)
345 			search.outkey = oarg;
346 		else {
347 			while (oarg != NULL) {
348 				if (manconf_output(&conf.output,
349 				    strsep(&oarg, ","), 0) == -1)
350 					return mandoc_msg_getrc();
351 			}
352 		}
353 	}
354 
355 	if (outst.outtype != OUTT_TREE || conf.output.noval == 0)
356 		options |= MPARSE_VALIDATE;
357 
358 	if (outmode == OUTMODE_FLN ||
359 	    outmode == OUTMODE_LST ||
360 	    (conf.output.outfilename == NULL &&
361 	     conf.output.tagfilename == NULL &&
362 	     isatty(STDOUT_FILENO) == 0))
363 		outst.use_pager = 0;
364 
365 	if (outst.use_pager &&
366 	    (conf.output.width == 0 || conf.output.indent == 0) &&
367 	    ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1 &&
368 	    ws.ws_col > 1) {
369 		if (conf.output.width == 0 && ws.ws_col < 79)
370 			conf.output.width = ws.ws_col - 1;
371 		if (conf.output.indent == 0 && ws.ws_col < 66)
372 			conf.output.indent = 3;
373 	}
374 
375 	if (outst.use_pager == 0)
376 		c = pledge("stdio rpath", NULL);
377 	else if (conf.output.outfilename != NULL ||
378 	    conf.output.tagfilename != NULL)
379 		c = pledge("stdio rpath wpath cpath", NULL);
380 	else
381 		c = pledge("stdio rpath tmppath tty proc exec", NULL);
382 	if (c == -1) {
383 		mandoc_msg(MANDOCERR_PLEDGE, 0, 0, "%s", strerror(errno));
384 		return mandoc_msg_getrc();
385 	}
386 
387 	/* Parse arguments. */
388 
389 	if (argc > 0) {
390 		argc -= optind;
391 		argv += optind;
392 	}
393 
394 	/*
395 	 * Quirks for help(1) and man(1),
396 	 * in particular for a section argument without -s.
397 	 */
398 
399 	if (search.argmode == ARG_NAME) {
400 		if (*progname == 'h') {
401 			if (argc == 0) {
402 				argv = help_argv;
403 				argc = 1;
404 			}
405 		} else if (argc > 1 &&
406 		    ((uc = (unsigned char *)argv[0]) != NULL) &&
407 		    ((isdigit(uc[0]) && (uc[1] == '\0' ||
408 		      isalpha(uc[1]))) ||
409 		     (uc[0] == 'n' && uc[1] == '\0'))) {
410 			search.sec = (char *)uc;
411 			argv++;
412 			argc--;
413 		}
414 		if (search.arch == NULL)
415 			search.arch = getenv("MACHINE");
416 		if (search.arch == NULL)
417 			search.arch = MACHINE;
418 		if (outmode == OUTMODE_ONE)
419 			search.firstmatch = 1;
420 	}
421 
422 	/*
423 	 * Use the first argument for -O tag in addition to
424 	 * using it as a search term for man(1) or apropos(1).
425 	 */
426 
427 	if (conf.output.tag != NULL && *conf.output.tag == '\0') {
428 		tagarg = argc > 0 && search.argmode == ARG_EXPR ?
429 		    strchr(*argv, '=') : NULL;
430 		conf.output.tag = tagarg == NULL ? *argv : tagarg + 1;
431 	}
432 
433 	/* Read the configuration file. */
434 
435 	if (search.argmode != ARG_FILE ||
436 	    mandoc_msg_getmin() == MANDOCERR_STYLE)
437 		manconf_parse(&conf, conf_file, defpaths, auxpaths);
438 
439 	/* man(1): Resolve each name individually. */
440 
441 	if (search.argmode == ARG_NAME) {
442 		if (argc < 1) {
443 			if (outmode != OUTMODE_FLN)
444 				usage(ARG_NAME);
445 			if (conf.manpath.sz == 0) {
446 				warnx("The manpath is empty.");
447 				mandoc_msg_setrc(MANDOCLEVEL_BADARG);
448 			} else {
449 				for (i = 0; i + 1 < conf.manpath.sz; i++)
450 					printf("%s:", conf.manpath.paths[i]);
451 				printf("%s\n", conf.manpath.paths[i]);
452 			}
453 			manconf_free(&conf);
454 			return (int)mandoc_msg_getrc();
455 		}
456 		for (res = NULL, ressz = 0; argc > 0; argc--, argv++) {
457 			(void)mansearch(&search, &conf.manpath,
458 			    1, argv, &resn, &resnsz);
459 			if (resnsz == 0)
460 				(void)fs_search(&search, &conf.manpath,
461 				    *argv, &resn, &resnsz);
462 			if (resnsz == 0 && strchr(*argv, '/') == NULL) {
463 				if (search.arch != NULL &&
464 				    arch_valid(search.arch, OSENUM) == 0)
465 					warnx("Unknown architecture \"%s\".",
466 					    search.arch);
467 				else if (search.sec != NULL)
468 					warnx("No entry for %s in "
