xref: /freebsd/bin/pkill/pkill.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*	$NetBSD: pkill.c,v 1.16 2005/10/10 22:13:20 kleink Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c) 2002 The NetBSD Foundation, Inc.
7  * Copyright (c) 2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
8  * All rights reserved.
9  *
10  * This code is derived from software contributed to The NetBSD Foundation
11  * by Andrew Doran.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #include <sys/types.h>
37 #include <sys/param.h>
38 #include <sys/sysctl.h>
39 #include <sys/proc.h>
40 #include <sys/queue.h>
41 #include <sys/stat.h>
42 #include <sys/time.h>
43 #include <sys/user.h>
44 
45 #include <assert.h>
46 #include <stdbool.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <limits.h>
50 #include <paths.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <signal.h>
54 #include <regex.h>
55 #include <ctype.h>
56 #include <fcntl.h>
57 #include <kvm.h>
58 #include <err.h>
59 #include <pwd.h>
60 #include <grp.h>
61 #include <errno.h>
62 #include <locale.h>
63 #include <jail.h>
64 
65 #define	STATUS_MATCH	0
66 #define	STATUS_NOMATCH	1
67 #define	STATUS_BADUSAGE	2
68 #define	STATUS_ERROR	3
69 
70 #define	MIN_PID	5
71 #define	MAX_PID	99999
72 
73 /* Ignore system-processes (if '-S' flag is not specified) and myself. */
74 #define	PSKIP(kp)	((kp)->ki_pid == mypid ||			\
75 			 (!kthreads && ((kp)->ki_flag & P_KPROC) != 0))
76 
77 enum listtype {
78 	LT_GENERIC,
79 	LT_USER,
80 	LT_GROUP,
81 	LT_TTY,
82 	LT_PGRP,
83 	LT_JAIL,
84 	LT_SID,
85 	LT_CLASS
86 };
87 
88 struct list {
89 	SLIST_ENTRY(list) li_chain;
90 	long	li_number;
91 	char	*li_name;
92 };
93 
94 SLIST_HEAD(listhead, list);
95 
96 static struct kinfo_proc *plist;
97 static char	*selected;
98 static const char *delim = "\n";
99 static int	nproc;
100 static int	pgrep;
101 static int	signum = SIGTERM;
102 static int	newest;
103 static int	oldest;
104 static int	interactive;
105 static int	inverse;
106 static int	longfmt;
107 static int	matchargs;
108 static int	fullmatch;
109 static int	kthreads;
110 static int	cflags = REG_EXTENDED;
111 static int	quiet;
112 static kvm_t	*kd;
113 static pid_t	mypid;
114 
115 static struct listhead euidlist = SLIST_HEAD_INITIALIZER(euidlist);
116 static struct listhead ruidlist = SLIST_HEAD_INITIALIZER(ruidlist);
117 static struct listhead rgidlist = SLIST_HEAD_INITIALIZER(rgidlist);
118 static struct listhead pgrplist = SLIST_HEAD_INITIALIZER(pgrplist);
119 static struct listhead ppidlist = SLIST_HEAD_INITIALIZER(ppidlist);
120 static struct listhead tdevlist = SLIST_HEAD_INITIALIZER(tdevlist);
121 static struct listhead sidlist = SLIST_HEAD_INITIALIZER(sidlist);
122 static struct listhead jidlist = SLIST_HEAD_INITIALIZER(jidlist);
123 static struct listhead classlist = SLIST_HEAD_INITIALIZER(classlist);
124 
125 static void	usage(void) __attribute__((__noreturn__));
126 static int	killact(const struct kinfo_proc *);
127 static int	grepact(const struct kinfo_proc *);
128 static void	makelist(struct listhead *, enum listtype, char *);
129 static int	takepid(const char *, int);
130 
131 int
132 main(int argc, char **argv)
133 {
134 	char *buf, *mstr, **pargv, *p, *q, *pidfile;
135 	const char *execf, *coref;
136 	size_t bufsz;
137 	int ancestors, debug_opt, did_action;
138 	int i, ch, bestidx, rv, criteria, pidfromfile, pidfilelock;
139 	size_t jsz;
140 	int (*action)(const struct kinfo_proc *);
141 	struct kinfo_proc *kp;
142 	struct list *li;
143 	struct timeval best_tval;
144 	regex_t reg;
145 	regmatch_t regmatch;
146 	pid_t pid;
147 
148 	setlocale(LC_ALL, "");
149 
