xref: /netbsd-src/bin/kill/kill.c (revision 32cc3b02487f28a4afee3a936163698c954d5a47)
1 /* $NetBSD: kill.c,v 1.33 2022/05/16 10:53:14 kre Exp $ */
2 
3 /*
4  * Copyright (c) 1988, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if !defined(lint) && !defined(SHELL)
34 __COPYRIGHT("@(#) Copyright (c) 1988, 1993, 1994\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)kill.c	8.4 (Berkeley) 4/28/95";
41 #else
42 __RCSID("$NetBSD: kill.c,v 1.33 2022/05/16 10:53:14 kre Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <ctype.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <signal.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <limits.h>
53 #include <inttypes.h>
54 #include <string.h>
55 #include <termios.h>
56 #include <unistd.h>
57 #include <locale.h>
58 #include <sys/ioctl.h>
59 
60 #ifdef SHELL            /* sh (aka ash) builtin */
61 int killcmd(int, char *argv[]);
62 #define main killcmd
63 #include "../../bin/sh/bltin/bltin.h"
64 #endif /* SHELL */
65 
66 __dead static void nosig(const char *);
67 void printsignals(FILE *, int);
68 static int signum(const char *);
69 static int processnum(const char *, pid_t *);
70 __dead static void usage(void);
71 
72 int
main(int argc,char * argv[])73 main(int argc, char *argv[])
74 {
75 	int errors;
76 	int numsig;
77 	pid_t pid;
78 	const char *sn;
79 
80 	setprogname(argv[0]);
81 	setlocale(LC_ALL, "");
82 	if (argc < 2)
83 		usage();
84 
85 	numsig = SIGTERM;
86 
87 	argc--, argv++;
88 
89 	/*
90 	 * Process exactly 1 option, if there is one.
91 	 */
92 	if (argv[0][0] == '-') {
93 		switch (argv[0][1]) {
94 		case 'l':
95 			if (argv[0][2] != '\0')
96 				sn = argv[0] + 2;
97 			else {
98 				argc--; argv++;
99 				sn = argv[0];
100 			}
101 			if (argc > 1)
102 				usage();
103 			if (argc == 1) {
104 				if (isdigit((unsigned char)*sn) == 0)
105 					usage();
106 				numsig = signum(sn);
107 				if (numsig >= 128)
108 					numsig -= 128;
109 				if (numsig == 0 || signalnext(numsig) == -1)
110 					nosig(sn);
111 				sn = signalname(numsig);
112 				if (sn == NULL)
113 					errx(EXIT_FAILURE,
114 					   "unknown signal number: %d", numsig);
115 				printf("%s\n", sn);
116 				exit(0);
117 			}
118 			printsignals(stdout, 0);
119 			exit(0);
120 
121 		case 's':
122 			if (argv[0][2] != '\0')
123 				sn = argv[0] + 2;
124 			else {
125 				argc--, argv++;
126 				if (argc < 1) {
127 					warnx(
128 					    "option requires an argument -- s");
129 					usage();
130 				}
131 				sn = argv[0];
132 			}
133 			if (strcmp(sn, "0") == 0)
134 				numsig = 0;
135 			else if ((numsig = signalnumber(sn)) == 0) {
136 				if (sn != argv[0])
137 					goto trysignal;
138 				nosig(sn);
139 			}
140 			argc--, argv++;
141 			break;
142 
143 		case '-':
144 			if (argv[0][2] == '\0') {
145 				/* process this one again later */
146 				break;
147 			}
148 			/* FALL THROUGH */
149 		case '\0':
150 			usage();
151 			break;
152 
153 		default:
154  trysignal:
155 			sn = *argv + 1;
156 			if (((numsig = signalnumber(sn)) == 0)) {
157 				if (isdigit((unsigned char)*sn))
158 					numsig = signum(sn);
159 				else
160 					nosig(sn);
161 			}
162 
163 			if (numsig != 0 && signalnext(numsig) == -1)
164 				nosig(sn);
165 			argc--, argv++;
166 			break;
167 		}
168 	}
169 
170 	/* deal with the optional '--' end of options option */
171 	if (argc > 0 && strcmp(*argv, "--") == 0)
172 		argc--, argv++;
173 
174 	if (argc == 0)
175 		usage();
176 
177 	for (errors = 0; argc; argc--, argv++) {
178 #ifdef SHELL
179 		extern int getjobpgrp(const char *);
180 
181 		if (*argv[0] == '%') {
182 			pid = getjobpgrp(*argv);
183 			if (pid == 0) {
184 				warnx("bad job id: %s", *argv);
185 				errors = 1;
186 				continue;
187 			}
188 		} else
189 #endif
190 			if (processnum(*argv, &pid) != 0) {
191 				errors = 1;
192 				continue;
193 			}
194 
195 		if (kill(pid, numsig) == -1) {
196 			warn("%s %s", pid < -1 ? "pgrp" : "pid", *argv);
197 			errors = 1;
198 		}
199 #ifdef SHELL
200 		/*
201 		 * Wakeup the process if it was suspended, so it can
202 		 * exit without an explicit 'fg'.