469 					    "section %s of the manual.",
470 					    *argv, search.sec);
471 				else
472 					warnx("No entry for %s in "
473 					    "the manual.", *argv);
474 				mandoc_msg_setrc(MANDOCLEVEL_BADARG);
475 				continue;
476 			}
477 			if (resnsz == 0) {
478 				if (access(*argv, R_OK) == -1) {
479 					mandoc_msg_setinfilename(*argv);
480 					mandoc_msg(MANDOCERR_BADARG_BAD,
481 					    0, 0, "%s", strerror(errno));
482 					mandoc_msg_setinfilename(NULL);
483 					continue;
484 				}
485 				resnsz = 1;
486 				resn = mandoc_calloc(resnsz, sizeof(*res));
487 				resn->file = mandoc_strdup(*argv);
488 				resn->ipath = SIZE_MAX;
489 				resn->form = FORM_SRC;
490 			}
491 			if (outmode != OUTMODE_ONE || resnsz == 1) {
492 				res = mandoc_reallocarray(res,
493 				    ressz + resnsz, sizeof(*res));
494 				memcpy(res + ressz, resn,
495 				    sizeof(*resn) * resnsz);
496 				ressz += resnsz;
497 				free(resn);
498 				resn = NULL;
499 				resnsz = 0;
500 				continue;
501 			}
502 
503 			/* Search for the best section. */
504 
505 			best_prio = 40;
506 			for (ib = i = 0; i < resnsz; i++) {
507 				sec = resn[i].file +
508 				    strlen(conf.manpath.paths[resn[i].ipath]);
509 				sec += strcspn(sec, "123456789");
510 				if (sec[0] == '\0')
511 					continue; /* No section at all. */
512 				prio = sec_prios[sec[0] - '1'];
513 				if (search.sec != NULL) {
514 					ssz = strlen(search.sec);
515 					if (strncmp(sec, search.sec, ssz) == 0)
516 						sec += ssz;
517 				} else
518 					sec++; /* Prefer without suffix. */
519 				if (*sec != '/')
520 					prio += 10; /* Wrong dir name. */
521 				if (search.sec != NULL) {
522 					ep = strchr(sec, '\0');
523 					if (ep - sec > 3 &&
524 					    strncmp(ep - 3, ".gz", 3) == 0)
525 						ep -= 3;
526 					if ((size_t)(ep - sec) < ssz + 3 ||
527 					    strncmp(ep - ssz, search.sec,
528 					     ssz) != 0)      /* Wrong file */
529 						prio += 20;  /* extension. */
530 				}
531 				if (prio >= best_prio)
532 					continue;
533 				best_prio = prio;
534 				ib = i;
535 			}
536 			res = mandoc_reallocarray(res, ressz + 1,
537 			    sizeof(*res));
538 			memcpy(res + ressz++, resn + ib, sizeof(*resn));
539 			memset(resn + ib, 0, sizeof(*resn));
540 			mansearch_free(resn, resnsz);
541 			resn = NULL;
542 			resnsz = 0;
543 		}
544 
545 	/* apropos(1), whatis(1): Process the full search expression. */
546 
547 	} else if (search.argmode != ARG_FILE) {
548 		if (mansearch(&search, &conf.manpath,
549 		    argc, argv, &res, &ressz) == 0)
550 			usage(search.argmode);
551 
552 		if (ressz == 0) {
553 			warnx("nothing appropriate");
554 			mandoc_msg_setrc(MANDOCLEVEL_BADARG);
555 			goto out;
556 		}
557 
558 	/* mandoc(1): Take command line arguments as file names. */
559 
560 	} else {
561 		ressz = argc > 0 ? argc : 1;
562 		res = mandoc_calloc(ressz, sizeof(*res));
563 		for (i = 0; i < ressz; i++) {
564 			if (argc > 0)
565 				res[i].file = mandoc_strdup(argv[i]);
566 			res[i].ipath = SIZE_MAX;
567 			res[i].form = FORM_SRC;
568 		}
569 	}
570 
571 	switch (outmode) {
572 	case OUTMODE_FLN:
573 		for (i = 0; i < ressz; i++)
574 			puts(res[i].file);
575 		goto out;
576 	case OUTMODE_LST:
577 		for (i = 0; i < ressz; i++)
578 			printf("%s - %s\n", res[i].names,
579 			    res[i].output == NULL ? "" :
580 			    res[i].output);
581 		goto out;
582 	default:
583 		break;
584 	}
585 
586 	if (search.argmode == ARG_FILE && auxpaths != NULL) {
587 		if (strcmp(auxpaths, "doc") == 0)
588 			options |= MPARSE_MDOC;
589 		else if (strcmp(auxpaths, "an") == 0)
590 			options |= MPARSE_MAN;
591 	}
592 
593 	mchars_alloc();
594 	mp = mparse_alloc(options, os_e, os_s);
595 
596 	/*
597 	 * Remember the original working directory, if possible.
598 	 * This will be needed if some names on the command line
599 	 * are page names and some are relative file names.