150 	if (strcmp(getprogname(), "pgrep") == 0) {
151 		action = grepact;
152 		pgrep = 1;
153 	} else {
154 		action = killact;
155 		p = argv[1];
156 
157 		if (argc > 1 && p[0] == '-') {
158 			p++;
159 			i = (int)strtol(p, &q, 10);
160 			if (*q == '\0') {
161 				signum = i;
162 				argv++;
163 				argc--;
164 			} else {
165 				if (strncasecmp(p, "SIG", 3) == 0)
166 					p += 3;
167 				for (i = 1; i < NSIG; i++)
168 					if (strcasecmp(sys_signame[i], p) == 0)
169 						break;
170 				if (i != NSIG) {
171 					signum = i;
172 					argv++;
173 					argc--;
174 				}
175 			}
176 		}
177 	}
178 
179 	buf = NULL;
180 	ancestors = 0;
181 	criteria = 0;
182 	debug_opt = 0;
183 	pidfile = NULL;
184 	pidfilelock = 0;
185 	quiet = 0;
186 	execf = NULL;
187 	coref = _PATH_DEVNULL;
188 
189 	while ((ch = getopt(argc, argv, "DF:G:ILM:N:P:SU:ac:d:fg:ij:lnoqs:t:u:vx")) != -1)
190 		switch (ch) {
191 		case 'D':
192 			debug_opt++;
193 			break;
194 		case 'F':
195 			pidfile = optarg;
196 			criteria = 1;
197 			break;
198 		case 'G':
199 			makelist(&rgidlist, LT_GROUP, optarg);
200 			criteria = 1;
201 			break;
202 		case 'I':
203 			if (pgrep)
204 				usage();
205 			interactive = 1;
206 			break;
207 		case 'L':
208 			pidfilelock = 1;
209 			break;
210 		case 'M':
211 			coref = optarg;
212 			break;
213 		case 'N':
214 			execf = optarg;
215 			break;
216 		case 'P':
217 			makelist(&ppidlist, LT_GENERIC, optarg);
218 			criteria = 1;
219 			break;
220 		case 'S':
221 			if (!pgrep)
222 				usage();
223 			kthreads = 1;
224 			break;
225 		case 'U':
226 			makelist(&ruidlist, LT_USER, optarg);
227 			criteria = 1;
228 			break;
229 		case 'a':
230 			ancestors++;
231 			break;
232 		case 'c':
233 			makelist(&classlist, LT_CLASS, optarg);
234 			criteria = 1;
235 			break;
236 		case 'd':
237 			if (!pgrep)
238 				usage();
239 			delim = optarg;
240 			break;
241 		case 'f':
242 			matchargs = 1;
243 			break;
244 		case 'g':
245 			makelist(&pgrplist, LT_PGRP, optarg);
246 			criteria = 1;
247 			break;
248 		case 'i':
249 			cflags |= REG_ICASE;
250 			break;
251 		case 'j':
252 			makelist(&jidlist, LT_JAIL, optarg);
253 			criteria = 1;
254 			break;
255 		case 'l':
256 			longfmt = 1;
257 			break;
258 		case 'n':
259 			newest = 1;
260 			criteria = 1;
261 			break;
262 		case 'o':
263 			oldest = 1;
264 			criteria = 1;
265 			break;
266 		case 'q':
267 			if (!pgrep)
268 				usage();
269 			quiet = 1;
270 			break;
271 		case 's':
272 			makelist(&sidlist, LT_SID, optarg);
273 			criteria = 1;
274 			break;
275 		case 't':
276 			makelist(&tdevlist, LT_TTY, optarg);
277 			criteria = 1;
278 			break;
279 		case 'u':
280 			makelist(&euidlist, LT_USER, optarg);
281 			criteria = 1;
282 			break;
283 		case 'v':
284 			inverse = 1;
285 			break;
286 		case 'x':
287 			fullmatch = 1;
288 			break;
289 		default:
290 			usage();
291 			/* NOTREACHED */
292 		}
293 
294 	argc -= optind;
295 	argv += optind;
296 	if (argc != 0)
297 		criteria = 1;
298 	if (!criteria)
299 		usage();
300 	if (newest && oldest)
301 		errx(STATUS_ERROR, "Options -n and -o are mutually exclusive");
302 	if (pidfile != NULL)
303 		pidfromfile = takepid(pidfile, pidfilelock);
304 	else {
305 		if (pidfilelock) {
306 			errx(STATUS_ERROR,
307 			    "Option -L doesn't make sense without -F");
308 		}
309 		pidfromfile = -1;
310 	}
311 
312 	mypid = getpid();
313 
314 	/*
315 	 * If we're not matching args, we only need a buffer large enough to
316 	 * hold some relatively short error strings.  Otherwise, we have to
317 	 * assume we'll need up to ARG_MAX bytes for arguments.
