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1/* vi: set sw=4 ts=4: */
2/*
3 * Mini kill/killall[5] implementation for busybox
4 *
5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 *
8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9 */
10//config:config KILL
11//config: bool "kill"
12//config: default y
13//config: help
14//config: The command kill sends the specified signal to the specified
15//config: process or process group. If no signal is specified, the TERM
16//config: signal is sent.
17//config:
18//config:config KILLALL
19//config: bool "killall"
20//config: default y
21//config: help
22//config: killall sends a signal to all processes running any of the
23//config: specified commands. If no signal name is specified, SIGTERM is
24//config: sent.
25//config:
26//config:config KILLALL5
27//config: bool "killall5"
28//config: default y
29//config: help
30//config: The SystemV killall command. killall5 sends a signal
31//config: to all processes except kernel threads and the processes
32//config: in its own session, so it won't kill the shell that is running
33//config: the script it was called from.
34
35//applet:IF_KILL(APPLET(kill, BB_DIR_BIN, BB_SUID_DROP))
36//applet:IF_KILLALL(APPLET_ODDNAME(killall, kill, BB_DIR_USR_BIN, BB_SUID_DROP, killall))
37//applet:IF_KILLALL5(APPLET_ODDNAME(killall5, kill, BB_DIR_USR_SBIN, BB_SUID_DROP, killall5))
38
39//kbuild:lib-$(CONFIG_KILL) += kill.o
40//kbuild:lib-$(CONFIG_KILLALL) += kill.o
41//kbuild:lib-$(CONFIG_KILLALL5) += kill.o
42
43//usage:#define kill_trivial_usage
44//usage: "[-l] [-SIG] PID..."
45//usage:#define kill_full_usage "\n\n"
46//usage: "Send a signal (default: TERM) to given PIDs\n"
47//usage: "\n -l List all signal names and numbers"
48/* //usage: "\n -s SIG Yet another way of specifying SIG" */
49//usage:
50//usage:#define kill_example_usage
51//usage: "$ ps | grep apache\n"
52//usage: "252 root root S [apache]\n"
53//usage: "263 www-data www-data S [apache]\n"
54//usage: "264 www-data www-data S [apache]\n"
55//usage: "265 www-data www-data S [apache]\n"
56//usage: "266 www-data www-data S [apache]\n"
57//usage: "267 www-data www-data S [apache]\n"
58//usage: "$ kill 252\n"
59//usage:
60//usage:#define killall_trivial_usage
61//usage: "[-l] [-q] [-SIG] PROCESS_NAME..."
62//usage:#define killall_full_usage "\n\n"
63//usage: "Send a signal (default: TERM) to given processes\n"
64//usage: "\n -l List all signal names and numbers"
65/* //usage: "\n -s SIG Yet another way of specifying SIG" */
66//usage: "\n -q Don't complain if no processes were killed"
67//usage:
68//usage:#define killall_example_usage
69//usage: "$ killall apache\n"
70//usage:
71//usage:#define killall5_trivial_usage
72//usage: "[-l] [-SIG] [-o PID]..."
73//usage:#define killall5_full_usage "\n\n"
74//usage: "Send a signal (default: TERM) to all processes outside current session\n"
75//usage: "\n -l List all signal names and numbers"
76//usage: "\n -o PID Don't signal this PID"
77/* //usage: "\n -s SIG Yet another way of specifying SIG" */
78
79#include "libbb.h"
80
81/* Note: kill_main is directly called from shell in order to implement
82 * kill built-in. Shell substitutes job ids with process groups first.
83 *
84 * This brings some complications:
85 *
86 * + we can't use xfunc here
87 * + we can't use applet_name
88 * + we can't use bb_show_usage
89 * (Above doesn't apply for killall[5] cases)
90 *
91 * kill %n gets translated into kill ' -<process group>' by shell (note space!)
92 * This is needed to avoid collision with kill -9 ... syntax
93 */
94
95int kill_main(int argc UNUSED_PARAM, char **argv)
96{
97 char *arg;
98 pid_t pid;
99 int signo = SIGTERM, errors = 0, quiet = 0;
100#if ENABLE_KILL && !ENABLE_KILLALL && !ENABLE_KILLALL5
101# define killall 0
102# define killall5 0
103#elif !ENABLE_KILL && ENABLE_KILLALL && !ENABLE_KILLALL5
104# define killall 1
105# define killall5 0
106#elif !ENABLE_KILL && !ENABLE_KILLALL && ENABLE_KILLALL5
107# define killall 0
108# define killall5 1
109#else
110/* How to determine who we are? find 3rd char from the end:
111 * kill, killall, killall5
112 * ^i ^a ^l - it's unique
113 * (checking from the start is complicated by /bin/kill... case) */
114 const char char3 = argv[0][strlen(argv[0]) - 3];
115# define killall (ENABLE_KILLALL && char3 == 'a')
116# define killall5 (ENABLE_KILLALL5 && char3 == 'l')
117#endif
118
119 /* Parse any options */
120 arg = *++argv;
121
122 if (!arg || arg[0] != '-') {
123 goto do_it_now;
124 }
125
126 /* The -l option, which prints out signal names.
