xref: /freebsd/bin/ps/ps.c (revision 36daf0495aa68d669ac6abf004940ec1b1e83e42)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  * ------+---------+---------+-------- + --------+---------+---------+---------*
29  * Copyright (c) 2004  - Garance Alistair Drosehn <gad@FreeBSD.org>.
30  * All rights reserved.
31  *
32  * Significant modifications made to bring `ps' options somewhat closer
33  * to the standard for `ps' as described in SingleUnixSpec-v3.
34  * ------+---------+---------+-------- + --------+---------+---------+---------*
35  */
36 
37 #ifndef lint
38 static const char copyright[] =
39 "@(#) Copyright (c) 1990, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #if 0
44 #ifndef lint
45 static char sccsid[] = "@(#)ps.c	8.4 (Berkeley) 4/2/94";
46 #endif /* not lint */
47 #endif
48 
49 #include <sys/cdefs.h>
50 __FBSDID("$FreeBSD$");
51 
52 #include <sys/param.h>
53 #include <sys/proc.h>
54 #include <sys/user.h>
55 #include <sys/stat.h>
56 #include <sys/ioctl.h>
57 #include <sys/sysctl.h>
58 #include <sys/mount.h>
59 
60 #include <ctype.h>
61 #include <err.h>
62 #include <errno.h>
63 #include <fcntl.h>
64 #include <grp.h>
65 #include <kvm.h>
66 #include <limits.h>
67 #include <locale.h>
68 #include <paths.h>
69 #include <pwd.h>
70 #include <stdio.h>
71 #include <stdlib.h>
72 #include <string.h>
73 #include <unistd.h>
74 
75 #include "ps.h"
76 
77 #define	_PATH_PTS	"/dev/pts/"
78 
79 #define	W_SEP	" \t"		/* "Whitespace" list separators */
80 #define	T_SEP	","		/* "Terminate-element" list separators */
81 
82 #ifdef LAZY_PS
83 #define	DEF_UREAD	0
84 #define	OPT_LAZY_f	"f"
85 #else
86 #define	DEF_UREAD	1	/* Always do the more-expensive read. */
87 #define	OPT_LAZY_f		/* I.e., the `-f' option is not added. */
88 #endif
89 
90 /*
91  * isdigit takes an `int', but expects values in the range of unsigned char.
92  * This wrapper ensures that values from a 'char' end up in the correct range.
93  */
94 #define	isdigitch(Anychar) isdigit((u_char)(Anychar))
95 
96 int	 cflag;			/* -c */
97 int	 eval;			/* Exit value */
98 time_t	 now;			/* Current time(3) value */
99 int	 rawcpu;		/* -C */
100 int	 sumrusage;		/* -S */
101 int	 termwidth;		/* Width of the screen (0 == infinity). */
102 int	 showthreads;		/* will threads be shown? */
103 
104 struct velisthead varlist = STAILQ_HEAD_INITIALIZER(varlist);
105 
106 static int	 forceuread = DEF_UREAD; /* Do extra work to get u-area. */
107 static kvm_t	*kd;
108 static int	 needcomm;	/* -o "command" */
109 static int	 needenv;	/* -e */
110 static int	 needuser;	/* -o "user" */
111 static int	 optfatal;	/* Fatal error parsing some list-option. */
112 
113 static enum sort { DEFAULT, SORTMEM, SORTCPU } sortby = DEFAULT;
114 
115 struct listinfo;
116 typedef	int	addelem_rtn(struct listinfo *_inf, const char *_elem);
117 
118 struct listinfo {
119 	int		 count;
120 	int		 maxcount;
121 	int		 elemsize;
122 	addelem_rtn	*addelem;
123 	const char	*lname;
124 	union {
125 		gid_t	*gids;
126 		pid_t	*pids;
127 		dev_t	*ttys;
128 		uid_t	*uids;
129 		void	*ptr;
130 	} l;
131 };
132 
133 static int	 check_procfs(void);
134 static int	 addelem_gid(struct listinfo *, const char *);
135 static int	 addelem_pid(struct listinfo *, const char *);
136 static int	 addelem_tty(struct listinfo *, const char *);
137 static int	 addelem_uid(struct listinfo *, const char *);
138 static void	 add_list(struct listinfo *, const char *);
139 static void	 descendant_sort(KINFO *, int);
140 static void	 format_output(KINFO *);
141 static void	*expand_list(struct listinfo *);
142 static const char *
143 		 fmt(char **(*)(kvm_t *, const struct kinfo_proc *, int),
144 		    KINFO *, char *, int);
145 static void	 free_list(struct listinfo *);
146 static void	 init_list(struct listinfo *, addelem_rtn, int, const char *);
147 static char	*kludge_oldps_options(const char *, char *, const char *);
148 static int	 pscomp(const void *, const void *);
149 static void	 saveuser(KINFO *);
150 static void	 scanvars(void);
151 static void	 sizevars(void);
152 static void	 usage(void);
153 
154 static char dfmt[] = "pid,tt,state,time,command";
155 static char jfmt[] = "user,pid,ppid,pgid,sid,jobc,state,tt,time,command";
156 static char lfmt[] = "uid,pid,ppid,cpu,pri,nice,vsz,rss,mwchan,state,"
157 			"tt,time,command";
158 static char   o1[] = "pid";
159 static char   o2[] = "tt,state,time,command";
160 static char ufmt[] = "user,pid,%cpu,%mem,vsz,rss,tt,state,start,time,command";
161 static char vfmt[] = "pid,state,time,sl,re,pagein,vsz,rss,lim,tsiz,"
162 			"%cpu,%mem,command";
163 static char Zfmt[] = "label";
164 
165 #define	PS_ARGS	"AaCcde" OPT_LAZY_f "G:gHhjLlM:mN:O:o:p:rSTt:U:uvwXxZ"
166 
167 int
168 main(int argc, char *argv[])
169 {
170 	struct listinfo gidlist, pgrplist, pidlist;
171 	struct listinfo ruidlist, sesslist, ttylist, uidlist;
172 	struct kinfo_proc *kp;
173 	KINFO *kinfo = NULL, *next_KINFO;
174 	KINFO_STR *ks;
175 	struct varent *vent;
176 	struct winsize ws;
177 	const char *nlistf, *memf, *fmtstr, *str;
178 	char *cols;
179 	int all, ch, elem, flag, _fmt, i, lineno, linelen, left;
180 	int descendancy, nentries, nkept, nselectors;
181 	int prtheader, wflag, what, xkeep, xkeep_implied;
182 	char errbuf[_POSIX2_LINE_MAX];
183 
184 	(void) setlocale(LC_ALL, "");
185 	time(&now);			/* Used by routines in print.c. */
186 
187 	if ((cols = getenv("COLUMNS")) != NULL && *cols != '\0')
188 		termwidth = atoi(cols);
189 	else if ((ioctl(STDOUT_FILENO, TIOCGWINSZ, (char *)&ws) == -1 &&
190 	     ioctl(STDERR_FILENO, TIOCGWINSZ, (char *)&ws) == -1 &&
191 	     ioctl(STDIN_FILENO,  TIOCGWINSZ, (char *)&ws) == -1) ||
192 	     ws.ws_col == 0)
193 		termwidth = 79;
194 	else
195 		termwidth = ws.ws_col - 1;
196 
197 	/*
198 	 * Hide a number of option-processing kludges in a separate routine,
199 	 * to support some historical BSD behaviors, such as `ps axu'.