318 	 */
319 	bufsz = _POSIX2_LINE_MAX;
320 	if (matchargs) {
321 		long arg_max;
322 
323 		arg_max = sysconf(_SC_ARG_MAX);
324 		if (arg_max == -1)
325 			arg_max = ARG_MAX;
326 
327 		/*
328 		 * The absolute worst case scenario is ARG_MAX single-byte
329 		 * arguments which we'll then separate with spaces and NUL
330 		 * terminate.
331 		 */
332 		bufsz = (arg_max * 2) + 1;
333 	}
334 
335 	buf = malloc(bufsz);
336 	if (buf == NULL)
337 		err(STATUS_ERROR, "malloc");
338 
339 	/*
340 	 * Retrieve the list of running processes from the kernel.
341 	 */
342 	kd = kvm_openfiles(execf, coref, NULL, O_RDONLY, buf);
343 	if (kd == NULL)
344 		errx(STATUS_ERROR, "Cannot open kernel files (%s)", buf);
345 
346 	/*
347 	 * Use KERN_PROC_PROC instead of KERN_PROC_ALL, since we
348 	 * just want processes and not individual kernel threads.
349 	 */
350 	if (pidfromfile >= 0)
351 		plist = kvm_getprocs(kd, KERN_PROC_PID, pidfromfile, &nproc);
352 	else
353 		plist = kvm_getprocs(kd, KERN_PROC_PROC, 0, &nproc);
354 	if (plist == NULL) {
355 		errx(STATUS_ERROR, "Cannot get process list (%s)",
356 		    kvm_geterr(kd));
357 	}
358 
359 	/*
360 	 * Allocate memory which will be used to keep track of the
361 	 * selection.
362 	 */
363 	if ((selected = malloc(nproc)) == NULL) {
364 		err(STATUS_ERROR, "Cannot allocate memory for %d processes",
365 		    nproc);
366 	}
367 	memset(selected, 0, nproc);
368 
369 	/*
370 	 * Refine the selection.
371 	 */
372 	for (; *argv != NULL; argv++) {
373 		if ((rv = regcomp(&reg, *argv, cflags)) != 0) {
374 			regerror(rv, &reg, buf, bufsz);
375 			errx(STATUS_BADUSAGE,
376 			    "Cannot compile regular expression `%s' (%s)",
377 			    *argv, buf);
378 		}
379 
380 		for (i = 0, kp = plist; i < nproc; i++, kp++) {
381 			if (PSKIP(kp)) {
382 				if (debug_opt > 0)
383 				    fprintf(stderr, "* Skipped %5d %3d %s\n",
384 					kp->ki_pid, kp->ki_uid, kp->ki_comm);
385 				continue;
386 			}
387 
388 			if (matchargs &&
389 			    (pargv = kvm_getargv(kd, kp, 0)) != NULL) {
390 				jsz = 0;
391 				while (jsz < bufsz && *pargv != NULL) {
392 					jsz += snprintf(buf + jsz,
393 					    bufsz - jsz,
394 					    pargv[1] != NULL ? "%s " : "%s",
395 					    pargv[0]);
396 					pargv++;
397 				}
398 				mstr = buf;
399 			} else
400 				mstr = kp->ki_comm;
401 
402 			rv = regexec(&reg, mstr, 1, &regmatch, 0);
403 			if (rv == 0) {
404 				if (fullmatch) {
405 					if (regmatch.rm_so == 0 &&
406 					    regmatch.rm_eo ==
407 					    (off_t)strlen(mstr))
408 						selected[i] = 1;
409 				} else
410 					selected[i] = 1;
411 			} else if (rv != REG_NOMATCH) {
412 				regerror(rv, &reg, buf, bufsz);
413 				errx(STATUS_ERROR,
