util-linux/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)
  96                         bb_show_usage();
  97                 if (arg[0] != '-')
  98                         goto do_it_now;
  99         }
 100
 101         arg++; /* skip '-' */
 102
 103         /* -o PID? (if present, it always is at the end of command line) */
 104         if (killall5 && arg[0] == 'o')
 105                 goto do_it_now;
 106
 107         if (argc > 1 && arg[0] == 's' && arg[1] == '\0') { /* -s SIG? */
 108                 argc--;
 109                 arg = *++argv;
 110         } /* else it must be -SIG */
 111         signo = get_signum(arg);
 112         if (signo < 0) { /* || signo > MAX_SIGNUM ? */
 113                 bb_error_msg("bad signal name '%s'", arg);
 114                 return EXIT_FAILURE;
 115         }
 116         arg = *++argv;
 117         argc--;
 118
 119  do_it_now:
 120         pid = getpid();
 121
 122         if (killall5) {
 123                 pid_t sid;
 124                 procps_status_t* p = NULL;
 125                 int ret = 0;
 126
 127                 /* Find out our session id */
 128                 sid = getsid(pid);
 129                 /* Stop all processes */
 130                 kill(-1, SIGSTOP);
 131                 /* Signal all processes except those in our session */
 132                 while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID))) {
 133                         int i;
 134
 135                         if (p->sid == (unsigned)sid
 136                          || p->pid == (unsigned)pid
 137                          || p->pid == 1)
 138                                 continue;
 139
 140                         /* All remaining args must be -o PID options.
 141                          * Check p->pid against them. */
 142                         for (i = 0; i < argc; i++) {
 143                                 pid_t omit;
 144
 145                                 arg = argv[i];
 146                                 if (arg[0] != '-' || arg[1] != 'o') {
 147                                         bb_error_msg("bad option '%s'", arg);
 148                                         ret = 1;
 149                                         goto resume;
 150                                 }
 151                                 arg += 2;
 152                                 if (!arg[0] && argv[++i])
 153                                         arg = argv[i];
 154                                 omit = bb_strtoi(arg, NULL, 10);
 155                                 if (errno) {
 156                                         bb_error_msg("bad pid '%s'", arg);
 157                                         ret = 1;
 158                                         goto resume;
 159                                 }
 160                                 if (p->pid == omit)
 161                                         goto dont_kill;
 162                         }
 163                         kill(p->pid, signo);
 164  dont_kill: ;
 165                 }
 166  resume:
 167                 /* And let them continue */
 168                 kill(-1, SIGCONT);
 169                 return ret;
 170         }
 171
 172         /* Pid or name is required for kill/killall */
 173         if (argc < 1) {
 174                 bb_error_msg("you need to specify whom to kill");
 175                 return EXIT_FAILURE;
 176         }
 177
 178         if (killall) {
 179                 /* Looks like they want to do a killall.  Do that */
 180                 while (arg) {
 181                         pid_t* pidList;
 182
 183                         pidList = find_pid_by_name(arg);
 184                         if (*pidList == 0) {
 185                                 errors++;
 186                                 if (!quiet)
 187                                         bb_error_msg("%s: no process killed", arg);
 188                         } else {
 189                                 pid_t *pl;
 190
 191                                 for (pl = pidList; *pl; pl++) {
 192                                         if (*pl == pid)
 193                                                 continue;
 194                                         if (kill(*pl, signo) == 0)
 195                                                 continue;
 196                                         errors++;
 197                                         if (!quiet)
 198                                                 bb_perror_msg("can't kill pid %d", (int)*pl);
 199                                 }
 200                         }
 201                         free(pidList);
 202                         arg = *++argv;
 203                 }
 204                 return errors;
 205         }
 206
 207         /* Looks like they want to do a kill. Do that */
 208         while (arg) {
 209                 /* Support shell 'space' trick */
 210                 if (arg[0] == ' ')
 211                         arg++;
 212                 pid = bb_strtoi(arg, NULL, 10);
 213                 if (errno) {
 214                         bb_error_msg("bad pid '%s'", arg);
 215                         errors++;
 216                 } else if (kill(pid, signo) != 0) {
 217                         bb_perror_msg("can't kill pid %d", (int)pid);
 218                         errors++;
 219                 }
 220                 arg = *++argv;
 221         }
 222         return errors;
 223 }