200 	 */
201 	if (argc > 1)
202 		argv[1] = kludge_oldps_options(PS_ARGS, argv[1], argv[2]);
203 
204 	all = descendancy = _fmt = nselectors = optfatal = 0;
205 	prtheader = showthreads = wflag = xkeep_implied = 0;
206 	xkeep = -1;			/* Neither -x nor -X. */
207 	init_list(&gidlist, addelem_gid, sizeof(gid_t), "group");
208 	init_list(&pgrplist, addelem_pid, sizeof(pid_t), "process group");
209 	init_list(&pidlist, addelem_pid, sizeof(pid_t), "process id");
210 	init_list(&ruidlist, addelem_uid, sizeof(uid_t), "ruser");
211 	init_list(&sesslist, addelem_pid, sizeof(pid_t), "session id");
212 	init_list(&ttylist, addelem_tty, sizeof(dev_t), "tty");
213 	init_list(&uidlist, addelem_uid, sizeof(uid_t), "user");
214 	memf = _PATH_DEVNULL;
215 	nlistf = NULL;
216 	while ((ch = getopt(argc, argv, PS_ARGS)) != -1)
217 		switch (ch) {
218 		case 'A':
219 			/*
220 			 * Exactly the same as `-ax'.   This has been
221 			 * added for compatibility with SUSv3, but for
222 			 * now it will not be described in the man page.
223 			 */
224 			nselectors++;
225 			all = xkeep = 1;
226 			break;
227 		case 'a':
228 			nselectors++;
229 			all = 1;
230 			break;
231 		case 'C':
232 			rawcpu = 1;
233 			break;
234 		case 'c':
235 			cflag = 1;
236 			break;
237 		case 'd':
238 			descendancy = 1;
239 			break;
240 		case 'e':			/* XXX set ufmt */
241 			needenv = 1;
242 			break;
243 #ifdef LAZY_PS
244 		case 'f':
245 			if (getuid() == 0 || getgid() == 0)
246 				forceuread = 1;
247 			break;
248 #endif
249 		case 'G':
250 			add_list(&gidlist, optarg);
251 			xkeep_implied = 1;
252 			nselectors++;
253 			break;
254 		case 'g':
255 #if 0
256 			/*-
257 			 * XXX - This SUSv3 behavior is still under debate
258 			 *	since it conflicts with the (undocumented)
259 			 *	`-g' option.  So we skip it for now.
260 			 */
261 			add_list(&pgrplist, optarg);
262 			xkeep_implied = 1;
263 			nselectors++;
264 			break;
265 #else
266 			/* The historical BSD-ish (from SunOS) behavior. */
267 			break;			/* no-op */
268 #endif
269 		case 'H':
270 			showthreads = KERN_PROC_INC_THREAD;
271 			break;
272 		case 'h':
273 			prtheader = ws.ws_row > 5 ? ws.ws_row : 22;
274 			break;
275 		case 'j':
276 			parsefmt(jfmt, 0);
277 			_fmt = 1;
278 			jfmt[0] = '\0';
279 			break;
280 		case 'L':
281 			showkey();
282 			exit(0);
283 		case 'l':
284 			parsefmt(lfmt, 0);
285 			_fmt = 1;
286 			lfmt[0] = '\0';
287 			break;
288 		case 'M':
289 			memf = optarg;
290 			break;
291 		case 'm':
292 			sortby = SORTMEM;
293 			break;
294 		case 'N':
295 			nlistf = optarg;
296 			break;
297 		case 'O':
298 			parsefmt(o1, 1);
299 			parsefmt(optarg, 1);
300 			parsefmt(o2, 1);
301 			o1[0] = o2[0] = '\0';
302 			_fmt = 1;
303 			break;
304 		case 'o':
305 			parsefmt(optarg, 1);
306 			_fmt = 1;
307 			break;
308 		case 'p':
309 			add_list(&pidlist, optarg);
310 			/*
311 			 * Note: `-p' does not *set* xkeep, but any values
312 			 * from pidlist are checked before xkeep is.  That
313 			 * way they are always matched, even if the user
314 			 * specifies `-X'.
315 			 */
316 			nselectors++;
317 			break;
318 #if 0
319 		case 'R':
320 			/*-
321 			 * XXX - This un-standard option is still under
322 			 *	debate.  This is what SUSv3 defines as
323 			 *	the `-U' option, and while it would be
324 			 *	nice to have, it could cause even more
325 			 *	confusion to implement it as `-R'.
326 			 */
327 			add_list(&ruidlist, optarg);
328 			xkeep_implied = 1;
329 			nselectors++;
330 			break;
331 #endif
332 		case 'r':
333 			sortby = SORTCPU;
334 			break;
335 		case 'S':
336 			sumrusage = 1;
337 			break;
338 #if 0
339 		case 's':
340 			/*-
341 			 * XXX - This non-standard option is still under
342 			 *	debate.  This *is* supported on Solaris,
343 			 *	Linux, and IRIX, but conflicts with `-s'
344 			 *	on NetBSD and maybe some older BSD's.