414 				    "Regular expression evaluation error (%s)",
415 				    buf);
416 			}
417 			if (debug_opt > 1) {
418 				const char *rv_res = "NoMatch";
419 				if (selected[i])
420 					rv_res = "Matched";
421 				fprintf(stderr, "* %s %5d %3d %s\n", rv_res,
422 				    kp->ki_pid, kp->ki_uid, mstr);
423 			}
424 		}
425 
426 		regfree(&reg);
427 	}
428 
429 	for (i = 0, kp = plist; i < nproc; i++, kp++) {
430 		if (PSKIP(kp))
431 			continue;
432 
433 		if (pidfromfile >= 0 && kp->ki_pid != pidfromfile) {
434 			selected[i] = 0;
435 			continue;
436 		}
437 
438 		SLIST_FOREACH(li, &ruidlist, li_chain)
439 			if (kp->ki_ruid == (uid_t)li->li_number)
440 				break;
441 		if (SLIST_FIRST(&ruidlist) != NULL && li == NULL) {
442 			selected[i] = 0;
443 			continue;
444 		}
445 
446 		SLIST_FOREACH(li, &rgidlist, li_chain)
447 			if (kp->ki_rgid == (gid_t)li->li_number)
448 				break;
449 		if (SLIST_FIRST(&rgidlist) != NULL && li == NULL) {
450 			selected[i] = 0;
451 			continue;
452 		}
453 
454 		SLIST_FOREACH(li, &euidlist, li_chain)
455 			if (kp->ki_uid == (uid_t)li->li_number)
456 				break;
457 		if (SLIST_FIRST(&euidlist) != NULL && li == NULL) {
458 			selected[i] = 0;
459 			continue;
460 		}
461 
462 		SLIST_FOREACH(li, &ppidlist, li_chain)
463 			if (kp->ki_ppid == (pid_t)li->li_number)
464 				break;
465 		if (SLIST_FIRST(&ppidlist) != NULL && li == NULL) {
466 			selected[i] = 0;
467 			continue;
468 		}
469 
470 		SLIST_FOREACH(li, &pgrplist, li_chain)
471 			if (kp->ki_pgid == (pid_t)li->li_number)
472 				break;
473 		if (SLIST_FIRST(&pgrplist) != NULL && li == NULL) {
474 			selected[i] = 0;
475 			continue;
476 		}
477 
478 		SLIST_FOREACH(li, &tdevlist, li_chain) {
479 			if (li->li_number == -1 &&
480 			    (kp->ki_flag & P_CONTROLT) == 0)
481 				break;
482 			if (kp->ki_tdev == (dev_t)li->li_number)
483 				break;
484 		}
485 		if (SLIST_FIRST(&tdevlist) != NULL && li == NULL) {
486 			selected[i] = 0;
487 			continue;
488 		}
489 
490 		SLIST_FOREACH(li, &sidlist, li_chain)
491 			if (kp->ki_sid == (pid_t)li->li_number)
492 				break;
493 		if (SLIST_FIRST(&sidlist) != NULL && li == NULL) {
494 			selected[i] = 0;
495 			continue;
496 		}
497 
498 		SLIST_FOREACH(li, &jidlist, li_chain) {
499 			/* A particular jail ID, including 0 (not in jail) */
500 			if (kp->ki_jid == (int)li->li_number)
501 				break;
502 			/* Any jail */
503 			if (kp->ki_jid > 0 && li->li_number == -1)
504 				break;
505 		}
506 		if (SLIST_FIRST(&jidlist) != NULL && li == NULL) {
507 			selected[i] = 0;
508 			continue;
509 		}
510 
511 		SLIST_FOREACH(li, &classlist, li_chain) {
512 			/*
513 			 * We skip P_SYSTEM processes to match ps(1) output.
