xref: /freebsd/bin/kill/kill.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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  * Important: This file is used both as a standalone program /bin/kill and
33  * as a builtin for /bin/sh (#define SHELL).
34  */
35 
36 #if 0
37 #ifndef lint
38 static char const copyright[] =
39 "@(#) Copyright (c) 1988, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 static char sccsid[] = "@(#)kill.c	8.4 (Berkeley) 4/28/95";
45 #endif /* not lint */
46 #endif
47 #include <sys/cdefs.h>
48 #include <ctype.h>
49 #include <err.h>
50 #include <errno.h>
51 #include <signal.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 
56 #ifdef SHELL
57 #define main killcmd
58 #include "bltin/bltin.h"
59 #endif
60 
61 static void nosig(const char *);
62 static void printsignals(FILE *);
63 static int signame_to_signum(const char *);
64 static void usage(void) __dead2;
65 
66 int
67 main(int argc, char *argv[])
68 {
69 	long pidl;
70 	pid_t pid;
71 	int errors, numsig, ret;
72 	char *ep;
73 
74 	if (argc < 2)
75 		usage();
76 
77 	numsig = SIGTERM;
78 
79 	argc--, argv++;
80 	if (!strcmp(*argv, "-l")) {
81 		argc--, argv++;
82 		if (argc > 1)
83 			usage();
84 		if (argc == 1) {
85 			if (!isdigit(**argv))
86 				usage();
87 			numsig = strtol(*argv, &ep, 10);
88 			if (!**argv || *ep)
89 				errx(2, "illegal signal number: %s", *argv);
90 			if (numsig >= 128)
91 				numsig -= 128;
92 			if (numsig <= 0 || numsig >= sys_nsig)
93 				nosig(*argv);
94 			printf("%s\n", sys_signame[numsig]);
95 			return (0);
96 		}
97 		printsignals(stdout);
98 		return (0);
99 	}
100 
101 	if (!strcmp(*argv, "-s")) {
102 		argc--, argv++;
103 		if (argc < 1) {
104 			warnx("option requires an argument -- s");
105 			usage();
106 		}
107 		if (strcmp(*argv, "0")) {
108 			if ((numsig = signame_to_signum(*argv)) < 0)
109 				nosig(*argv);
110 		} else
111 			numsig = 0;
112 		argc--, argv++;
113 	} else if (**argv == '-' && *(*argv + 1) != '-') {
114 		++*argv;
115 		if (isalpha(**argv)) {
116 			if ((numsig = signame_to_signum(*argv)) < 0)
117 				nosig(*argv);
118 		} else if (isdigit(**argv)) {
119 			numsig = strtol(*argv, &ep, 10);
120 			if (!**argv || *ep)
121 				errx(2, "illegal signal number: %s", *argv);
122 			if (numsig < 0)
123 				nosig(*argv);
124 		} else
125 			nosig(*argv);
126 		argc--, argv++;
127 	}
128 
129 	if (argc > 0 && strncmp(*argv, "--", 2) == 0)
130 		argc--, argv++;
131 
132 	if (argc == 0)
133 		usage();
134 
135 	for (errors = 0; argc; argc--, argv++) {
136 #ifdef SHELL
137 		if (**argv == '%')
138 			ret = killjob(*argv, numsig);
139 		else
140 #endif
141 		{
142 			pidl = strtol(*argv, &ep, 10);
143 			/* Check for overflow of pid_t. */
144 			pid = (pid_t)pidl;
145 			if (!**argv || *ep || pid != pidl)
146 				errx(2, "illegal process id: %s", *argv);
147 			ret = kill(pid, numsig);
148 		}
149 		if (ret == -1) {
150 			warn("%s", *argv);
151 			errors = 1;
152 		}
153 	}
154 
155 	return (errors);
156 }
157 
158 static int
159 signame_to_signum(const char *sig)
160 {
161 	int n;
162 
163 	if (strncasecmp(sig, "SIG", 3) == 0)
164 		sig += 3;
165 	for (n = 1; n < sys_nsig; n++) {
166 		if (!strcasecmp(sys_signame[n], sig))
167 			return (n);
168 	}
169 	return (-1);
170 }
171 
172 static void
173 nosig(const char *name)
174 {
175 
176 	warnx("unknown signal %s; valid signals:", name);
177 	printsignals(stderr);
178 #ifdef SHELL
179 	error(NULL);
180 #else
181 	exit(2);
182 #endif
183 }
184 
185 static void
186 printsignals(FILE *fp)
187 {
188 	int n;
189 
190 	for (n = 1; n < sys_nsig; n++) {
191 		(void)fprintf(fp, "%s", sys_signame[n]);
192 		if (n == (sys_nsig / 2) || n == (sys_nsig - 1))
193 			(void)fprintf(fp, "\n");
194 		else
195 			(void)fprintf(fp, " ");
196 	}
197 }
198 
199 static void
200 usage(void)
201 {
202 
203 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
204 		"usage: kill [-s signal_name] pid ...",
205 		"       kill -l [exit_status]",
206 		"       kill -signal_name pid ...",
207 		"       kill -signal_number pid ...");
208 #ifdef SHELL
209 	error(NULL);
210 #else
211 	exit(2);
212 #endif
213 }
214