600 	 * Do not error out if the current directory is not
601 	 * readable: Maybe it won't be needed after all.
602 	 */
603 	startdir = open(".", O_RDONLY | O_DIRECTORY);
604 	for (i = 0; i < ressz; i++) {
605 		process_onefile(mp, res + i, startdir, &outst, &conf);
606 		if (outst.wstop && mandoc_msg_getrc() != MANDOCLEVEL_OK)
607 			break;
608 	}
609 	if (startdir != -1) {
610 		(void)fchdir(startdir);
611 		close(startdir);
612 	}
613 	if (conf.output.tag != NULL && conf.output.tag_found == 0) {
614 		mandoc_msg(MANDOCERR_TAG, 0, 0, "%s", conf.output.tag);
615 		conf.output.tag = NULL;
616 	}
617 	if (outst.outdata != NULL) {
618 		switch (outst.outtype) {
619 		case OUTT_HTML:
620 			html_free(outst.outdata);
621 			break;
622 		case OUTT_UTF8:
623 		case OUTT_LOCALE:
624 		case OUTT_ASCII:
625 			ascii_free(outst.outdata);
626 			break;
627 		case OUTT_PDF:
628 		case OUTT_PS:
629 			pspdf_free(outst.outdata);
630 			break;
631 		default:
632 			break;
633 		}
634 	}
635 	mandoc_xr_free();
636 	mparse_free(mp);
637 	mchars_free();
638 
639 out:
640 	mansearch_free(res, ressz);
641 	if (search.argmode != ARG_FILE)
642 		manconf_free(&conf);
643 
644 	if (outst.tag_files != NULL) {
645 		if (term_tag_close() != -1 &&
646 		    conf.output.outfilename == NULL &&
647 		    conf.output.tagfilename == NULL)
648 			run_pager(&outst, conf.output.tag);
649 		term_tag_unlink();
650 	} else if (outst.had_output && outst.outtype != OUTT_LINT)
651 		mandoc_msg_summary();
652 
653 	return (int)mandoc_msg_getrc();
654 }
655 
656 static void
usage(enum argmode argmode)657 usage(enum argmode argmode)
658 {
659 	switch (argmode) {
660 	case ARG_FILE:
661 		fputs("usage: mandoc [-ac] [-I os=name] "
662 		    "[-K encoding] [-mdoc | -man] [-O options]\n"
663 		    "\t      [-T output] [-W level] [file ...]\n", stderr);
664 		break;
665 	case ARG_NAME:
666 		fputs("usage: man [-acfhklw] [-C file] [-M path] "
667 		    "[-m path] [-S subsection]\n"
668 		    "\t   [[-s] section] name ...\n", stderr);
669 		break;
670 	case ARG_WORD:
671 		fputs("usage: whatis [-afk] [-C file] "
672 		    "[-M path] [-m path] [-O outkey] [-S arch]\n"
673 		    "\t      [-s section] name ...\n", stderr);
674 		break;
675 	case ARG_EXPR:
676 		fputs("usage: apropos [-afk] [-C file] "
677 		    "[-M path] [-m path] [-O outkey] [-S arch]\n"
678 		    "\t       [-s section] expression ...\n", stderr);
679 		break;
680 	}
681 	exit((int)MANDOCLEVEL_BADARG);
682 }
683 
684 static void
glob_esc(char ** dst,const char * src,const char * suffix)685 glob_esc(char **dst, const char *src, const char *suffix)
686 {
687 	while (*src != '\0') {
688 		if (strchr("*?[", *src) != NULL)
689 			*(*dst)++ = '\\';
690 		*(*dst)++ = *src++;
691 	}
692 	while (*suffix != '\0')
693 		*(*dst)++ = *suffix++;
694 }
695 
696 static void
fs_append(char ** file,size_t filesz,int copy,size_t ipath,const char * sec,enum form form,struct manpage ** res,size_t * ressz)697 fs_append(char **file, size_t filesz, int copy, size_t ipath,
698     const char *sec, enum form form, struct manpage **res, size_t *ressz)
699 {
700 	struct manpage	*page;
701 
702 	*res = mandoc_reallocarray(*res, *ressz + filesz, sizeof(**res));
703 	page = *res + *ressz;
704 	*ressz += filesz;
705 	for (;;) {
706 		page->file = copy ? mandoc_strdup(*file) : *file;
707 		page->names = NULL;
708 		page->output = NULL;
709 		page->bits = NAME_FILE & NAME_MASK;
710 		page->ipath = ipath;
711 		page->sec = (*sec >= '1' && *sec <= '9') ? *sec - '1' + 1 : 10;
712 		page->form = form;
713 		if (--filesz == 0)
714 			break;
715 		file++;
716 		page++;
717 	}
718 }
719 
720 static int
fs_lookup(const struct manpaths * paths,size_t ipath,const char * sec,const char * arch,const char * name,struct manpage ** res,size_t * ressz)721 fs_lookup(const struct manpaths *paths, size_t ipath,
722 	const char *sec, const char *arch, const char *name,
723 	struct manpage **res, size_t *ressz)
724 {
725 	struct stat	 sb;
726 	glob_t		 globinfo;
727 	char		*file, *cp, secnum[2];
728 	int		 globres;
729 	enum form	 form;
730 
731 	const char *const slman = "/man";
732 	const char *const slash = "/";