203 		 *	(kernel handles this for SIGKILL)
204 		 */
205 		if (numsig == SIGTERM || numsig == SIGHUP)
206 			kill(pid, SIGCONT);
207 #endif
208 	}
209 
210 	exit(errors);
211 	/* NOTREACHED */
212 }
213 
214 static int
signum(const char * sn)215 signum(const char *sn)
216 {
217 	intmax_t n;
218 	char *ep;
219 
220 	n = strtoimax(sn, &ep, 10);
221 
222 	/* check for correctly parsed number */
223 	if (*ep || n <= INT_MIN || n >= INT_MAX )
224 		errx(EXIT_FAILURE, "bad signal number: %s", sn);
225 		/* NOTREACHED */
226 
227 	return (int)n;
228 }
229 
230 static int
processnum(const char * s,pid_t * pid)231 processnum(const char *s, pid_t *pid)
232 {
233 	intmax_t n;
234 	char *ep;
235 
236 	errno = 0;
237 	n = strtoimax(s, &ep, 10);
238 
239 	/* check for correctly parsed number */
240 	if (ep == s || *ep || n == INTMAX_MIN || n == INTMAX_MAX ||
241 	    (pid_t)n != n || errno != 0) {
242 		warnx("bad process%s id: '%s'", (n < 0 ? " group" : ""), s);
243 		return -1;
244 	}
245 
246 	*pid = (pid_t)n;
247 	return 0;
248 }
249 
250 static void
nosig(const char * name)251 nosig(const char *name)
252 {
253 
254 	warnx("unknown signal %s; valid signals:", name);
255 	printsignals(stderr, 0);
256 	exit(1);
257 	/* NOTREACHED */
258 }
259 
260 #ifndef SHELL
261 /*
262  * Print the names of all the signals (neatly) to fp
263  * "len" gives the number of chars already printed to
264  * the current output line (in kill.c, always 0)
265  */
266 void
printsignals(FILE * fp,int len)267 printsignals(FILE *fp, int len)
268 {
269 	int sig;
270 	int nl, pad;
271 	const char *name;
272 	int termwidth = 80;
273 	int posix;
274 
275 	posix = getenv("POSIXLY_CORRECT") != 0;
276 	if ((name = getenv("COLUMNS")) != 0)
277 		termwidth = atoi(name);
278 	else if (isatty(fileno(fp))) {
279 		struct winsize win;
280 
281 		if (ioctl(fileno(fp), TIOCGWINSZ, &win) == 0 && win.ws_col > 0)
282 			termwidth = win.ws_col;
283 	}
284 
285 	pad = (len | 7) + 1 - len;
286 	if (posix && pad)
287 		pad = 1;
288 
289 	for (sig = 0; (sig = signalnext(sig)) != 0; ) {
290 		name = signalname(sig);
291 		if (name == NULL)
292 			continue;
293 
294 		nl = strlen(name);
295 
296 		if (len > 0 && nl + len + pad >= termwidth) {
297 			fprintf(fp, "\n");
298 			len = 0;
299 			pad = 0;
300 		} else if (pad > 0 && len != 0)
301 			fprintf(fp, "%*s", pad, "");
302 		else
303 			pad = 0;
304 
305 		len += nl + pad;
306 		pad = (nl | 7) + 1 - nl;
307 		if (posix && pad)
308 			pad = 1;
309 
310 		fprintf(fp, "%s", name);
311 	}
312 	if (len != 0)
313 		fprintf(fp, "\n");
314 }
315 #endif
316 
317 static void
usage(void)318 usage(void)
319 {
320 	const char *pn = getprogname();
321 
322 	fprintf(stderr, "usage: %s [-s signal_name] pid ...\n"
323 			"       %s -l [exit_status]\n"
324 			"       %s -signal_name pid ...\n"
325 			"       %s -signal_number pid ...\n",
326 	    pn, pn, pn, pn);
327 	exit(1);
328 	/* NOTREACHED */
329 }
330