345 			 */
346 			add_list(&sesslist, optarg);
347 			xkeep_implied = 1;
348 			nselectors++;
349 			break;
350 #endif
351 		case 'T':
352 			if ((optarg = ttyname(STDIN_FILENO)) == NULL)
353 				errx(1, "stdin: not a terminal");
354 			/* FALLTHROUGH */
355 		case 't':
356 			add_list(&ttylist, optarg);
357 			xkeep_implied = 1;
358 			nselectors++;
359 			break;
360 		case 'U':
361 			/* This is what SUSv3 defines as the `-u' option. */
362 			add_list(&uidlist, optarg);
363 			xkeep_implied = 1;
364 			nselectors++;
365 			break;
366 		case 'u':
367 			parsefmt(ufmt, 0);
368 			sortby = SORTCPU;
369 			_fmt = 1;
370 			ufmt[0] = '\0';
371 			break;
372 		case 'v':
373 			parsefmt(vfmt, 0);
374 			sortby = SORTMEM;
375 			_fmt = 1;
376 			vfmt[0] = '\0';
377 			break;
378 		case 'w':
379 			if (wflag)
380 				termwidth = UNLIMITED;
381 			else if (termwidth < 131)
382 				termwidth = 131;
383 			wflag++;
384 			break;
385 		case 'X':
386 			/*
387 			 * Note that `-X' and `-x' are not standard "selector"
388 			 * options. For most selector-options, we check *all*
389 			 * processes to see if any are matched by the given
390 			 * value(s).  After we have a set of all the matched
391 			 * processes, then `-X' and `-x' govern whether we
392 			 * modify that *matched* set for processes which do
393 			 * not have a controlling terminal.  `-X' causes
394 			 * those processes to be deleted from the matched
395 			 * set, while `-x' causes them to be kept.
396 			 */
397 			xkeep = 0;
398 			break;
399 		case 'x':
400 			xkeep = 1;
401 			break;
402 		case 'Z':
403 			parsefmt(Zfmt, 0);
404 			Zfmt[0] = '\0';
405 			break;
406 		case '?':
407 		default:
408 			usage();
409 		}
410 	argc -= optind;
411 	argv += optind;
412 
413 	/*
414 	 * If the user specified ps -e then they want a copy of the process
415 	 * environment kvm_getenvv(3) attempts to open /proc/<pid>/mem.
416 	 * Check to make sure that procfs is mounted on /proc, otherwise
417 	 * print a warning informing the user that output will be incomplete.
418 	 */
419 	if (needenv == 1 && check_procfs() == 0)
420 		warnx("Process environment requires procfs(5)");
421 	/*
422 	 * If there arguments after processing all the options, attempt
423 	 * to treat them as a list of process ids.
424 	 */
425 	while (*argv) {
426 		if (!isdigitch(**argv))
427 			break;
428 		add_list(&pidlist, *argv);
429 		argv++;
430 	}
431 	if (*argv) {
432 		fprintf(stderr, "%s: illegal argument: %s\n",
433 		    getprogname(), *argv);
434 		usage();
435 	}
436 	if (optfatal)
437 		exit(1);		/* Error messages already printed. */
438 	if (xkeep < 0)			/* Neither -X nor -x was specified. */
439 		xkeep = xkeep_implied;
440 
441 	kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
442 	if (kd == 0)
443 		errx(1, "%s", errbuf);
444 
445 	if (!_fmt)
446 		parsefmt(dfmt, 0);
447 
448 	if (nselectors == 0) {
449 		uidlist.l.ptr = malloc(sizeof(uid_t));
450 		if (uidlist.l.ptr == NULL)
451 			errx(1, "malloc failed");
452 		nselectors = 1;
453 		uidlist.count = uidlist.maxcount = 1;
454 		*uidlist.l.uids = getuid();
455 	}
456 
457 	/*
458 	 * scan requested variables, noting what structures are needed,
459 	 * and adjusting header widths as appropriate.
460 	 */
461 	scanvars();
462 
463 	/*
464 	 * Get process list.  If the user requested just one selector-
465 	 * option, then kvm_getprocs can be asked to return just those
466 	 * processes.  Otherwise, have it return all processes, and
467 	 * then this routine will search that full list and select the
468 	 * processes which match any of the user's selector-options.
469 	 */
470 	what = showthreads != 0 ? KERN_PROC_ALL : KERN_PROC_PROC;
471 	flag = 0;
472 	if (nselectors == 1) {
473 		if (gidlist.count == 1) {
474 			what = KERN_PROC_RGID | showthreads;
475 			flag = *gidlist.l.gids;
476 			nselectors = 0;
477 		} else if (pgrplist.count == 1) {
478 			what = KERN_PROC_PGRP | showthreads;
479 			flag = *pgrplist.l.pids;
480 			nselectors = 0;
481 		} else if (pidlist.count == 1) {
482 			what = KERN_PROC_PID | showthreads;
483 			flag = *pidlist.l.pids;
484 			nselectors = 0;
485 		} else if (ruidlist.count == 1) {
486 			what = KERN_PROC_RUID | showthreads;
487 			flag = *ruidlist.l.uids;
488 			nselectors = 0;
489 		} else if (sesslist.count == 1) {
490 			what = KERN_PROC_SESSION | showthreads;
491 			flag = *sesslist.l.pids;
492 			nselectors = 0;
493 		} else if (ttylist.count == 1) {
494 			what = KERN_PROC_TTY | showthreads;
495 			flag = *ttylist.l.ttys;
496 			nselectors = 0;
497 		} else if (uidlist.count == 1) {
498 			what = KERN_PROC_UID | showthreads;
499 			flag = *uidlist.l.uids;
500 			nselectors = 0;
501 		} else if (all) {
502 			/* No need for this routine to select processes. */
503 			nselectors = 0;
504 		}
505 	}
506 
507 	/*
508 	 * select procs
509 	 */
510 	nentries = -1;
511 	kp = kvm_getprocs(kd, what, flag, &nentries);
512 	if ((kp == NULL && nentries > 0) || (kp != NULL && nentries < 0))
513 		errx(1, "%s", kvm_geterr(kd));
514 	nkept = 0;
515 	if (nentries > 0) {
516 		if ((kinfo = malloc(nentries * sizeof(*kinfo))) == NULL)
517 			errx(1, "malloc failed");
518 		for (i = nentries; --i >= 0; ++kp) {
519 			/*
520 			 * If the user specified multiple selection-criteria,
521 			 * then keep any process matched by the inclusive OR
522 			 * of all the selection-criteria given.
