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 the GPL v2 or later, see the file LICENSE in this tarball.
   9  */
  10
  11 #include "libbb.h"
  12
  13 /* Note: kill_main is directly called from shell in order to implement
  14  * kill built-in. Shell substitutes job ids with process groups first.
  15  *
  16  * This brings some complications:
  17  *
  18  * + we can't use xfunc here
  19  * + we can't use applet_name
  20  * + we can't use bb_show_usage
  21  * (Above doesn't apply for killall[5] cases)
  22  *
  23  * kill %n gets translated into kill ' -<process group>' by shell (note space!)
  24  * This is needed to avoid collision with kill -9 ... syntax
  25  */
  26
  27 int kill_main(int argc, char **argv)
  28 {
  29         char *arg;
  30         pid_t pid;
  31         int signo = SIGTERM, errors = 0, quiet = 0;
  32 #if !ENABLE_KILLALL && !ENABLE_KILLALL5
  33 #define killall 0
  34 #define killall5 0
  35 #else
  36 /* How to determine who we are? find 3rd char from the end:
  37  * kill, killall, killall5
  38  *  ^i       ^a        ^l  - it's unique
  39  * (checking from the start is complicated by /bin/kill... case) */
  40         const char char3 = argv[0][strlen(argv[0]) - 3];
  41 #define killall (ENABLE_KILLALL && char3 == 'a')
  42 #define killall5 (ENABLE_KILLALL5 && char3 == 'l')
  43 #endif
  44
  45         /* Parse any options */
  46         argc--;
  47         arg = *++argv;
  48
  49         if (argc < 1 || arg[0] != '-') {
  50                 goto do_it_now;
  51         }
  52
  53         /* The -l option, which prints out signal names.
  54          * Intended usage in shell:
  55          * echo "Died of SIG`kill -l $?`"
  56          * We try to mimic what kill from coreutils-6.8 does */
  57         if (arg[1] == 'l' && arg[2] == '\0') {
  58                 if (argc == 1) {
  59                         /* Print the whole signal list */
  60                         print_signames();
  61                         return 0;
  62                 }
  63                 /* -l <sig list> */
  64                 while ((arg = *++argv)) {
  65                         if (isdigit(arg[0])) {
  66                                 signo = bb_strtou(arg, NULL, 10);
  67                                 if (errno) {
  68                                         bb_error_msg("unknown signal '%s'", arg);
  69                                         return EXIT_FAILURE;
  70                                 }
  71                                 /* Exitcodes >= 0x80 are to be treated
  72                                  * as "killed by signal (exitcode & 0x7f)" */
  73                                 puts(get_signame(signo & 0x7f));
  74                                 /* TODO: 'bad' signal# - coreutils says:
  75                                  * kill: 127: invalid signal
  76                                  * we just print "127" instead */
  77                         } else {
  78                                 signo = get_signum(arg);
  79                                 if (signo < 0) {
  80                                         bb_error_msg("unknown signal '%s'", arg);
  81                                         return EXIT_FAILURE;
  82                                 }
  83                                 printf("%d\n", signo);
  84                         }
  85                 }
  86                 /* If they specified -l, we are all done */
  87                 return EXIT_SUCCESS;
  88         }
  89
  90         /* The -q quiet option */
  91         if (killall && arg[1] == 'q' && arg[2] == '\0') {
  92                 quiet = 1;
  93                 arg = *++argv;
  94                 argc--;
  95                 if (argc < 1) bb_show_usage();
  96                 if (arg[0] != '-') goto do_it_now;
  97         }
  98
  99         /* -SIG */
 100         signo = get_signum(&arg[1]);
 101         if (signo < 0) { /* || signo > MAX_SIGNUM ? */
 102                 bb_error_msg("bad signal name '%s'", &arg[1]);
 103                 return EXIT_FAILURE;
 104         }
 105         arg = *++argv;
 106         argc--;
 107
 108 do_it_now:
 109         pid = getpid();
 110
 111         if (killall5) {
 112                 pid_t sid;
 113                 procps_status_t* p = NULL;
 114
 115                 /* Find out our own session id */
 116                 sid = getsid(pid);
 117                 /* Now stop all processes */
 118                 kill(-1, SIGSTOP);
 119                 /* Now kill all processes except our session */
 120                 while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID))) {
 121                         if (p->sid != (unsigned)sid && p->pid != (unsigned)pid && p->pid != 1)
 122                                 kill(p->pid, signo);
 123                 }
 124                 /* And let them continue */
 125                 kill(-1, SIGCONT);
 126                 return 0;
 127         }
 128
 129         /* Pid or name is required for kill/killall */
 130         if (argc < 1) {
 131                 bb_error_msg("you need to specify whom to kill");
 132                 return EXIT_FAILURE;
 133         }
 134
 135         if (killall) {
 136                 /* Looks like they want to do a killall.  Do that */
 137                 while (arg) {
 138                         pid_t* pidList;
 139
 140                         pidList = find_pid_by_name(arg);
 141                         if (*pidList == 0) {
 142                                 errors++;
 143                                 if (!quiet)
 144                                         bb_error_msg("%s: no process killed", arg);
 145                         } else {
 146                                 pid_t *pl;
 147
 148                                 for (pl = pidList; *pl; pl++) {
 149                                         if (*pl == pid)
 150                                                 continue;
 151                                         if (kill(*pl, signo) == 0)
 152                                                 continue;
 153                                         errors++;
 154                                         if (!quiet)
 155                                                 bb_perror_msg("cannot kill pid %u", (unsigned)*pl);
 156                                 }
 157                         }
 158                         free(pidList);
 159                         arg = *++argv;
 160                 }
 161                 return errors;
 162         }
 163
 164         /* Looks like they want to do a kill. Do that */
 165         while (arg) {
 166                 /* Support shell 'space' trick */
 167                 if (arg[0] == ' ')
 168                         arg++;
 169                 pid = bb_strtoi(arg, NULL, 10);
 170                 if (errno) {
 171                         bb_error_msg("bad pid '%s'", arg);
 172                         errors++;
 173                 } else if (kill(pid, signo) != 0) {
 174                         bb_perror_msg("cannot kill pid %d", (int)pid);
 175                         errors++;
 176                 }
 177                 arg = *++argv;
 178         }
 179         return errors;
 180 }