514 			 */
515 			if ((kp->ki_flag & P_SYSTEM) == 0 &&
516 			    strcmp(kp->ki_loginclass, li->li_name) == 0)
517 				break;
518 		}
519 		if (SLIST_FIRST(&classlist) != NULL && li == NULL) {
520 			selected[i] = 0;
521 			continue;
522 		}
523 
524 		if (argc == 0)
525 			selected[i] = 1;
526 	}
527 
528 	if (!ancestors) {
529 		pid = mypid;
530 		while (pid) {
531 			for (i = 0, kp = plist; i < nproc; i++, kp++) {
532 				if (PSKIP(kp))
533 					continue;
534 				if (kp->ki_pid == pid) {
535 					selected[i] = 0;
536 					pid = kp->ki_ppid;
537 					break;
538 				}
539 			}
540 			if (i == nproc) {
541 				if (pid == mypid)
542 					pid = getppid();
543 				else
544 					break;	/* Maybe we're in a jail ? */
545 			}
546 		}
547 	}
548 
549 	if (newest || oldest) {
550 		best_tval.tv_sec = 0;
551 		best_tval.tv_usec = 0;
552 		bestidx = -1;
553 
554 		for (i = 0, kp = plist; i < nproc; i++, kp++) {
555 			if (!selected[i])
556 				continue;
557 			if (bestidx == -1) {
558 				/* The first entry of the list which matched. */
559 				;
560 			} else if (timercmp(&kp->ki_start, &best_tval, >)) {
561 				/* This entry is newer than previous "best". */
562 				if (oldest)	/* but we want the oldest */
563 					continue;
564 			} else {
565 				/* This entry is older than previous "best". */
566 				if (newest)	/* but we want the newest */
567 					continue;
568 			}
569 			/* This entry is better than previous "best" entry. */
570 			best_tval.tv_sec = kp->ki_start.tv_sec;
571 			best_tval.tv_usec = kp->ki_start.tv_usec;
572 			bestidx = i;
573 		}
574 
575 		memset(selected, 0, nproc);
576 		if (bestidx != -1)
577 			selected[bestidx] = 1;
578 	}
579 
580 	/*
581 	 * Take the appropriate action for each matched process, if any.
582 	 */
583 	did_action = 0;
584 	for (i = 0, rv = 0, kp = plist; i < nproc; i++, kp++) {
585 		if (PSKIP(kp))
586 			continue;
587 		if (selected[i]) {
588 			if (longfmt && !pgrep) {
589 				did_action = 1;
590 				printf("kill -%d %d\n", signum, kp->ki_pid);
591 			}
592 			if (inverse)
593 				continue;
594 		} else if (!inverse)
595 			continue;
596 		rv |= (*action)(kp);
597 	}
598 	if (rv && pgrep && !quiet)
599 		putchar('\n');
600 	if (!did_action && !pgrep && longfmt)
601 		fprintf(stderr,
602 		    "No matching processes belonging to you were found\n");
603 
604 	free(buf);
605 	exit(rv ? STATUS_MATCH : STATUS_NOMATCH);
606 }
607 
608 static void
609 usage(void)
610 {
611 	const char *ustr;
612 
613 	if (pgrep)
614 		ustr = "[-LSfilnoqvx] [-d delim]";
615 	else
616 		ustr = "[-signal] [-ILfilnovx]";
617 
618 	fprintf(stderr,
619 		"usage: %s %s [-F pidfile] [-G gid] [-M core] [-N system]\n"
620 		"             [-P ppid] [-U uid] [-c class] [-g pgrp] [-j jail]\n"
621 		"             [-s sid] [-t tty] [-u euid] pattern ...\n",
622 		getprogname(), ustr);
623 
624 	exit(STATUS_BADUSAGE);
625 }
626 
627 static void
628 show_process(const struct kinfo_proc *kp)
629 {
630 	char **argv;
631 
632 	if (quiet) {
633 		assert(pgrep);
634 		return;
635 	}
636 	if ((longfmt || !pgrep) && matchargs &&
637 	    (argv = kvm_getargv(kd, kp, 0)) != NULL) {
638 		printf("%d ", (int)kp->ki_pid);
639 		for (; *argv != NULL; argv++) {
640 			printf("%s", *argv);
641 			if (argv[1] != NULL)
642 				putchar(' ');
643 		}
644 	} else if (longfmt || !pgrep)
645 		printf("%d %s", (int)kp->ki_pid, kp->ki_comm);
646 	else
647 		printf("%d", (int)kp->ki_pid);
648 }
649 
650 static int
651 killact(const struct kinfo_proc *kp)
652 {
653 	int ch, first;
654 
655 	if (interactive) {
656 		/*
657 		 * Be careful, ask before killing.
