xref: /netbsd-src/bin/kill/kill.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* $NetBSD: kill.c,v 1.28 2017/06/26 22:09:16 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 1.28 2017/06/26 22:09:16 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 static void printsignals(FILE *);
68 static int signum(const char *);
69 static pid_t processnum(const char *);
70 __dead static void usage(void);
71 
72 int
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);
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 		if (*argv[0] == '%') {
181 			pid = getjobpgrp(*argv);
182 			if (pid == 0) {
183 				warnx("illegal job id: %s", *argv);
184 				errors = 1;
185 				continue;
186 			}
187 		} else
188 #endif
189 			if ((pid = processnum(*argv)) == (pid_t)-1) {
190 				errors = 1;
191 				continue;
192 			}
193 
194 		if (kill(pid, numsig) == -1) {
195 			warn("%s", *argv);
196 			errors = 1;
197 		}
198 #ifdef SHELL
199 		/*
200 		 * Wakeup the process if it was suspended, so it can
201 		 * exit without an explicit 'fg'.
202 		 *	(kernel handles this for SIGKILL)
203 		 */
204 		if (numsig == SIGTERM || numsig == SIGHUP)
205 			kill(pid, SIGCONT);
206 #endif
207 	}
208 
209 	exit(errors);
210 	/* NOTREACHED */
211 }
212 
213 static int
214 signum(const char *sn)
215 {
216 	intmax_t n;
217 	char *ep;
218 
219 	n = strtoimax(sn, &ep, 10);
220 
221 	/* check for correctly parsed number */
222 	if (*ep || n <= INT_MIN || n >= INT_MAX )
223 		errx(EXIT_FAILURE, "illegal signal number: %s", sn);
224 		/* NOTREACHED */
225 
226 	return (int)n;
227 }
228 
229 static pid_t
230 processnum(const char *s)
231 {
232 	intmax_t n;
233 	char *ep;
234 
235 	n = strtoimax(s, &ep, 10);
236 
237 	/* check for correctly parsed number */
238 	if (*ep || n == INTMAX_MIN || n == INTMAX_MAX || (pid_t)n != n ||
239 	    n == -1) {
240 		warnx("illegal process%s id: %s", (n < 0 ? " group" : ""), s);
241 		n = -1;
242 	}
243 
244 	return (pid_t)n;
245 }
246 
247 static void
248 nosig(const char *name)
249 {
250 
251 	warnx("unknown signal %s; valid signals:", name);
252 	printsignals(stderr);
253 	exit(1);
254 	/* NOTREACHED */
255 }
256 
257 static void
258 printsignals(FILE *fp)
259 {
260 	int sig;
261 	int len, nl, pad;
262 	const char *name;
263 	int termwidth = 80;
264 
265 	if ((name = getenv("COLUMNS")) != 0)
266 		termwidth = atoi(name);
267 	else if (isatty(fileno(fp))) {
268 		struct winsize win;
269 
270 		if (ioctl(fileno(fp), TIOCGWINSZ, &win) == 0 && win.ws_col > 0)
271 			termwidth = win.ws_col;
272 	}
273 
274 	for (pad = 0, len = 0, sig = 0; (sig = signalnext(sig)) != 0; ) {
275 		name = signalname(sig);
276 		if (name == NULL)
277 			continue;
278 
279 		nl = strlen(name);
280 
281 		if (len > 0 && nl + len + pad >= termwidth) {
282 			fprintf(fp, "\n");
283 			len = 0;
284 			pad = 0;
285 		} else if (pad > 0 && len != 0)
286 			fprintf(fp, "%*s", pad, "");
287 		else
288 			pad = 0;
289 
290 		len += nl + pad;
291 		pad = (nl | 7) + 1 - nl;
292 
293 		fprintf(fp, "%s", name);
294 	}
295 	if (len != 0)
296 		fprintf(fp, "\n");
297 }
298 
299 static void
300 usage(void)
301 {
302 	const char *pn = getprogname();
303 
304 	fprintf(stderr, "usage: %s [-s signal_name] pid ...\n"
305 			"       %s -l [exit_status]\n"
306 			"       %s -signal_name pid ...\n"
307 			"       %s -signal_number pid ...\n",
308 	    pn, pn, pn, pn);
309 	exit(1);
310 	/* NOTREACHED */
311 }
312