733 	const char *const sglob = ".[01-9]*";
734 	const char *const dot   = ".";
735 	const char *const aster = "*";
736 
737 	memset(&globinfo, 0, sizeof(globinfo));
738 	form = FORM_SRC;
739 
740 	mandoc_asprintf(&file, "%s/man%s/%s.%s",
741 	    paths->paths[ipath], sec, name, sec);
742 	if (stat(file, &sb) != -1)
743 		goto found;
744 	free(file);
745 
746 	mandoc_asprintf(&file, "%s/cat%s/%s.0",
747 	    paths->paths[ipath], sec, name);
748 	if (stat(file, &sb) != -1) {
749 		form = FORM_CAT;
750 		goto found;
751 	}
752 	free(file);
753 
754 	if (arch != NULL) {
755 		mandoc_asprintf(&file, "%s/man%s/%s/%s.%s",
756 		    paths->paths[ipath], sec, arch, name, sec);
757 		if (stat(file, &sb) != -1)
758 			goto found;
759 		free(file);
760 	}
761 
762 	cp = file = mandoc_malloc(strlen(paths->paths[ipath]) * 2 +
763 	    strlen(slman) + strlen(sec) * 2 + strlen(slash) +
764 	    strlen(name) * 2 + strlen(sglob) + 1);
765 	glob_esc(&cp, paths->paths[ipath], slman);
766 	glob_esc(&cp, sec, slash);
767 	glob_esc(&cp, name, sglob);
768 	*cp = '\0';
769 	globres = glob(file, 0, NULL, &globinfo);
770 	if (globres != 0 && globres != GLOB_NOMATCH)
771 		mandoc_msg(MANDOCERR_GLOB, 0, 0,
772 		    "%s: %s", file, strerror(errno));
773 	free(file);
774 	file = NULL;
775 	if (globres == 0)
776 		goto found;
777 	globfree(&globinfo);
778 
779 	if (sec[1] != '\0' && *ressz == 0) {
780 		secnum[0] = sec[0];
781 		secnum[1] = '\0';
782 		cp = file = mandoc_malloc(strlen(paths->paths[ipath]) * 2 +
783 		    strlen(slman) + strlen(secnum) * 2 + strlen(slash) +
784 		    strlen(name) * 2 + strlen(dot) +
785 		    strlen(sec) * 2 + strlen(aster) + 1);
786 		glob_esc(&cp, paths->paths[ipath], slman);
787 		glob_esc(&cp, secnum, slash);
788 		glob_esc(&cp, name, dot);
789 		glob_esc(&cp, sec, aster);
790 		*cp = '\0';
791 		globres = glob(file, 0, NULL, &globinfo);
792 		if (globres != 0 && globres != GLOB_NOMATCH)
793 			mandoc_msg(MANDOCERR_GLOB, 0, 0,
794 			    "%s: %s", file, strerror(errno));
795 		free(file);
796 		file = NULL;
797 		if (globres == 0)
798 			goto found;
799 		globfree(&globinfo);
800 	}
801 
802 	if (res != NULL || ipath + 1 != paths->sz)
803 		return -1;
804 
805 	mandoc_asprintf(&file, "%s.%s", name, sec);
806 	globres = stat(file, &sb);
807 	free(file);
808 	return globres;
809 
810 found:
811 	warnx("outdated mandoc.db lacks %s(%s) entry, run %s %s",
812 	    name, sec, BINM_MAKEWHATIS, paths->paths[ipath]);
813 	if (res == NULL)
814 		free(file);
815 	else if (file == NULL)
816 		fs_append(globinfo.gl_pathv, globinfo.gl_pathc, 1,
817 		    ipath, sec, form, res, ressz);
818 	else
819 		fs_append(&file, 1, 0, ipath, sec, form, res, ressz);
820 	globfree(&globinfo);
821 	return 0;
822 }
823 
824 static int
fs_search(const struct mansearch * cfg,const struct manpaths * paths,const char * name,struct manpage ** res,size_t * ressz)825 fs_search(const struct mansearch *cfg, const struct manpaths *paths,
826 	const char *name, struct manpage **res, size_t *ressz)
827 {
828 	const char *const sections[] =
829 	    {"1", "8", "6", "2", "3", "5", "7", "4", "9", "3p"};
830 	const size_t nsec = sizeof(sections)/sizeof(sections[0]);
831 
832 	size_t		 ipath, isec;
833 
834 	assert(cfg->argmode == ARG_NAME);
835 	if (res != NULL)
836 		*res = NULL;
837 	*ressz = 0;
838 	for (ipath = 0; ipath < paths->sz; ipath++) {
839 		if (cfg->sec != NULL) {
840 			if (fs_lookup(paths, ipath, cfg->sec, cfg->arch,
841 			    name, res, ressz) != -1 && cfg->firstmatch)
842 				return 0;
843 		} else {
844 			for (isec = 0; isec < nsec; isec++)
845 				if (fs_lookup(paths, ipath, sections[isec],
846 				    cfg->arch, name, res, ressz) != -1 &&
847 				    cfg->firstmatch)
848 					return 0;
849 		}
850 	}
851 	return -1;
852 }
853 
854 static void
process_onefile(struct mparse * mp,struct manpage * resp,int startdir,struct outstate * outst,struct manconf * conf)855 process_onefile(struct mparse *mp, struct manpage *resp, int startdir,
856     struct outstate *outst, struct manconf *conf)
857 {
858 	int	 fd;
859 
860 	/*
861 	 * Changing directories is not needed in ARG_FILE mode.
