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, 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         argc--;
  83         arg = *++argv;
  84
  85         if (argc < 1 || arg[0] != '-') {
  86                 goto do_it_now;
  87         }
  88
  89         /* The -l option, which prints out signal names.
  90          * Intended usage in shell:
  91          * echo "Died of SIG`kill -l $?`"
  92          * We try to mimic what kill from coreutils-6.8 does */
  93         if (arg[1] == 'l' && arg[2] == '\0') {
  94                 if (argc == 1) {
  95                         /* Print the whole signal list */
  96                         print_signames();
  97                         return 0;
  98                 }
  99                 /* -l <sig list> */
 100                 while ((arg = *++argv)) {
 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                 }
 122                 /* If they specified -l, we are all done */
 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                 argc--;
 131                 if (argc < 1)
 132                         bb_show_usage();
 133                 if (arg[0] != '-')
 134                         goto do_it_now;
 135         }
 136
 137         arg++; /* skip '-' */
 138
 139         /* -o PID? (if present, it always is at the end of command line) */
 140         if (killall5 && arg[0] == 'o')
 141                 goto do_it_now;
 142
 143         if (argc > 1 && arg[0] == 's' && arg[1] == '\0') { /* -s SIG? */
 144                 argc--;
 145                 arg = *++argv;
 146         } /* else it must be -SIG */
 147         signo = get_signum(arg);
 148         if (signo < 0) { /* || signo > MAX_SIGNUM ? */
 149                 bb_error_msg("bad signal name '%s'", arg);
 150                 return EXIT_FAILURE;
 151         }
 152         arg = *++argv;
 153         argc--;
 154
 155  do_it_now:
 156         pid = getpid();
 157
 158         if (killall5) {
 159                 pid_t sid;
 160                 procps_status_t* p = NULL;
 161                 int ret = 0;
 162
 163                 /* Find out our session id */
 164                 sid = getsid(pid);
 165                 /* Stop all processes */
 166                 if (signo != SIGSTOP && signo != SIGCONT)
 167                         kill(-1, SIGSTOP);
 168                 /* Signal all processes except those in our session */
 169                 while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID)) != NULL) {
 170                         int i;
 171
 172                         if (p->sid == (unsigned)sid
 173                          || p->pid == (unsigned)pid
 174                          || p->pid == 1
 175                         ) {
 176                                 continue;
 177                         }
 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                 if (signo != SIGSTOP && signo != SIGCONT)
 208                         kill(-1, SIGCONT);
 209                 return ret;
 210         }
 211
 212         /* Pid or name is required for kill/killall */
 213         if (argc < 1) {
 214                 bb_error_msg("you need to specify whom to kill");
 215                 return EXIT_FAILURE;
 216         }
 217
 218         if (killall) {
 219                 /* Looks like they want to do a killall.  Do that */
 220                 while (arg) {
 221                         pid_t* pidList;
 222
 223                         pidList = find_pid_by_name(arg);
 224                         if (*pidList == 0) {
 225                                 errors++;
 226                                 if (!quiet)
 227                                         bb_error_msg("%s: no process killed", arg);
 228                         } else {
 229                                 pid_t *pl;
 230
 231                                 for (pl = pidList; *pl; pl++) {
 232                                         if (*pl == pid)
 233                                                 continue;
 234                                         if (kill(*pl, signo) == 0)
 235                                                 continue;
 236                                         errors++;
 237                                         if (!quiet)
 238                                                 bb_perror_msg("can't kill pid %d", (int)*pl);
 239                                 }
 240                         }
 241                         free(pidList);
 242                         arg = *++argv;
 243                 }
 244                 return errors;
 245         }
 246
 247         /* Looks like they want to do a kill. Do that */
 248         while (arg) {
 249 #if ENABLE_ASH || ENABLE_HUSH
 250                 /*
 251                  * We need to support shell's "hack formats" of
 252                  * " -PRGP_ID" (yes, with a leading space)
 253                  * and " PID1 PID2 PID3" (with degenerate case "")
 254                  */
 255                 while (*arg != '\0') {
 256                         char *end;
 257                         if (*arg == ' ')
 258                                 arg++;
 259                         pid = bb_strtoi(arg, &end, 10);
 260                         if (errno && (errno != EINVAL || *end != ' ')) {
 261                                 bb_error_msg("invalid number '%s'", arg);
 262                                 errors++;
 263                                 break;
 264                         }
 265                         if (kill(pid, signo) != 0) {
 266                                 bb_perror_msg("can't kill pid %d", (int)pid);
 267                                 errors++;
 268                         }
 269                         arg = end; /* can only point to ' ' or '\0' now */
 270                 }
 271 #else
 272                 pid = bb_strtoi(arg, NULL, 10);
 273                 if (errno) {
 274                         bb_error_msg("invalid number '%s'", arg);
 275                         errors++;
 276                 } else if (kill(pid, signo) != 0) {
 277                         bb_perror_msg("can't kill pid %d", (int)pid);
 278                         errors++;
 279                 }
 280 #endif
 281                 arg = *++argv;
 282         }
 283         return errors;
 284 }