523 			 */
524 			if (pidlist.count > 0) {
525 				for (elem = 0; elem < pidlist.count; elem++)
526 					if (kp->ki_pid == pidlist.l.pids[elem])
527 						goto keepit;
528 			}
529 			/*
530 			 * Note that we had to process pidlist before
531 			 * filtering out processes which do not have
532 			 * a controlling terminal.
533 			 */
534 			if (xkeep == 0) {
535 				if ((kp->ki_tdev == NODEV ||
536 				    (kp->ki_flag & P_CONTROLT) == 0))
537 					continue;
538 			}
539 			if (nselectors == 0)
540 				goto keepit;
541 			if (gidlist.count > 0) {
542 				for (elem = 0; elem < gidlist.count; elem++)
543 					if (kp->ki_rgid == gidlist.l.gids[elem])
544 						goto keepit;
545 			}
546 			if (pgrplist.count > 0) {
547 				for (elem = 0; elem < pgrplist.count; elem++)
548 					if (kp->ki_pgid ==
549 					    pgrplist.l.pids[elem])
550 						goto keepit;
551 			}
552 			if (ruidlist.count > 0) {
553 				for (elem = 0; elem < ruidlist.count; elem++)
554 					if (kp->ki_ruid ==
555 					    ruidlist.l.uids[elem])
556 						goto keepit;
557 			}
558 			if (sesslist.count > 0) {
559 				for (elem = 0; elem < sesslist.count; elem++)
560 					if (kp->ki_sid == sesslist.l.pids[elem])
561 						goto keepit;
562 			}
563 			if (ttylist.count > 0) {
564 				for (elem = 0; elem < ttylist.count; elem++)
565 					if (kp->ki_tdev == ttylist.l.ttys[elem])
566 						goto keepit;
567 			}
568 			if (uidlist.count > 0) {
569 				for (elem = 0; elem < uidlist.count; elem++)
570 					if (kp->ki_uid == uidlist.l.uids[elem])
571 						goto keepit;
572 			}
573 			/*
574 			 * This process did not match any of the user's
575 			 * selector-options, so skip the process.
576 			 */
577 			continue;
578 
579 		keepit:
580 			next_KINFO = &kinfo[nkept];
581 			next_KINFO->ki_p = kp;
582 			next_KINFO->ki_d.level = 0;
583 			next_KINFO->ki_d.prefix = NULL;
584 			next_KINFO->ki_pcpu = getpcpu(next_KINFO);
585 			if (sortby == SORTMEM)
586 				next_KINFO->ki_memsize = kp->ki_tsize +
587 				    kp->ki_dsize + kp->ki_ssize;
588 			if (needuser)
589 				saveuser(next_KINFO);
590 			nkept++;
591 		}
592 	}
593 
594 	sizevars();
595 
596 	if (nkept == 0) {
597 		printheader();
598 		exit(1);
599 	}
600 
601 	/*
602 	 * sort proc list
603 	 */
604 	qsort(kinfo, nkept, sizeof(KINFO), pscomp);
605 
606 	/*
607 	 * We want things in descendant order
608 	 */
609 	if (descendancy)
610 		descendant_sort(kinfo, nkept);
611 
612 
613 	/*
614 	 * Prepare formatted output.
615 	 */
616 	for (i = 0; i < nkept; i++)
617 		format_output(&kinfo[i]);
618 
619 	/*
620 	 * Print header.
621 	 */
622 	printheader();
623 
624 	/*
625 	 * Output formatted lines.
626 	 */
627 	for (i = lineno = 0; i < nkept; i++) {
628 		linelen = 0;
629 		STAILQ_FOREACH(vent, &varlist, next_ve) {
630 	        	if (vent->var->flag & LJUST)
631 				fmtstr = "%-*s";
632 			else
633 				fmtstr = "%*s";
634 
635 			ks = STAILQ_FIRST(&kinfo[i].ki_ks);
636 			STAILQ_REMOVE_HEAD(&kinfo[i].ki_ks, ks_next);
637 			/* Truncate rightmost column if neccessary.  */
638 			if (STAILQ_NEXT(vent, next_ve) == NULL &&
639 			   termwidth != UNLIMITED && ks->ks_str != NULL) {
640 				left = termwidth - linelen;
641 				if (left > 0 && left < (int)strlen(ks->ks_str))
642 					ks->ks_str[left] = '\0';
643 			}
644 			str = ks->ks_str;
645 			if (str == NULL)
646 				str = "-";
647 			/* No padding for the last column, if it's LJUST. */
648 			if (STAILQ_NEXT(vent, next_ve) == NULL &&
649 			    vent->var->flag & LJUST)
650 				linelen += printf(fmtstr, 0, str);
651 			else
652 				linelen += printf(fmtstr, vent->var->width, str);
653 
654 			if (ks->ks_str != NULL) {
655 				free(ks->ks_str);
656 				ks->ks_str = NULL;
657 			}
658 			free(ks);
659 			ks = NULL;
660 
661 			if (STAILQ_NEXT(vent, next_ve) != NULL) {
662 				(void)putchar(' ');
663 				linelen++;
664 			}
665 		}
666 		(void)putchar('\n');
667 		if (prtheader && lineno++ == prtheader - 4) {
668 			(void)putchar('\n');
669 			printheader();
670 			lineno = 0;
671 		}
672 	}
673 	free_list(&gidlist);
674 	free_list(&pidlist);
675 	free_list(&pgrplist);
676 	free_list(&ruidlist);
677 	free_list(&sesslist);
678 	free_list(&ttylist);
679 	free_list(&uidlist);
680 	for (i = 0; i < nkept; i++)
681 		free(kinfo[i].ki_d.prefix);
682 	free(kinfo);
683 
684 	exit(eval);
685 }
686 
687 static int
688 addelem_gid(struct listinfo *inf, const char *elem)
689 {
690 	struct group *grp;
691 	const char *nameorID;
692 	char *endp;
693 	u_long bigtemp;
694 
695 	if (*elem == '\0' || strlen(elem) >= MAXLOGNAME) {
696 		if (*elem == '\0')
697 			warnx("Invalid (zero-length) %s name", inf->lname);
698 		else
699 			warnx("%s name too long: %s", inf->lname, elem);
700 		optfatal = 1;
701 		return (0);		/* Do not add this value. */
702 	}
703 
704 	/*
705 	 * SUSv3 states that `ps -G grouplist' should match "real-group
706 	 * ID numbers", and does not mention group-names.  I do want to
707 	 * also support group-names, so this tries for a group-id first,
708 	 * and only tries for a name if that doesn't work.  This is the
709 	 * opposite order of what is done in addelem_uid(), but in
710 	 * practice the order would only matter for group-names which
711 	 * are all-numeric.