862 	 * Do it on a best-effort basis.  Even in case of
863 	 * failure, some functionality may still work.
864 	 */
865 	if (resp->ipath != SIZE_MAX)
866 		(void)chdir(conf->manpath.paths[resp->ipath]);
867 	else if (startdir != -1)
868 		(void)fchdir(startdir);
869 
870 	mandoc_msg_setinfilename(resp->file);
871 	if (resp->file != NULL) {
872 		if ((fd = mparse_open(mp, resp->file)) == -1) {
873 			mandoc_msg(resp->ipath == SIZE_MAX ?
874 			    MANDOCERR_BADARG_BAD : MANDOCERR_OPEN,
875 			    0, 0, "%s", strerror(errno));
876 			mandoc_msg_setinfilename(NULL);
877 			return;
878 		}
879 	} else
880 		fd = STDIN_FILENO;
881 
882 	if (outst->use_pager) {
883 		outst->use_pager = 0;
884 		outst->tag_files = term_tag_init(conf->output.outfilename,
885 		    outst->outtype == OUTT_HTML ? ".html" : "",
886 		    conf->output.tagfilename);
887 		if ((conf->output.outfilename != NULL ||
888 		     conf->output.tagfilename != NULL) &&
889 		    pledge("stdio rpath cpath", NULL) == -1) {
890 			mandoc_msg(MANDOCERR_PLEDGE, 0, 0,
891 			    "%s", strerror(errno));
892 			exit(mandoc_msg_getrc());
893 		}
894 	}
895 	if (outst->had_output && outst->outtype <= OUTT_UTF8) {
896 		if (outst->outdata == NULL)
897 			outdata_alloc(outst, &conf->output);
898 		terminal_sepline(outst->outdata);
899 	}
900 
901 	if (resp->form == FORM_SRC)
902 		parse(mp, fd, resp->file, outst, conf);
903 	else {
904 		passthrough(fd, conf->output.synopsisonly);
905 		outst->had_output = 1;
906 	}
907 
908 	if (ferror(stdout)) {
909 		if (outst->tag_files != NULL) {
910 			mandoc_msg(MANDOCERR_WRITE, 0, 0, "%s: %s",
911 			    outst->tag_files->ofn, strerror(errno));
912 			term_tag_unlink();
913 			outst->tag_files = NULL;
914 		} else
915 			mandoc_msg(MANDOCERR_WRITE, 0, 0, "%s",
916 			    strerror(errno));
917 	}
918 	mandoc_msg_setinfilename(NULL);
919 }
920 
921 static void
parse(struct mparse * mp,int fd,const char * file,struct outstate * outst,struct manconf * conf)922 parse(struct mparse *mp, int fd, const char *file,
923     struct outstate *outst, struct manconf *conf)
924 {
925 	static struct manpaths	 basepaths;
926 	static int		 previous;
927 	struct roff_meta	*meta;
928 
929 	assert(fd >= 0);
930 	if (file == NULL)
931 		file = "<stdin>";
932 
933 	if (previous)
934 		mparse_reset(mp);
935 	else
936 		previous = 1;
937 
938 	mparse_readfd(mp, fd, file);
939 	if (fd != STDIN_FILENO)
940 		close(fd);
941 
942 	/*
943 	 * With -Wstop and warnings or errors of at least the requested
944 	 * level, do not produce output.
