procps/pgrep.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini pgrep/pkill implementation for busybox
   4  *
   5  * Copyright (C) 2007 Loic Grenie <loic.grenie@gmail.com>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9 //config:config PGREP
  10 //config:       bool "pgrep"
  11 //config:       default y
  12 //config:       help
  13 //config:         Look for processes by name.
  14 //config:
  15 //config:config PKILL
  16 //config:       bool "pkill"
  17 //config:       default y
  18 //config:       help
  19 //config:         Send signals to processes by name.
  20
  21 //applet:IF_PGREP(APPLET(pgrep, BB_DIR_USR_BIN, BB_SUID_DROP))
  22 //applet:IF_PKILL(APPLET_ODDNAME(pkill, pgrep, BB_DIR_USR_BIN, BB_SUID_DROP, pkill))
  23
  24 //kbuild:lib-$(CONFIG_PGREP) += pgrep.o
  25 //kbuild:lib-$(CONFIG_PKILL) += pgrep.o
  26
  27 //usage:#define pgrep_trivial_usage
  28 //usage:       "[-flnovx] [-s SID|-P PPID|PATTERN]"
  29 //usage:#define pgrep_full_usage "\n\n"
  30 //usage:       "Display process(es) selected by regex PATTERN\n"
  31 //usage:     "\n        -l      Show command name too"
  32 //usage:     "\n        -f      Match against entire command line"
  33 //usage:     "\n        -n      Show the newest process only"
  34 //usage:     "\n        -o      Show the oldest process only"
  35 //usage:     "\n        -v      Negate the match"
  36 //usage:     "\n        -x      Match whole name (not substring)"
  37 //usage:     "\n        -s      Match session ID (0 for current)"
  38 //usage:     "\n        -P      Match parent process ID"
  39 //usage:
  40 //usage:#define pkill_trivial_usage
  41 //usage:       "[-l|-SIGNAL] [-fnovx] [-s SID|-P PPID|PATTERN]"
  42 //usage:#define pkill_full_usage "\n\n"
  43 //usage:       "Send a signal to process(es) selected by regex PATTERN\n"
  44 //usage:     "\n        -l      List all signals"
  45 //usage:     "\n        -f      Match against entire command line"
  46 //usage:     "\n        -n      Signal the newest process only"
  47 //usage:     "\n        -o      Signal the oldest process only"
  48 //usage:     "\n        -v      Negate the match"
  49 //usage:     "\n        -x      Match whole name (not substring)"
  50 //usage:     "\n        -s      Match session ID (0 for current)"
  51 //usage:     "\n        -P      Match parent process ID"
  52
  53 #include "libbb.h"
  54 #include "xregex.h"
  55
  56 /* Idea taken from kill.c */
  57 #define pgrep (ENABLE_PGREP && applet_name[1] == 'g')
  58 #define pkill (ENABLE_PKILL && applet_name[1] == 'k')
  59
  60 enum {
  61         /* "vlfxons:P:" */
  62         OPTBIT_V = 0, /* must be first, we need OPT_INVERT = 0/1 */
  63         OPTBIT_L,
  64         OPTBIT_F,
  65         OPTBIT_X,
  66         OPTBIT_O,
  67         OPTBIT_N,
  68         OPTBIT_S,
  69         OPTBIT_P,
  70 };
  71
  72 #define OPT_INVERT      (opt & (1 << OPTBIT_V))
  73 #define OPT_LIST        (opt & (1 << OPTBIT_L))
  74 #define OPT_FULL        (opt & (1 << OPTBIT_F))
  75 #define OPT_ANCHOR      (opt & (1 << OPTBIT_X))
  76 #define OPT_FIRST       (opt & (1 << OPTBIT_O))
  77 #define OPT_LAST        (opt & (1 << OPTBIT_N))
  78 #define OPT_SID         (opt & (1 << OPTBIT_S))
  79 #define OPT_PPID        (opt & (1 << OPTBIT_P))
  80
  81 static void act(unsigned pid, char *cmd, int signo)
  82 {
  83         if (pgrep) {
  84                 if (option_mask32 & (1 << OPTBIT_L)) /* OPT_LIST */
  85                         printf("%u %s\n", pid, cmd);
  86                 else
  87                         printf("%u\n", pid);
  88         } else
  89                 kill(pid, signo);
  90 }
  91
  92 int pgrep_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  93 int pgrep_main(int argc UNUSED_PARAM, char **argv)
  94 {
  95         unsigned pid;
  96         int signo;
