xref: /freebsd/bin/kill/kill.c (revision 97759ccc715c4b365432c16d763c50eecfcb1100)
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 #endif
44 #include <sys/cdefs.h>
45 #include <ctype.h>
46 #include <err.h>
47 #include <errno.h>
48 #include <signal.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 
53 #ifdef SHELL
54 #define main killcmd
55 #include "bltin/bltin.h"
56 #endif
57 
58 static void nosig(const char *);
59 static void printsignals(FILE *);
60 static int signame_to_signum(const char *);
61 static void usage(void) __dead2;
62 
63 int
64 main(int argc, char *argv[])
65 {
66 	long pidl;
67 	pid_t pid;
68 	int errors, numsig, ret;
69 	char *ep;
70 
71 	if (argc < 2)
72 		usage();
73 
74 	numsig = SIGTERM;
75 
76 	argc--, argv++;
77 	if (!strcmp(*argv, "-l")) {
78 		argc--, argv++;
79 		if (argc > 1)
80 			usage();
81 		if (argc == 1) {
82 			if (!isdigit(**argv))
83 				usage();
84 			numsig = strtol(*argv, &ep, 10);
85 			if (!**argv || *ep)
86 				errx(2, "illegal signal number: %s", *argv);
87 			if (numsig >= 128)
88 				numsig -= 128;
89 			if (numsig <= 0 || numsig >= sys_nsig)
90 				nosig(*argv);
91 			printf("%s\n", sys_signame[numsig]);
92 			return (0);
93 		}
94 		printsignals(stdout);
95 		return (0);
96 	}
97 
98 	if (!strcmp(*argv, "-s")) {
99 		argc--, argv++;
100 		if (argc < 1) {
101 			warnx("option requires an argument -- s");
102 			usage();
103 		}
104 		if (strcmp(*argv, "0")) {
105 			if ((numsig = signame_to_signum(*argv)) < 0)
106 				nosig(*argv);
107 		} else
108 			numsig = 0;
109 		argc--, argv++;
110 	} else if (**argv == '-' && *(*argv + 1) != '-') {
111 		++*argv;
112 		if (isalpha(**argv)) {
113 			if ((numsig = signame_to_signum(*argv)) < 0)
114 				nosig(*argv);
115 		} else if (isdigit(**argv)) {
116 			numsig = strtol(*argv, &ep, 10);
117 			if (!**argv || *ep)
118 				errx(2, "illegal signal number: %s", *argv);
119 			if (numsig < 0)
120 				nosig(*argv);
121 		} else
122 			nosig(*argv);
123 		argc--, argv++;
124 	}
125 
126 	if (argc > 0 && strncmp(*argv, "--", 2) == 0)
127 		argc--, argv++;
128 
129 	if (argc == 0)
130 		usage();
131 
132 	for (errors = 0; argc; argc--, argv++) {
133 #ifdef SHELL
134 		if (**argv == '%')
135 			ret = killjob(*argv, numsig);
136 		else
137 #endif
138 		{
139 			pidl = strtol(*argv, &ep, 10);
140 			/* Check for overflow of pid_t. */
141 			pid = (pid_t)pidl;
142 			if (!**argv || *ep || pid != pidl)
143 				errx(2, "illegal process id: %s", *argv);
144 			ret = kill(pid, numsig);
145 		}
146 		if (ret == -1) {
147 			warn("%s", *argv);
148 			errors = 1;
149 		}
150 	}
151 
152 	return (errors);
153 }
154 
155 static int
156 signame_to_signum(const char *sig)
157 {
158 	int n;
159 
160 	if (strncasecmp(sig, "SIG", 3) == 0)
161 		sig += 3;
162 	for (n = 1; n < sys_nsig; n++) {
163 		if (!strcasecmp(sys_signame[n], sig))
164 			return (n);
165 	}
166 	return (-1);
167 }
168 
169 static void
170 nosig(const char *name)
171 {
172 
173 	warnx("unknown signal %s; valid signals:", name);
174 	printsignals(stderr);
175 #ifdef SHELL
176 	error(NULL);
177 #else
178 	exit(2);
179 #endif
180 }
181 
182 static void
183 printsignals(FILE *fp)
184 {
185 	int n;
186 
187 	for (n = 1; n < sys_nsig; n++) {
188 		(void)fprintf(fp, "%s", sys_signame[n]);
189 		if (n == (sys_nsig / 2) || n == (sys_nsig - 1))
190 			(void)fprintf(fp, "\n");
191 		else
192 			(void)fprintf(fp, " ");
193 	}
194 }
195 
196 static void
197 usage(void)
198 {
199 
200 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
201 		"usage: kill [-s signal_name] pid ...",
202 		"       kill -l [exit_status]",
203 		"       kill -signal_name pid ...",
204 		"       kill -signal_number pid ...");
205 #ifdef SHELL
206 	error(NULL);
207 #else
208 	exit(2);
209 #endif
210 }
211