945 	 */
946 
947 	if (outst->wstop && mandoc_msg_getrc() != MANDOCLEVEL_OK)
948 		return;
949 
950 	if (outst->outdata == NULL)
951 		outdata_alloc(outst, &conf->output);
952 	else if (outst->outtype == OUTT_HTML)
953 		html_reset(outst->outdata);
954 
955 	mandoc_xr_reset();
956 	meta = mparse_result(mp);
957 
958 	/* Execute the out device, if it exists. */
959 
960 	outst->had_output = 1;
961 	if (meta->macroset == MACROSET_MDOC) {
962 		switch (outst->outtype) {
963 		case OUTT_HTML:
964 			html_mdoc(outst->outdata, meta);
965 			break;
966 		case OUTT_TREE:
967 			tree_mdoc(outst->outdata, meta);
968 			break;
969 		case OUTT_MAN:
970 			man_mdoc(outst->outdata, meta);
971 			break;
972 		case OUTT_PDF:
973 		case OUTT_ASCII:
974 		case OUTT_UTF8:
975 		case OUTT_LOCALE:
976 		case OUTT_PS:
977 			terminal_mdoc(outst->outdata, meta);
978 			break;
979 		case OUTT_MARKDOWN:
980 			markdown_mdoc(outst->outdata, meta);
981 			break;
982 		default:
983 			break;
984 		}
985 	}
986 	if (meta->macroset == MACROSET_MAN) {
987 		switch (outst->outtype) {
988 		case OUTT_HTML:
989 			html_man(outst->outdata, meta);
990 			break;
991 		case OUTT_TREE:
992 			tree_man(outst->outdata, meta);
993 			break;
994 		case OUTT_MAN:
995 			mparse_copy(mp);
996 			break;
997 		case OUTT_PDF:
998 		case OUTT_ASCII:
999 		case OUTT_UTF8:
1000 		case OUTT_LOCALE:
1001 		case OUTT_PS:
1002 			terminal_man(outst->outdata, meta);
1003 			break;
1004 		case OUTT_MARKDOWN:
1005 			mandoc_msg(MANDOCERR_MAN_TMARKDOWN, 0, 0, NULL);
1006 			break;
1007 		default:
1008 			break;
1009 		}
1010 	}
1011 	if (conf->output.tag != NULL && conf->output.tag_found == 0 &&
1012 	    tag_exists(conf->output.tag))
1013 		conf->output.tag_found = 1;
1014 
1015 	if (mandoc_msg_getmin() < MANDOCERR_STYLE) {
1016 		if (basepaths.sz == 0)
1017 			manpath_base(&basepaths);
1018 		check_xr(&basepaths);
1019 	} else if (mandoc_msg_getmin() < MANDOCERR_WARNING)
1020 		check_xr(&conf->manpath);
1021 }
1022 
1023 static void
check_xr(struct manpaths * paths)1024 check_xr(struct manpaths *paths)
1025 {
1026 	struct mansearch	 search;
1027 	struct mandoc_xr	*xr;
1028 	size_t			 sz;
1029 
1030 	for (xr = mandoc_xr_get(); xr != NULL; xr = xr->next) {
1031 		if (xr->line == -1)
1032 			continue;
1033 		search.arch = NULL;
1034 		search.sec = xr->sec;
1035 		search.outkey = NULL;
1036 		search.argmode = ARG_NAME;
1037 		search.firstmatch = 1;
1038 		if (mansearch(&search, paths, 1, &xr->name, NULL, &sz))
1039 			continue;
1040 		if (fs_search(&search, paths, xr->name, NULL, &sz) != -1)
1041 			continue;
1042 		if (xr->count == 1)
1043 			mandoc_msg(MANDOCERR_XR_BAD, xr->line,
1044 			    xr->pos + 1, "Xr %s %s", xr->name, xr->sec);
1045 		else
1046 			mandoc_msg(MANDOCERR_XR_BAD, xr->line,
1047 			    xr->pos + 1, "Xr %s %s (%d times)",
1048 			    xr->name, xr->sec, xr->count);
1049 	}
1050 }
1051 
1052 static void
outdata_alloc(struct outstate * outst,struct manoutput * outconf)1053 outdata_alloc(struct outstate *outst, struct manoutput *outconf)
1054 {
1055 	switch (outst->outtype) {
1056 	case OUTT_HTML:
1057 		outst->outdata = html_alloc(outconf);
1058 		break;
1059 	case OUTT_UTF8:
1060 		outst->outdata = utf8_alloc(outconf);
1061 		break;
1062 	case OUTT_LOCALE:
1063 		outst->outdata = locale_alloc(outconf);
1064 		break;
1065 	case OUTT_ASCII:
1066 		outst->outdata = ascii_alloc(outconf);
