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