  97         unsigned opt;
  98         int scan_mask;
  99         int matched_pid;
 100         int sid2match, ppid2match;
 101         char *cmd_last;
 102         procps_status_t *proc;
 103         /* These are initialized to 0 */
 104         struct {
 105                 regex_t re_buffer;
 106                 regmatch_t re_match[1];
 107         } Z;
 108 #define re_buffer (Z.re_buffer)
 109 #define re_match  (Z.re_match )
 110
 111         memset(&Z, 0, sizeof(Z));
 112
 113         /* Parse -SIGNAL for pkill. Must be first option, if present */
 114         signo = SIGTERM;
 115         if (pkill && argv[1] && argv[1][0] == '-') {
 116                 int temp = get_signum(argv[1]+1);
 117                 if (temp != -1) {
 118                         signo = temp;
 119                         argv++;
 120                 }
 121         }
 122
 123         /* Parse remaining options */
 124         ppid2match = -1;
 125         sid2match = -1;
 126         opt = getopt32(argv, "vlfxons:+P:+", &sid2match, &ppid2match);
 127         argv += optind;
 128
 129         if (pkill && OPT_LIST) { /* -l: print the whole signal list */
 130                 print_signames();
 131                 return 0;
 132         }
 133
 134         pid = getpid();
 135         if (sid2match == 0)
 136                 sid2match = getsid(pid);
 137
 138         scan_mask = PSSCAN_COMM | PSSCAN_ARGV0;
 139         if (OPT_FULL)
 140                 scan_mask |= PSSCAN_ARGVN;
 141
 142         /* One pattern is required, if no -s and no -P */
 143         if ((sid2match & ppid2match) < 0 && (!argv[0] || argv[1]))
 144                 bb_show_usage();
 145
 146         if (argv[0])
 147                 xregcomp(&re_buffer, argv[0], OPT_ANCHOR ? REG_EXTENDED : (REG_EXTENDED|REG_NOSUB));
 148
 149         matched_pid = 0;
 150         cmd_last = NULL;
 151         proc = NULL;
 152         while ((proc = procps_scan(proc, scan_mask)) != NULL) {
 153                 char *cmd;
 154
 155                 if (proc->pid == pid)
 156                         continue;
 157
 158                 cmd = proc->argv0;
 159                 if (!cmd) {
 160                         cmd = proc->comm;
 161                 } else {
 162                         int i = proc->argv_len;
 163                         while (--i >= 0) {
 164                                 if ((unsigned char)cmd[i] < ' ')
 165                                         cmd[i] = ' ';
 166                         }
 167                 }
 168
 169                 if (ppid2match >= 0 && ppid2match != proc->ppid)
 170                         continue;
 171                 if (sid2match >= 0  && sid2match != proc->sid)
 172                         continue;
 173
 174                 /* NB: OPT_INVERT is always 0 or 1 */
 175                 if (!argv[0]
 176                  || (regexec(&re_buffer, cmd, 1, re_match, 0) == 0 /* match found */
 177                     && (!OPT_ANCHOR || (re_match[0].rm_so == 0 && re_match[0].rm_eo == (regoff_t)strlen(cmd)))
 178                     ) ^ OPT_INVERT
 179                 ) {
 180                         matched_pid = proc->pid;
 181                         if (OPT_LAST) {
 182                                 free(cmd_last);
 183                                 cmd_last = xstrdup(cmd);
 184                                 continue;
 185                         }
 186                         act(proc->pid, cmd, signo);
 187                         if (OPT_FIRST)
 188                                 break;
 189                 }
 190         }
 191
 192         if (cmd_last) {
 193                 act(matched_pid, cmd_last, signo);
 194                 if (ENABLE_FEATURE_CLEAN_UP)
 195                         free(cmd_last);
 196         }
 197         return matched_pid == 0; /* return 1 if no processes listed/signaled */
 198 }