1067 		break;
1068 	case OUTT_PDF:
1069 		outst->outdata = pdf_alloc(outconf);
1070 		break;
1071 	case OUTT_PS:
1072 		outst->outdata = ps_alloc(outconf);
1073 		break;
1074 	default:
1075 		break;
1076 	}
1077 }
1078 
1079 static void
passthrough(int fd,int synopsis_only)1080 passthrough(int fd, int synopsis_only)
1081 {
1082 	const char	 synb[] = "S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS";
1083 	const char	 synr[] = "SYNOPSIS";
1084 
1085 	FILE		*stream;
1086 	char		*line, *cp;
1087 	size_t		 linesz;
1088 	ssize_t		 len, written;
1089 	int		 lno, print;
1090 
1091 	stream = NULL;
1092 	line = NULL;
1093 	linesz = 0;
1094 
1095 	if (fflush(stdout) == EOF) {
1096 		mandoc_msg(MANDOCERR_FFLUSH, 0, 0, "%s", strerror(errno));
1097 		goto done;
1098 	}
1099 	if ((stream = fdopen(fd, "r")) == NULL) {
1100 		close(fd);
1101 		mandoc_msg(MANDOCERR_FDOPEN, 0, 0, "%s", strerror(errno));
1102 		goto done;
1103 	}
1104 
1105 	lno = print = 0;
1106 	while ((len = getline(&line, &linesz, stream)) != -1) {
1107 		lno++;
1108 		cp = line;
1109 		if (synopsis_only) {
1110 			if (print) {
1111 				if ( ! isspace((unsigned char)*cp))
1112 					goto done;
1113 				while (isspace((unsigned char)*cp)) {
1114 					cp++;
1115 					len--;
1116 				}
1117 			} else {
1118 				if (strcmp(cp, synb) == 0 ||
1119 				    strcmp(cp, synr) == 0)
1120 					print = 1;
1121 				continue;
1122 			}
1123 		}
1124 		for (; len > 0; len -= written) {
1125 			if ((written = write(STDOUT_FILENO, cp, len)) == -1) {
1126 				mandoc_msg(MANDOCERR_WRITE, 0, 0,
1127 				    "%s", strerror(errno));
1128 				goto done;
1129 			}
1130 		}
1131 	}
1132 	if (ferror(stream))
1133 		mandoc_msg(MANDOCERR_GETLINE, lno, 0, "%s", strerror(errno));
1134 
1135 done:
1136 	free(line);
1137 	if (stream != NULL)
1138 		fclose(stream);
1139 }
1140 
1141 static int
woptions(char * arg,enum mandoc_os * os_e,int * wstop)1142 woptions(char *arg, enum mandoc_os *os_e, int *wstop)
1143 {
1144 	char		*v, *o;
1145 	const char	*toks[11];
1146 
1147 	toks[0] = "stop";
1148 	toks[1] = "all";
1149 	toks[2] = "base";
1150 	toks[3] = "style";
1151 	toks[4] = "warning";
1152 	toks[5] = "error";
1153 	toks[6] = "unsupp";
1154 	toks[7] = "fatal";
1155 	toks[8] = "openbsd";
1156 	toks[9] = "netbsd";
1157 	toks[10] = NULL;
1158 
1159 	while (*arg) {
1160 		o = arg;
1161 		switch (getsubopt(&arg, (char * const *)toks, &v)) {
1162 		case 0:
1163 			*wstop = 1;
1164 			break;
1165 		case 1:
1166 		case 2:
1167 			mandoc_msg_setmin(MANDOCERR_BASE);
1168 			break;
1169 		case 3:
1170 			mandoc_msg_setmin(MANDOCERR_STYLE);
1171 			break;
1172 		case 4:
1173 			mandoc_msg_setmin(MANDOCERR_WARNING);
1174 			break;
1175 		case 5:
1176 			mandoc_msg_setmin(MANDOCERR_ERROR);
1177 			break;
1178 		case 6:
1179 			mandoc_msg_setmin(MANDOCERR_UNSUPP);
1180 			break;
1181 		case 7:
1182 			mandoc_msg_setmin(MANDOCERR_BADARG);
1183 			break;
1184 		case 8:
1185 			mandoc_msg_setmin(MANDOCERR_BASE);
1186 			*os_e = MANDOC_OS_OPENBSD;
1187 			break;
1188 		case 9:
1189 			mandoc_msg_setmin(MANDOCERR_BASE);
1190 			*os_e = MANDOC_OS_NETBSD;
1191 			break;
1192 		default:
1193 			mandoc_msg(MANDOCERR_BADARG_BAD, 0, 0, "-W %s", o);
1194 			return -1;
1195 		}
1196 	}
1197 	return 0;
1198 }
1199 
1200 /*
1201  * Wait until moved to the foreground,
1202  * then fork the pager and wait for the user to close it.