658 		 */
659 		printf("kill ");
660 		show_process(kp);
661 		printf("? ");
662 		fflush(stdout);
663 		first = ch = getchar();
664 		while (ch != '\n' && ch != EOF)
665 			ch = getchar();
666 		if (first != 'y' && first != 'Y')
667 			return (1);
668 	}
669 	if (kill(kp->ki_pid, signum) == -1) {
670 		/*
671 		 * Check for ESRCH, which indicates that the process
672 		 * disappeared between us matching it and us
673 		 * signalling it; don't issue a warning about it.
674 		 */
675 		if (errno != ESRCH)
676 			warn("signalling pid %d", (int)kp->ki_pid);
677 		/*
678 		 * Return 0 to indicate that the process should not be
679 		 * considered a match, since we didn't actually get to
680 		 * signal it.
681 		 */
682 		return (0);
683 	}
684 	return (1);
685 }
686 
687 static int
688 grepact(const struct kinfo_proc *kp)
689 {
690 	static bool first = true;
691 
692 	if (!quiet && !first)
693 		printf("%s", delim);
694 	show_process(kp);
695 	first = false;
696 	return (1);
697 }
698 
699 static void
700 makelist(struct listhead *head, enum listtype type, char *src)
701 {
702 	struct list *li;
703 	struct passwd *pw;
704 	struct group *gr;
705 	struct stat st;
706 	const char *cp;
707 	char *sp, *ep, buf[MAXPATHLEN];
708 	int empty;
709 
710 	empty = 1;
711 
712 	while ((sp = strsep(&src, ",")) != NULL) {
713 		if (*sp == '\0')
714 			usage();
715 
716 		if ((li = malloc(sizeof(*li))) == NULL) {
717 			err(STATUS_ERROR, "Cannot allocate %zu bytes",
718 			    sizeof(*li));
719 		}
720 
721 		SLIST_INSERT_HEAD(head, li, li_chain);
722 		empty = 0;
723 
724 		if (type != LT_CLASS)
725 			li->li_number = (uid_t)strtol(sp, &ep, 0);
726 
727 		if (type != LT_CLASS && *ep == '\0') {
728 			switch (type) {
729 			case LT_PGRP:
730 				if (li->li_number == 0)
731 					li->li_number = getpgrp();
732 				break;
733 			case LT_SID:
734 				if (li->li_number == 0)
735 					li->li_number = getsid(mypid);
736 				break;
737 			case LT_JAIL:
738 				if (li->li_number < 0)
739 					errx(STATUS_BADUSAGE,
740 					     "Negative jail ID `%s'", sp);
741 				/* For compatibility with old -j */
742 				if (li->li_number == 0)
743 					li->li_number = -1;	/* any jail */
744 				break;
745 			case LT_TTY:
746 				if (li->li_number < 0)
747 					errx(STATUS_BADUSAGE,
748 					     "Negative /dev/pts tty `%s'", sp);
749 				snprintf(buf, sizeof(buf), _PATH_DEV "pts/%s",
750 				    sp);
751 				if (stat(buf, &st) != -1)
752 					goto foundtty;
753 				if (errno == ENOENT)
754 					errx(STATUS_BADUSAGE, "No such tty: `"
755 					    _PATH_DEV "pts/%s'", sp);
756 				err(STATUS_ERROR, "Cannot access `"
757 				    _PATH_DEV "pts/%s'", sp);
758 				break;
759 			default:
760 				break;
761 			}
762 			continue;
763 		}
764 
765 		switch (type) {
766 		case LT_USER:
767 			if ((pw = getpwnam(sp)) == NULL)
768 				errx(STATUS_BADUSAGE, "Unknown user `%s'", sp);
769 			li->li_number = pw->pw_uid;
