procps/kill.c

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