1203  */
1204 static void
run_pager(struct outstate * outst,char * tag_target)1205 run_pager(struct outstate *outst, char *tag_target)
1206 {
1207 	int	 signum, status;
1208 	pid_t	 man_pgid, tc_pgid;
1209 	pid_t	 pager_pid, wait_pid;
1210 
1211 	man_pgid = getpgid(0);
1212 	outst->tag_files->tcpgid =
1213 	    man_pgid == getpid() ? getpgid(getppid()) : man_pgid;
1214 	pager_pid = 0;
1215 	signum = SIGSTOP;
1216 
1217 	for (;;) {
1218 		/* Stop here until moved to the foreground. */
1219 
1220 		tc_pgid = tcgetpgrp(STDOUT_FILENO);
1221 		if (tc_pgid != man_pgid) {
1222 			if (tc_pgid == pager_pid) {
1223 				(void)tcsetpgrp(STDOUT_FILENO, man_pgid);
1224 				if (signum == SIGTTIN)
1225 					continue;
1226 			} else
1227 				outst->tag_files->tcpgid = tc_pgid;
1228 			kill(0, signum);
1229 			continue;
1230 		}
1231 
1232 		/* Once in the foreground, activate the pager. */
1233 
1234 		if (pager_pid) {
1235 			(void)tcsetpgrp(STDOUT_FILENO, pager_pid);
1236 			kill(pager_pid, SIGCONT);
1237 		} else
1238 			pager_pid = spawn_pager(outst, tag_target);
1239 
1240 		/* Wait for the pager to stop or exit. */
1241 
1242 		while ((wait_pid = waitpid(pager_pid, &status,
1243 		    WUNTRACED)) == -1 && errno == EINTR)
1244 			continue;
1245 
1246 		if (wait_pid == -1) {
1247 			mandoc_msg(MANDOCERR_WAIT, 0, 0,
1248 			    "%s", strerror(errno));
1249 			break;
1250 		}
1251 		if (!WIFSTOPPED(status))
1252 			break;
1253 
1254 		signum = WSTOPSIG(status);
1255 	}
1256 }
1257 
1258 static pid_t
spawn_pager(struct outstate * outst,char * tag_target)1259 spawn_pager(struct outstate *outst, char *tag_target)
1260 {
1261 	const struct timespec timeout = { 0, 100000000 };  /* 0.1s */
1262 #define MAX_PAGER_ARGS 16
1263 	char		*argv[MAX_PAGER_ARGS];
1264 	const char	*pager;
1265 	char		*cp;
1266 	size_t		 wordlen;
1267 	size_t		 cmdlen;
1268 	int		 argc, use_ofn;
1269 	pid_t		 pager_pid;
1270 
1271 	assert(outst->tag_files->ofd == -1);
1272 	assert(outst->tag_files->tfs == NULL);
1273 
1274 	pager = getenv("MANPAGER");
1275 	if (pager == NULL || *pager == '\0')
1276 		pager = getenv("PAGER");
1277 	if (pager == NULL || *pager == '\0')
1278 		pager = "less";
1279 
1280 	/*
1281 	 * Parse the pager command into words.
1282 	 * Intentionally do not do anything fancy here.
1283 	 */
1284 
1285 	argc = 0;
1286 	while (*pager != '\0' && argc + 5 < MAX_PAGER_ARGS) {
1287 		wordlen = strcspn(pager, " ");
1288 		argv[argc++] = mandoc_strndup(pager, wordlen);
1289 		pager += wordlen;
1290 		while (*pager == ' ')
1291 			pager++;
1292 	}
1293 
1294 	/* For more(1) and less(1), use the tag file. */
1295 
1296 	use_ofn = 1;
1297 	if (*outst->tag_files->tfn != '\0' &&
1298 	    (cmdlen = strlen(argv[0])) >= 4) {
1299 		cp = argv[0] + cmdlen - 4;
1300 		if (strcmp(cp, "less") == 0 || strcmp(cp, "more") == 0) {
1301 			argv[argc++] = mandoc_strdup("-T");
1302 			argv[argc++] = mandoc_strdup(outst->tag_files->tfn);
1303 			if (tag_target != NULL) {
1304 				argv[argc++] = mandoc_strdup("-t");
1305 				argv[argc++] = mandoc_strdup(tag_target);
1306 				use_ofn = 0;
1307 			}
1308 		}
1309 	}
1310 	if (use_ofn) {
1311 		if (outst->outtype == OUTT_HTML && tag_target != NULL)
1312 			mandoc_asprintf(&argv[argc], "file://%s#%s",
1313 			    outst->tag_files->ofn, tag_target);
1314 		else
1315 			argv[argc] = mandoc_strdup(outst->tag_files->ofn);
1316 		argc++;
1317 	}
1318 	argv[argc] = NULL;
1319 
1320 	switch (pager_pid = fork()) {
1321 	case -1:
1322 		mandoc_msg(MANDOCERR_FORK, 0, 0, "%s", strerror(errno));
1323 		exit(mandoc_msg_getrc());
1324 	case 0:
1325 		break;
1326 	default:
1327 		while (argc > 0)
1328 			free(argv[--argc]);
1329 		(void)setpgid(pager_pid, 0);
1330 		(void)tcsetpgrp(STDOUT_FILENO, pager_pid);
1331 		if (pledge("stdio rpath tmppath tty proc", NULL) == -1) {
1332 			mandoc_msg(MANDOCERR_PLEDGE, 0, 0,
1333 			    "%s", strerror(errno));
1334 			exit(mandoc_msg_getrc());
1335 		}
1336 		outst->tag_files->pager_pid = pager_pid;
1337 		return pager_pid;
1338 	}
1339 
1340 	/*
1341 	 * The child process becomes the pager.
1342 	 * Do not start it before controlling the terminal.
1343 	 */
1344 
1345 	while (tcgetpgrp(STDOUT_FILENO) != getpid())
1346 		nanosleep(&timeout, NULL);
1347 
1348 	execvp(argv[0], argv);
1349 	mandoc_msg(MANDOCERR_EXEC, 0, 0, "%s: %s", argv[0], strerror(errno));
1350 	_exit(mandoc_msg_getrc());
1351 }
1352