712 	 */
713 	grp = NULL;
714 	nameorID = "named";
715 	errno = 0;
716 	bigtemp = strtoul(elem, &endp, 10);
717 	if (errno == 0 && *endp == '\0' && bigtemp <= GID_MAX) {
718 		nameorID = "name or ID matches";
719 		grp = getgrgid((gid_t)bigtemp);
720 	}
721 	if (grp == NULL)
722 		grp = getgrnam(elem);
723 	if (grp == NULL) {
724 		warnx("No %s %s '%s'", inf->lname, nameorID, elem);
725 		optfatal = 1;
726 		return (0);
727 	}
728 	if (inf->count >= inf->maxcount)
729 		expand_list(inf);
730 	inf->l.gids[(inf->count)++] = grp->gr_gid;
731 	return (1);
732 }
733 
734 #define	BSD_PID_MAX	99999		/* Copy of PID_MAX from sys/proc.h. */
735 static int
736 addelem_pid(struct listinfo *inf, const char *elem)
737 {
738 	char *endp;
739 	long tempid;
740 
741 	if (*elem == '\0') {
742 		warnx("Invalid (zero-length) process id");
743 		optfatal = 1;
744 		return (0);		/* Do not add this value. */
745 	}
746 
747 	errno = 0;
748 	tempid = strtol(elem, &endp, 10);
749 	if (*endp != '\0' || tempid < 0 || elem == endp) {
750 		warnx("Invalid %s: %s", inf->lname, elem);
751 		errno = ERANGE;
752 	} else if (errno != 0 || tempid > BSD_PID_MAX) {
753 		warnx("%s too large: %s", inf->lname, elem);
754 		errno = ERANGE;
755 	}
756 	if (errno == ERANGE) {
757 		optfatal = 1;
758 		return (0);
759 	}
760 	if (inf->count >= inf->maxcount)
761 		expand_list(inf);
762 	inf->l.pids[(inf->count)++] = tempid;
763 	return (1);
764 }
765 #undef	BSD_PID_MAX
766 
767 /*-
768  * The user can specify a device via one of three formats:
769  *     1) fully qualified, e.g.:     /dev/ttyp0 /dev/console	/dev/pts/0
770  *     2) missing "/dev", e.g.:      ttyp0      console		pts/0
771  *     3) two-letters, e.g.:         p0         co		0
772  *        (matching letters that would be seen in the "TT" column)
773  */
774 static int
775 addelem_tty(struct listinfo *inf, const char *elem)
776 {
777 	const char *ttypath;
778 	struct stat sb;
779 	char pathbuf[PATH_MAX], pathbuf2[PATH_MAX], pathbuf3[PATH_MAX];
780 
781 	ttypath = NULL;
782 	pathbuf2[0] = '\0';
783 	pathbuf3[0] = '\0';
784 	switch (*elem) {
785 	case '/':
786 		ttypath = elem;
787 		break;
788 	case 'c':
789 		if (strcmp(elem, "co") == 0) {
790 			ttypath = _PATH_CONSOLE;
791 			break;
792 		}
793 		/* FALLTHROUGH */
794 	default:
795 		strlcpy(pathbuf, _PATH_DEV, sizeof(pathbuf));
796 		strlcat(pathbuf, elem, sizeof(pathbuf));
797 		ttypath = pathbuf;
798 		if (strncmp(pathbuf, _PATH_TTY, strlen(_PATH_TTY)) == 0)
799 			break;
800 		if (strncmp(pathbuf, _PATH_PTS, strlen(_PATH_PTS)) == 0)
801 			break;
802 		if (strcmp(pathbuf, _PATH_CONSOLE) == 0)
803 			break;
804 		/* Check to see if /dev/tty${elem} exists */
805 		strlcpy(pathbuf2, _PATH_TTY, sizeof(pathbuf2));
806 		strlcat(pathbuf2, elem, sizeof(pathbuf2));
807 		if (stat(pathbuf2, &sb) == 0 && S_ISCHR(sb.st_mode)) {
808 			/* No need to repeat stat() && S_ISCHR() checks */
809 			ttypath = NULL;
810 			break;
811 		}
812 		/* Check to see if /dev/pts/${elem} exists */
813 		strlcpy(pathbuf3, _PATH_PTS, sizeof(pathbuf3));
814 		strlcat(pathbuf3, elem, sizeof(pathbuf3));
815 		if (stat(pathbuf3, &sb) == 0 && S_ISCHR(sb.st_mode)) {
816 			/* No need to repeat stat() && S_ISCHR() checks */
817 			ttypath = NULL;
818 			break;
819 		}
820 		break;
821 	}
822 	if (ttypath) {
823 		if (stat(ttypath, &sb) == -1) {
824 			if (pathbuf3[0] != '\0')
825 				warn("%s, %s, and %s", pathbuf3, pathbuf2,
826 				    ttypath);
827 			else
828 				warn("%s", ttypath);
829 			optfatal = 1;
830 			return (0);
831 		}
832 		if (!S_ISCHR(sb.st_mode)) {
833 			if (pathbuf3[0] != '\0')
834 				warnx("%s, %s, and %s: Not a terminal",
835 				    pathbuf3, pathbuf2, ttypath);
836 			else
837 				warnx("%s: Not a terminal", ttypath);
838 			optfatal = 1;
839 			return (0);
840 		}
841 	}
842 	if (inf->count >= inf->maxcount)
843 		expand_list(inf);
844 	inf->l.ttys[(inf->count)++] = sb.st_rdev;
845 	return (1);
846 }
847 
848 static int
849 addelem_uid(struct listinfo *inf, const char *elem)
850 {
851 	struct passwd *pwd;
852 	char *endp;
853 	u_long bigtemp;
854 
855 	if (*elem == '\0' || strlen(elem) >= MAXLOGNAME) {
856 		if (*elem == '\0')
857 			warnx("Invalid (zero-length) %s name", inf->lname);
858 		else
859 			warnx("%s name too long: %s", inf->lname, elem);
860 		optfatal = 1;
861 		return (0);		/* Do not add this value. */
862 	}
863 
864 	pwd = getpwnam(elem);
865 	if (pwd == NULL) {
866 		errno = 0;
867 		bigtemp = strtoul(elem, &endp, 10);
868 		if (errno != 0 || *endp != '\0' || bigtemp > UID_MAX)
869 			warnx("No %s named '%s'", inf->lname, elem);
870 		else {
871 			/* The string is all digits, so it might be a userID. */
872 			pwd = getpwuid((uid_t)bigtemp);
873 			if (pwd == NULL)
874 				warnx("No %s name or ID matches '%s'",
875 				    inf->lname, elem);
876 		}
877 	}
878 	if (pwd == NULL) {
879 		/*
880 		 * These used to be treated as minor warnings (and the
881 		 * option was simply ignored), but now they are fatal
882 		 * errors (and the command will be aborted).
