summaryrefslogtreecommitdiffhomepage
path: root/procps/kill.c
blob: e418046e7098ad101e4afcbd24e3cf80fa84a974 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/* vi: set sw=4 ts=4: */
/*
 * Mini kill/killall[5] implementation for busybox
 *
 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "libbb.h"

/* Note: kill_main is directly called from shell in order to implement
 * kill built-in. Shell substitutes job ids with process groups first.
 *
 * This brings some complications:
 *
 * + we can't use xfunc here
 * + we can't use applet_name
 * + we can't use bb_show_usage
 * (Above doesn't apply for killall[5] cases)
 *
 * kill %n gets translated into kill ' -<process group>' by shell (note space!)
 * This is needed to avoid collision with kill -9 ... syntax
 */

int kill_main(int argc, char **argv)
{
	char *arg;
	pid_t pid;
	int signo = SIGTERM, errors = 0, quiet = 0;
#if !ENABLE_KILLALL && !ENABLE_KILLALL5
#define killall 0
#define killall5 0
#else
/* How to determine who we are? find 3rd char from the end:
 * kill, killall, killall5
 *  ^i       ^a        ^l  - it's unique
 * (checking from the start is complicated by /bin/kill... case) */
	const char char3 = argv[0][strlen(argv[0]) - 3];
#define killall (ENABLE_KILLALL && char3 == 'a')
#define killall5 (ENABLE_KILLALL5 && char3 == 'l')
#endif

	/* Parse any options */
	argc--;
	arg = *++argv;

	if (argc < 1 || arg[0] != '-') {
		goto do_it_now;
	}

	/* The -l option, which prints out signal names.
	 * Intended usage in shell:
	 * echo "Died of SIG`kill -l $?`"
	 * We try to mimic what kill from coreutils-6.8 does */
	if (arg[1] == 'l' && arg[2] == '\0') {
		if (argc == 1) {
			/* Print the whole signal list */
			print_signames();
			return 0;
		}
		/* -l <sig list> */
		while ((arg = *++argv)) {
			if (isdigit(arg[0])) {
				signo = bb_strtou(arg, NULL, 10);
				if (errno) {
					bb_error_msg("unknown signal '%s'", arg);
					return EXIT_FAILURE;
				}
				/* Exitcodes >= 0x80 are to be treated
				 * as "killed by signal (exitcode & 0x7f)" */
				puts(get_signame(signo & 0x7f));
				/* TODO: 'bad' signal# - coreutils says:
				 * kill: 127: invalid signal
				 * we just print "127" instead */
			} else {
				signo = get_signum(arg);
				if (signo < 0) {
					bb_error_msg("unknown signal '%s'", arg);
					return EXIT_FAILURE;
				}
				printf("%d\n", signo);
			}
		}
		/* If they specified -l, we are all done */
		return EXIT_SUCCESS;
	}

	/* The -q quiet option */
	if (killall && arg[1] == 'q' && arg[2] == '\0') {
		quiet = 1;
		arg = *++argv;
		argc--;
		if (argc < 1)
			bb_show_usage();
		if (arg[0] != '-')
			goto do_it_now;
	}

	arg++; /* skip '-' */

	/* -o PID? (if present, it always is at the end of command line) */
	if (killall5 && arg[0] == 'o')
		goto do_it_now;

	if (argc > 1 && arg[0] == 's' && arg[1] == '\0') { /* -s SIG? */
		argc--;
		arg = *++argv;
	} /* else it must be -SIG */
	signo = get_signum(arg);
	if (signo < 0) { /* || signo > MAX_SIGNUM ? */
		bb_error_msg("bad signal name '%s'", arg);
		return EXIT_FAILURE;
	}
	arg = *++argv;
	argc--;

 do_it_now:
	pid = getpid();

	if (killall5) {
		pid_t sid;
		procps_status_t* p = NULL;
		int ret = 0;

		/* Find out our session id */
		sid = getsid(pid);
		/* Stop all processes */
		kill(-1, SIGSTOP);
		/* Signal all processes except those in our session */
		while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID))) {
			int i;

			if (p->sid == (unsigned)sid
			 || p->pid == (unsigned)pid
			 || p->pid == 1)
				continue;

			/* All remaining args must be -o PID options.
			 * Check p->pid against them. */
			for (i = 0; i < argc; i++) {
				pid_t omit;

				arg = argv[i];
				if (arg[0] != '-' || arg[1] != 'o') {
					bb_error_msg("bad option '%s'", arg);
					ret = 1;
					goto resume;
				}
				arg += 2;
				if (!arg[0] && argv[++i])
					arg = argv[i];
				omit = bb_strtoi(arg, NULL, 10);
				if (errno) {
					bb_error_msg("bad pid '%s'", arg);
					ret = 1;
					goto resume;
				}
				if (p->pid == omit)
					goto dont_kill;
			}
			kill(p->pid, signo);
 dont_kill: ;
		}
 resume:
		/* And let them continue */
		kill(-1, SIGCONT);
		return ret;
	}

	/* Pid or name is required for kill/killall */
	if (argc < 1) {
		bb_error_msg("you need to specify whom to kill");
		return EXIT_FAILURE;
	}

	if (killall) {
		/* Looks like they want to do a killall.  Do that */
		while (arg) {
			pid_t* pidList;

			pidList = find_pid_by_name(arg);
			if (*pidList == 0) {
				errors++;
				if (!quiet)
					bb_error_msg("%s: no process killed", arg);
			} else {
				pid_t *pl;

				for (pl = pidList; *pl; pl++) {
					if (*pl == pid)
						continue;
					if (kill(*pl, signo) == 0)
						continue;
					errors++;
					if (!quiet)
						bb_perror_msg("can't kill pid %u", (unsigned)*pl);
				}
			}
			free(pidList);
			arg = *++argv;
		}
		return errors;
	}

	/* Looks like they want to do a kill. Do that */
	while (arg) {
		/* Support shell 'space' trick */
		if (arg[0] == ' ')
			arg++;
		pid = bb_strtoi(arg, NULL, 10);
		if (errno) {
			bb_error_msg("bad pid '%s'", arg);
			errors++;
		} else if (kill(pid, signo) != 0) {
			bb_perror_msg("can't kill pid %d", (int)pid);
			errors++;
		}
		arg = *++argv;
	}
	return errors;
}