127 * Intended usage in shell:
128 * echo "Died of SIG`kill -l $?`"
129 * We try to mimic what kill from coreutils-6.8 does */
130 if (arg[1] == 'l' && arg[2] == '\0') {
131 arg = *++argv;
132 if (!arg) {
133 /* Print the whole signal list */
134 print_signames();
135 return 0;
136 }
137 /* -l <sig list> */
138 do {
139 if (isdigit(arg[0])) {
140 signo = bb_strtou(arg, NULL, 10);
141 if (errno) {
142 bb_error_msg("unknown signal '%s'", arg);
143 return EXIT_FAILURE;
144 }
145 /* Exitcodes >= 0x80 are to be treated
146 * as "killed by signal (exitcode & 0x7f)" */
147 puts(get_signame(signo & 0x7f));
148 /* TODO: 'bad' signal# - coreutils says:
149 * kill: 127: invalid signal
150 * we just print "127" instead */
151 } else {
152 signo = get_signum(arg);
153 if (signo < 0) {
154 bb_error_msg("unknown signal '%s'", arg);
155 return EXIT_FAILURE;
156 }
157 printf("%d\n", signo);
158 }
159 arg = *++argv;
160 } while (arg);
161 return EXIT_SUCCESS;
162 }
163
164 /* The -q quiet option */
165 if (killall && arg[1] == 'q' && arg[2] == '\0') {
166 quiet = 1;
167 arg = *++argv;
168 if (!arg)
169 bb_show_usage();
170 if (arg[0] != '-')
171 goto do_it_now;
172 }
173
174 arg++; /* skip '-' */
175
176 /* -o PID? (if present, it always is at the end of command line) */
177 if (killall5 && arg[0] == 'o')
178 goto do_it_now;
179
180 if (argv[1] && arg[0] == 's' && arg[1] == '\0') { /* -s SIG? */
181 arg = *++argv;
182 } /* else it must be -SIG */
183 signo = get_signum(arg);
184 if (signo < 0) { /* || signo > MAX_SIGNUM ? */
185 bb_error_msg("bad signal name '%s'", arg);
186 return EXIT_FAILURE;
187 }
188 arg = *++argv;
189
190 do_it_now:
191 pid = getpid();
192
193 if (killall5) {
194 pid_t sid;
195 procps_status_t* p = NULL;
196 /* compat: exitcode 2 is "no one was signaled" */
197 int ret = 2;
198
199 /* Find out our session id */
200 sid = getsid(pid);
201 /* Stop all processes */
202 if (signo != SIGSTOP && signo != SIGCONT)
203 kill(-1, SIGSTOP);
204 /* Signal all processes except those in our session */
205 while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID)) != NULL) {
206 char **args;
207
208 if (p->sid == (unsigned)sid
209 || p->sid == 0 /* compat: kernel thread, don't signal it */
210 || p->pid == (unsigned)pid
211 || p->pid == 1
212 ) {
213 continue;
214 }
215
216 /* All remaining args must be -o PID options.
217 * Check p->pid against them. */
218 args = argv;
219 while (*args) {
220 pid_t omit;
221
222 arg = *args++;
223 if (arg[0] != '-' || arg[1] != 'o') {
224 bb_error_msg("bad option '%s'", arg);
225 ret = 1;
226 goto resume;
227 }
228 arg += 2;
229 if (!arg[0] && *args)
230 arg = *args++;
231 omit = bb_strtoi(arg, NULL, 10);
232 if (errno) {
233 bb_error_msg("invalid number '%s'", arg);
234 ret = 1;
235 goto resume;
236 }
237 if ((pid_t) p->pid == (pid_t) omit)
238 goto dont_kill;
239 }
240 kill(p->pid, signo);
241 ret = 0;
242 dont_kill: ;
243 }
244 resume:
245 /* And let them continue */
246 if (signo != SIGSTOP && signo != SIGCONT)
247 kill(-1, SIGCONT);
248 return ret;
249 }
250
251 /* Pid or name is required for kill/killall */
252 if (!arg) {
253 bb_error_msg("you need to specify whom to kill");
254 return EXIT_FAILURE;
255 }
256
257 if (killall) {
258 /* Looks like they want to do a killall. Do that */
259 do {
260 pid_t* pidList;
261
262 pidList = find_pid_by_name(arg);
263 if (*pidList == 0) {
264 errors++;
265 if (!quiet)
266 bb_error_msg("%s: no process killed", arg);
267 } else {
268 pid_t *pl;
269
270 for (pl = pidList; *pl; pl++) {
271 if (*pl == pid)
272 continue;
273 if (kill(*pl, signo) == 0)
274 continue;
275 errors++;
276 if (!quiet)
277 bb_perror_msg("can't kill pid %d", (int)*pl);
278 }
279 }
280 free(pidList);
281 arg = *++argv;
282 } while (arg);
283 return errors;
284 }
285
286 /* Looks like they want to do a kill. Do that */
287 while (arg) {
288#if ENABLE_ASH || ENABLE_HUSH
289 /*
290 * We need to support shell's "hack formats" of
291 * " -PRGP_ID" (yes, with a leading space)
292 * and " PID1 PID2 PID3" (with degenerate case "")
293 */
294 while (*arg != '\0') {
295 char *end;
296 if (*arg == ' ')
297 arg++;
298 pid = bb_strtoi(arg, &end, 10);
299 if (errno && (errno != EINVAL || *end != ' ')) {
300 bb_error_msg("invalid number '%s'", arg);
301 errors++;
302 break;
303 }
304 if (kill(pid, signo) != 0) {
305 bb_perror_msg("can't kill pid %d", (int)pid);
306 errors++;
307 }
308 arg = end; /* can only point to ' ' or '\0' now */
309 }
310#else
311 pid = bb_strtoi(arg, NULL, 10);
312 if (errno) {
313 bb_error_msg("invalid number '%s'", arg);
314 errors++;
315 } else if (kill(pid, signo) != 0) {
316 bb_perror_msg("can't kill pid %d", (int)pid);
317 errors++;
318 }
319#endif
320 arg = *++argv;
321 }
322 return errors;
323}
324
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