883 		 */
884 		optfatal = 1;
885 		return (0);
886 	}
887 	if (inf->count >= inf->maxcount)
888 		expand_list(inf);
889 	inf->l.uids[(inf->count)++] = pwd->pw_uid;
890 	return (1);
891 }
892 
893 static void
894 add_list(struct listinfo *inf, const char *argp)
895 {
896 	const char *savep;
897 	char *cp, *endp;
898 	int toolong;
899 	char elemcopy[PATH_MAX];
900 
901 	if (*argp == 0)
902 		inf->addelem(inf, elemcopy);
903 	while (*argp != '\0') {
904 		while (*argp != '\0' && strchr(W_SEP, *argp) != NULL)
905 			argp++;
906 		savep = argp;
907 		toolong = 0;
908 		cp = elemcopy;
909 		if (strchr(T_SEP, *argp) == NULL) {
910 			endp = elemcopy + sizeof(elemcopy) - 1;
911 			while (*argp != '\0' && cp <= endp &&
912 			    strchr(W_SEP T_SEP, *argp) == NULL)
913 				*cp++ = *argp++;
914 			if (cp > endp)
915 				toolong = 1;
916 		}
917 		if (!toolong) {
918 			*cp = '\0';
919 			/*
920 			 * Add this single element to the given list.
921 			 */
922 			inf->addelem(inf, elemcopy);
923 		} else {
924 			/*
925 			 * The string is too long to copy.  Find the end
926 			 * of the string to print out the warning message.
927 			 */
928 			while (*argp != '\0' && strchr(W_SEP T_SEP,
929 			    *argp) == NULL)
930 				argp++;
931 			warnx("Value too long: %.*s", (int)(argp - savep),
932 			    savep);
933 			optfatal = 1;
934 		}
935 		/*
936 		 * Skip over any number of trailing whitespace characters,
937 		 * but only one (at most) trailing element-terminating
938 		 * character.
939 		 */
940 		while (*argp != '\0' && strchr(W_SEP, *argp) != NULL)
941 			argp++;
942 		if (*argp != '\0' && strchr(T_SEP, *argp) != NULL) {
943 			argp++;
944 			/* Catch case where string ended with a comma. */
945 			if (*argp == '\0')
946 				inf->addelem(inf, argp);
947 		}
948 	}
949 }
950 
951 static void
952 descendant_sort(KINFO *ki, int items)
953 {
954 	int dst, lvl, maxlvl, n, ndst, nsrc, siblings, src;
955 	unsigned char *path;
956 	KINFO kn;
957 
958 	/*
959 	 * First, sort the entries by descendancy, tracking the descendancy
960 	 * depth in the ki_d.level field.
961 	 */
962 	src = 0;
963 	maxlvl = 0;
964 	while (src < items) {
965 		if (ki[src].ki_d.level) {
966 			src++;
967 			continue;
968 		}
969 		for (nsrc = 1; src + nsrc < items; nsrc++)
970 			if (!ki[src + nsrc].ki_d.level)
971 				break;
972 
973 		for (dst = 0; dst < items; dst++) {
974 			if (ki[dst].ki_p->ki_pid == ki[src].ki_p->ki_pid)
975 				continue;
976 			if (ki[dst].ki_p->ki_pid == ki[src].ki_p->ki_ppid)
977 				break;
978 		}
979 
980 		if (dst == items) {
981 			src += nsrc;
982 			continue;
983 		}
984 
985 		for (ndst = 1; dst + ndst < items; ndst++)
986 			if (ki[dst + ndst].ki_d.level <= ki[dst].ki_d.level)
987 				break;
988 
989 		for (n = src; n < src + nsrc; n++) {
990 			ki[n].ki_d.level += ki[dst].ki_d.level + 1;
991 			if (maxlvl < ki[n].ki_d.level)
992 				maxlvl = ki[n].ki_d.level;
993 		}
994 
995 		while (nsrc) {
996 			if (src < dst) {
997 				kn = ki[src];
998 				memmove(ki + src, ki + src + 1,
999 				    (dst - src + ndst - 1) * sizeof *ki);
1000 				ki[dst + ndst - 1] = kn;
1001 				nsrc--;
1002 				dst--;
1003 				ndst++;
1004 			} else if (src != dst + ndst) {
1005 				kn = ki[src];
1006 				memmove(ki + dst + ndst + 1, ki + dst + ndst,
1007 				    (src - dst - ndst) * sizeof *ki);
1008 				ki[dst + ndst] = kn;
1009 				ndst++;
1010 				nsrc--;
1011 				src++;
1012 			} else {
1013 				ndst += nsrc;
1014 				src += nsrc;
1015 				nsrc = 0;
1016 			}
1017 		}
1018 	}
1019 
1020 	/*
1021 	 * Now populate ki_d.prefix (instead of ki_d.level) with the command
1022 	 * prefix used to show descendancies.