770 			break;
771 		case LT_GROUP:
772 			if ((gr = getgrnam(sp)) == NULL)
773 				errx(STATUS_BADUSAGE, "Unknown group `%s'", sp);
774 			li->li_number = gr->gr_gid;
775 			break;
776 		case LT_TTY:
777 			if (strcmp(sp, "-") == 0) {
778 				li->li_number = -1;
779 				break;
780 			} else if (strcmp(sp, "co") == 0) {
781 				cp = "console";
782 			} else {
783 				cp = sp;
784 			}
785 
786 			snprintf(buf, sizeof(buf), _PATH_DEV "%s", cp);
787 			if (stat(buf, &st) != -1)
788 				goto foundtty;
789 
790 			snprintf(buf, sizeof(buf), _PATH_DEV "tty%s", cp);
791 			if (stat(buf, &st) != -1)
792 				goto foundtty;
793 
794 			if (errno == ENOENT)
795 				errx(STATUS_BADUSAGE, "No such tty: `%s'", sp);
796 			err(STATUS_ERROR, "Cannot access `%s'", sp);
797 
798 foundtty:		if ((st.st_mode & S_IFCHR) == 0)
799 				errx(STATUS_BADUSAGE, "Not a tty: `%s'", sp);
800 
801 			li->li_number = st.st_rdev;
802 			break;
803 		case LT_JAIL: {
804 			int jid;
805 
806 			if (strcmp(sp, "none") == 0)
807 				li->li_number = 0;
808 			else if (strcmp(sp, "any") == 0)
809 				li->li_number = -1;
810 			else if ((jid = jail_getid(sp)) != -1)
811 				li->li_number = jid;
812 			else if (*ep != '\0')
813 				errx(STATUS_BADUSAGE,
814 				     "Invalid jail ID or name `%s'", sp);
815 			break;
816 		}
817 		case LT_CLASS:
818 			li->li_number = -1;
819 			li->li_name = strdup(sp);
820 			if (li->li_name == NULL)
821 				err(STATUS_ERROR, "Cannot allocate memory");
822 			break;
823 		default:
824 			usage();
825 		}
826 	}
827 
828 	if (empty)
829 		usage();
830 }
831 
832 static int
833 takepid(const char *pidfile, int pidfilelock)
834 {
835 	char *endp, line[BUFSIZ];
836 	FILE *fh;
837 	long rval;
838 
839 	fh = fopen(pidfile, "r");
840 	if (fh == NULL)
841 		err(STATUS_ERROR, "Cannot open pidfile `%s'", pidfile);
842 
843 	if (pidfilelock) {
844 		/*
845 		 * If we can lock pidfile, this means that daemon is not
846 		 * running, so would be better not to kill some random process.
847 		 */
848 		if (flock(fileno(fh), LOCK_EX | LOCK_NB) == 0) {
849 			(void)fclose(fh);
850 			errx(STATUS_ERROR, "File '%s' can be locked", pidfile);
851 		} else {
852 			if (errno != EWOULDBLOCK) {
853 				errx(STATUS_ERROR,
854 				    "Error while locking file '%s'", pidfile);
855 			}
856 		}
857 	}
858 
859 	if (fgets(line, sizeof(line), fh) == NULL) {
860 		if (feof(fh)) {
861 			(void)fclose(fh);
862 			errx(STATUS_ERROR, "Pidfile `%s' is empty", pidfile);
863 		}
864 		(void)fclose(fh);
865 		err(STATUS_ERROR, "Cannot read from pid file `%s'", pidfile);
866 	}
867 	(void)fclose(fh);
868 
869 	rval = strtol(line, &endp, 10);
870 	if (*endp != '\0' && !isspace((unsigned char)*endp))
871 		errx(STATUS_ERROR, "Invalid pid in file `%s'", pidfile);
872 	else if (rval < MIN_PID || rval > MAX_PID)
873 		errx(STATUS_ERROR, "Invalid pid in file `%s'", pidfile);
874 	return (rval);
875 }
876