xref: /freebsd/bin/kill/kill.c (revision 54d2737e7fe48226c908dcccfbda2ca1c08e07fc)
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 #include <ctype.h>
37 #include <err.h>
38 #include <errno.h>
39 #include <signal.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #ifdef SHELL
45 #define main killcmd
46 #include "bltin/bltin.h"
47 #endif
48 
49 static void nosig(const char *);
50 static void printsignals(FILE *);
51 static void usage(void) __dead2;
52 
53 int
54 main(int argc, char *argv[])
55 {
56 	char signame[SIG2STR_MAX];
57 	long pidl;
58 	pid_t pid;
59 	int errors, numsig, ret;
60 	char *ep;
61 
62 	if (argc < 2)
63 		usage();
64 
65 	numsig = SIGTERM;
66 
67 	argc--, argv++;
68 	if (!strcmp(*argv, "-l")) {
69 		argc--, argv++;
70 		if (argc > 1)
71 			usage();
72 		if (argc == 1) {
73 			if (!isdigit(**argv))
74 				usage();
75 			numsig = strtol(*argv, &ep, 10);
76 			if (!**argv || *ep)
77 				errx(2, "invalid signal number: %s", *argv);
78 			if (numsig >= 128)
79 				numsig -= 128;
80 			if (sig2str(numsig, signame) < 0)
81 				nosig(*argv);
82 			printf("%s\n", signame);
83 			return (0);
84 		}
85 		printsignals(stdout);
86 		return (0);
87 	}
88 
89 	if (!strcmp(*argv, "-s")) {
90 		argc--, argv++;
91 		if (argc < 1) {
92 			warnx("option requires an argument -- s");
93 			usage();
94 		}
95 		if (strcmp(*argv, "0") == 0)
96 			numsig = 0;
97 		else if (str2sig(*argv, &numsig) < 0)
98 			nosig(*argv);
99 		argc--, argv++;
100 	} else if (**argv == '-' && *(*argv + 1) != '-') {
101 		++*argv;
102 		if (str2sig(*argv, &numsig) < 0)
103 			nosig(*argv);
104 		argc--, argv++;
105 	}
106 
107 	if (argc > 0 && strncmp(*argv, "--", 2) == 0)
108 		argc--, argv++;
109 
110 	if (argc == 0)
111 		usage();
112 
113 	for (errors = 0; argc; argc--, argv++) {
114 #ifdef SHELL
115 		if (**argv == '%')
116 			ret = killjob(*argv, numsig);
117 		else
118 #endif
119 		{
120 			pidl = strtol(*argv, &ep, 10);
121 			/* Check for overflow of pid_t. */
122 			pid = (pid_t)pidl;
123 			if (!**argv || *ep || pid != pidl)
124 				errx(2, "illegal process id: %s", *argv);
125 			ret = kill(pid, numsig);
126 		}
127 		if (ret == -1) {
128 			warn("%s", *argv);
129 			errors = 1;
130 		}
131 	}
132 
133 	return (errors);
134 }
135 
136 static void
137 nosig(const char *name)
138 {
139 
140 	warnx("unknown signal %s; valid signals:", name);
141 	printsignals(stderr);
142 #ifdef SHELL
143 	error(NULL);
144 #else
145 	exit(2);
146 #endif
147 }
148 
149 static void
150 printsignals(FILE *fp)
151 {
152 	int n;
153 
154 	for (n = 1; n < sys_nsig; n++) {
155 		(void)fprintf(fp, "%s", sys_signame[n]);
156 		if (n == (sys_nsig / 2) || n == (sys_nsig - 1))
157 			(void)fprintf(fp, "\n");
158 		else
159 			(void)fprintf(fp, " ");
160 	}
161 }
162 
163 static void
164 usage(void)
165 {
166 
167 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
168 		"usage: kill [-s signal_name] pid ...",
169 		"       kill -l [exit_status]",
170 		"       kill -signal_name pid ...",
171 		"       kill -signal_number pid ...");
172 #ifdef SHELL
173 	error(NULL);
174 #else
175 	exit(2);
176 #endif
177 }
178