1023 	 */
1024 	path = malloc((maxlvl + 7) / 8);
1025 	memset(path, '\0', (maxlvl + 7) / 8);
1026 	for (src = 0; src < items; src++) {
1027 		if ((lvl = ki[src].ki_d.level) == 0) {
1028 			ki[src].ki_d.prefix = NULL;
1029 			continue;
1030 		}
1031 		if ((ki[src].ki_d.prefix = malloc(lvl * 2 + 1)) == NULL)
1032 			errx(1, "malloc failed");
1033 		for (n = 0; n < lvl - 2; n++) {
1034 			ki[src].ki_d.prefix[n * 2] =
1035 			    path[n / 8] & 1 << (n % 8) ? '|' : ' ';
1036 			ki[src].ki_d.prefix[n * 2 + 1] = ' ';
1037 		}
1038 		if (n == lvl - 2) {
1039 			/* Have I any more siblings? */
1040 			for (siblings = 0, dst = src + 1; dst < items; dst++) {
1041 				if (ki[dst].ki_d.level > lvl)
1042 					continue;
1043 				if (ki[dst].ki_d.level == lvl)
1044 					siblings = 1;
1045 				break;
1046 			}
1047 			if (siblings)
1048 				path[n / 8] |= 1 << (n % 8);
1049 			else
1050 				path[n / 8] &= ~(1 << (n % 8));
1051 			ki[src].ki_d.prefix[n * 2] = siblings ? '|' : '`';
1052 			ki[src].ki_d.prefix[n * 2 + 1] = '-';
1053 			n++;
1054 		}
1055 		strcpy(ki[src].ki_d.prefix + n * 2, "- ");
1056 	}
1057 	free(path);
1058 }
1059 
1060 static void *
1061 expand_list(struct listinfo *inf)
1062 {
1063 	void *newlist;
1064 	int newmax;
1065 
1066 	newmax = (inf->maxcount + 1) << 1;
1067 	newlist = realloc(inf->l.ptr, newmax * inf->elemsize);
1068 	if (newlist == NULL) {
1069 		free(inf->l.ptr);
1070 		errx(1, "realloc to %d %ss failed", newmax, inf->lname);
1071 	}
1072 	inf->maxcount = newmax;
1073 	inf->l.ptr = newlist;
1074 
1075 	return (newlist);
1076 }
1077 
1078 static void
1079 free_list(struct listinfo *inf)
1080 {
1081 
1082 	inf->count = inf->elemsize = inf->maxcount = 0;
1083 	if (inf->l.ptr != NULL)
1084 		free(inf->l.ptr);
1085 	inf->addelem = NULL;
1086 	inf->lname = NULL;
1087 	inf->l.ptr = NULL;
1088 }
1089 
1090 static void
1091 init_list(struct listinfo *inf, addelem_rtn artn, int elemsize,
1092     const char *lname)
1093 {
1094 
1095 	inf->count = inf->maxcount = 0;
1096 	inf->elemsize = elemsize;
1097 	inf->addelem = artn;
1098 	inf->lname = lname;
1099 	inf->l.ptr = NULL;
1100 }
1101 
1102 VARENT *
1103 find_varentry(VAR *v)
1104 {
1105 	struct varent *vent;
1106 
1107 	STAILQ_FOREACH(vent, &varlist, next_ve) {
1108 		if (strcmp(vent->var->name, v->name) == 0)
1109 			return vent;
1110 	}
1111 	return NULL;
1112 }
1113 
1114 static void
1115 scanvars(void)
1116 {
1117 	struct varent *vent;
1118 	VAR *v;
1119 
1120 	STAILQ_FOREACH(vent, &varlist, next_ve) {
1121 		v = vent->var;
1122 		if (v->flag & USER)
1123 			needuser = 1;
1124 		if (v->flag & COMM)
1125 			needcomm = 1;
1126 	}
1127 }
1128 
1129 static void
1130 format_output(KINFO *ki)
1131 {
1132 	struct varent *vent;
1133 	VAR *v;
1134 	KINFO_STR *ks;
1135 	char *str;
1136 	int len;
1137 
1138 	STAILQ_INIT(&ki->ki_ks);
1139 	STAILQ_FOREACH(vent, &varlist, next_ve) {
1140 		v = vent->var;
1141 		str = (v->oproc)(ki, vent);
1142 		ks = malloc(sizeof(*ks));
1143 		if (ks == NULL)
1144 			errx(1, "malloc failed");
1145 		ks->ks_str = str;
1146 		STAILQ_INSERT_TAIL(&ki->ki_ks, ks, ks_next);
1147 		if (str != NULL) {
1148 			len = strlen(str);
1149 		} else
1150 			len = 1; /* "-" */
1151 		if (v->width < len)
1152 			v->width = len;
1153 	}
1154 }
1155 
1156 static void
1157 sizevars(void)
1158 {
1159 	struct varent *vent;
1160 	VAR *v;
1161 	int i;
1162 
1163 	STAILQ_FOREACH(vent, &varlist, next_ve) {
1164 		v = vent->var;
1165 		i = strlen(vent->header);
1166 		if (v->width < i)
1167 			v->width = i;
1168 	}
1169 }
1170 
1171 static const char *
1172 fmt(char **(*fn)(kvm_t *, const struct kinfo_proc *, int), KINFO *ki,
1173     char *comm, int maxlen)
1174 {
1175 	const char *s;
1176 
1177 	s = fmt_argv((*fn)(kd, ki->ki_p, termwidth), comm, maxlen);
1178 	return (s);
1179 }
1180 
1181 #define UREADOK(ki)	(forceuread || (ki->ki_p->ki_flag & P_INMEM))
1182 
1183 static void
1184 saveuser(KINFO *ki)
1185 {
1186 
1187 	if (ki->ki_p->ki_flag & P_INMEM) {
1188 		/*
1189 		 * The u-area might be swapped out, and we can't get
1190 		 * at it because we have a crashdump and no swap.
1191 		 * If it's here fill in these fields, otherwise, just
1192 		 * leave them 0.
1193 		 */
1194 		ki->ki_valid = 1;
1195 	} else
1196 		ki->ki_valid = 0;
1197 	/*
1198 	 * save arguments if needed
1199 	 */
1200 	if (needcomm) {
1201 		if (ki->ki_p->ki_stat == SZOMB)
1202 			ki->ki_args = strdup("<defunct>");
1203 		else if (UREADOK(ki) || (ki->ki_p->ki_args != NULL))
1204 			ki->ki_args = strdup(fmt(kvm_getargv, ki,
1205 			    ki->ki_p->ki_comm, MAXCOMLEN));
1206 		else
1207 			asprintf(&ki->ki_args, "(%s)", ki->ki_p->ki_comm);
1208 		if (ki->ki_args == NULL)
1209 			errx(1, "malloc failed");
1210 	} else {
1211 		ki->ki_args = NULL;
1212 	}
1213 	if (needenv) {
1214 		if (UREADOK(ki))
1215 			ki->ki_env = strdup(fmt(kvm_getenvv, ki,
1216 			    (char *)NULL, 0));
1217 		else
1218 			ki->ki_env = strdup("()");
1219 		if (ki->ki_env == NULL)
1220 			errx(1, "malloc failed");
1221 	} else {
1222 		ki->ki_env = NULL;
1223 	}
1224 }
1225 
1226 /* A macro used to improve the readability of pscomp(). */
1227 #define	DIFF_RETURN(a, b, field) do {	\
1228 	if ((a)->field != (b)->field)	\
1229 		return (((a)->field < (b)->field) ? -1 : 1); 	\
1230 } while (0)
1231 
1232 static int
1233 pscomp(const void *a, const void *b)
1234 {
1235 	const KINFO *ka, *kb;
1236 
1237 	ka = a;
1238 	kb = b;
1239 	/* SORTCPU and SORTMEM are sorted in descending order. */
1240 	if (sortby == SORTCPU)
1241 		DIFF_RETURN(kb, ka, ki_pcpu);
1242 	if (sortby == SORTMEM)
1243 		DIFF_RETURN(kb, ka, ki_memsize);
1244 	/*
1245 	 * TTY's are sorted in ascending order, except that all NODEV
1246 	 * processes come before all processes with a device.
1247 	 */
1248 	if (ka->ki_p->ki_tdev != kb->ki_p->ki_tdev) {
1249 		if (ka->ki_p->ki_tdev == NODEV)
1250 			return (-1);
1251 		if (kb->ki_p->ki_tdev == NODEV)
1252 			return (1);
1253 		DIFF_RETURN(ka, kb, ki_p->ki_tdev);
1254 	}
1255 
1256 	/* PID's and TID's (threads) are sorted in ascending order. */
1257 	DIFF_RETURN(ka, kb, ki_p->ki_pid);
1258 	DIFF_RETURN(ka, kb, ki_p->ki_tid);
1259 	return (0);
1260 }
1261 #undef DIFF_RETURN
1262 
1263 /*
1264  * ICK (all for getopt), would rather hide the ugliness
1265  * here than taint the main code.
1266  *
1267  *  ps foo -> ps -foo
1268  *  ps 34 -> ps -p34
1269  *
1270  * The old convention that 't' with no trailing tty arg means the users
1271  * tty, is only supported if argv[1] doesn't begin with a '-'.  This same
1272  * feature is available with the option 'T', which takes no argument.
1273  */
1274 static char *
1275 kludge_oldps_options(const char *optlist, char *origval, const char *nextarg)
1276 {
1277 	size_t len;
1278 	char *argp, *cp, *newopts, *ns, *optp, *pidp;
1279 
1280 	/*
1281 	 * See if the original value includes any option which takes an
1282 	 * argument (and will thus use up the remainder of the string).
1283 	 */
1284 	argp = NULL;
1285 	if (optlist != NULL) {
1286 		for (cp = origval; *cp != '\0'; cp++) {
1287 			optp = strchr(optlist, *cp);
1288 			if ((optp != NULL) && *(optp + 1) == ':') {
1289 				argp = cp;
1290 				break;
1291 			}
1292 		}
1293 	}
1294 	if (argp != NULL && *origval == '-')
1295 		return (origval);
1296 
1297 	/*
1298 	 * if last letter is a 't' flag with no argument (in the context
1299 	 * of the oldps options -- option string NOT starting with a '-' --
1300 	 * then convert to 'T' (meaning *this* terminal, i.e. ttyname(0)).
1301 	 *
1302 	 * However, if a flag accepting a string argument is found earlier
1303 	 * in the option string (including a possible `t' flag), then the
1304 	 * remainder of the string must be the argument to that flag; so
1305 	 * do not modify that argument.  Note that a trailing `t' would
1306 	 * cause argp to be set, if argp was not already set by some
1307 	 * earlier option.
1308 	 */
1309 	len = strlen(origval);
1310 	cp = origval + len - 1;
1311 	pidp = NULL;
1312 	if (*cp == 't' && *origval != '-' && cp == argp) {
1313 		if (nextarg == NULL || *nextarg == '-' || isdigitch(*nextarg))
1314 			*cp = 'T';
1315 	} else if (argp == NULL) {
1316 		/*
1317 		 * The original value did not include any option which takes
1318 		 * an argument (and that would include `p' and `t'), so check
1319 		 * the value for trailing number, or comma-separated list of
1320 		 * numbers, which we will treat as a pid request.
1321 		 */
1322 		if (isdigitch(*cp)) {
1323 			while (cp >= origval && (*cp == ',' || isdigitch(*cp)))
1324 				--cp;
1325 			pidp = cp + 1;
1326 		}
1327 	}
1328 
1329 	/*
1330 	 * If nothing needs to be added to the string, then return
1331 	 * the "original" (although possibly modified) value.
1332 	 */
1333 	if (*origval == '-' && pidp == NULL)
1334 		return (origval);
1335 
1336 	/*
1337 	 * Create a copy of the string to add '-' and/or 'p' to the
1338 	 * original value.
1339 	 */
1340 	if ((newopts = ns = malloc(len + 3)) == NULL)
1341 		errx(1, "malloc failed");
1342 
1343 	if (*origval != '-')
1344 		*ns++ = '-';	/* add option flag */
1345 
1346 	if (pidp == NULL)
1347 		strcpy(ns, origval);
1348 	else {
1349 		/*
1350 		 * Copy everything before the pid string, add the `p',
1351 		 * and then copy the pid string.
1352 		 */
1353 		len = pidp - origval;
1354 		memcpy(ns, origval, len);
1355 		ns += len;
1356 		*ns++ = 'p';
1357 		strcpy(ns, pidp);
1358 	}
1359 
1360 	return (newopts);
1361 }
1362 
1363 static int
1364 check_procfs(void)
1365 {
1366 	struct statfs mnt;
1367 
1368 	if (statfs("/proc", &mnt) < 0)
1369 		return (0);
1370 	if (strcmp(mnt.f_fstypename, "procfs") != 0)
1371 		return (0);
1372 	return (1);
1373 }
1374 
1375 static void
1376 usage(void)
1377 {
1378 #define	SINGLE_OPTS	"[-aCcde" OPT_LAZY_f "HhjlmrSTuvwXxZ]"
1379 
1380 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
1381 	    "usage: ps " SINGLE_OPTS " [-O fmt | -o fmt] [-G gid[,gid...]]",
1382 	    "          [-M core] [-N system]",
1383 	    "          [-p pid[,pid...]] [-t tty[,tty...]] [-U user[,user...]]",
1384 	    "       ps [-L]");
1385 	exit(1);
1386 }
1387