src/kill.c

   1 /* kill -- send a signal to a process
   2    Copyright (C) 2002-2005, 2008-2012 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Paul Eggert.  */
  18
  19 #include <config.h>
  20 #include <stdio.h>
  21 #include <getopt.h>
  22 #include <sys/types.h>
  23 #include <signal.h>
  24
  25 #include "system.h"
  26 #include "error.h"
  27 #include "sig2str.h"
  28 #include "operand2sig.h"
  29
  30 /* The official name of this program (e.g., no `g' prefix).  */
  31 #define PROGRAM_NAME "kill"
  32
  33 #define AUTHORS proper_name ("Paul Eggert")
  34 \f
  35 #if ! (HAVE_DECL_STRSIGNAL || defined strsignal)
  36 # if ! (HAVE_DECL_SYS_SIGLIST || defined sys_siglist)
  37 #  if HAVE_DECL__SYS_SIGLIST || defined _sys_siglist
  38 #   define sys_siglist _sys_siglist
  39 #  elif HAVE_DECL___SYS_SIGLIST || defined __sys_siglist
  40 #   define sys_siglist __sys_siglist
  41 #  endif
  42 # endif
  43 # if HAVE_DECL_SYS_SIGLIST || defined sys_siglist
  44 #  define strsignal(signum) (0 <= (signum) && (signum) <= SIGNUM_BOUND \
  45                              ? sys_siglist[signum] \
  46                              : 0)
  47 # endif
  48 # ifndef strsignal
  49 #  define strsignal(signum) 0
  50 # endif
  51 #endif
  52 \f
  53 static char const short_options[] =
  54   "0::1::2::3::4::5::6::7::8::9::"
  55   "A::B::C::D::E::F::G::H::I::J::K::L::M::"
  56   "N::O::P::Q::R::S::T::U::V::W::X::Y::Z::"
  57   "ln:s:t";
  58
  59 static struct option const long_options[] =
  60 {
  61   {"list", no_argument, NULL, 'l'},
  62   {"signal", required_argument, NULL, 's'},
  63   {"table", no_argument, NULL, 't'},
  64   {GETOPT_HELP_OPTION_DECL},
  65   {GETOPT_VERSION_OPTION_DECL},
  66   {NULL, 0, NULL, 0}
  67 };
  68
  69 void
  70 usage (int status)
  71 {
  72   if (status != EXIT_SUCCESS)
  73     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  74              program_name);
  75   else
  76     {
  77       printf (_("\
  78 Usage: %s [-s SIGNAL | -SIGNAL] PID...\n\
  79   or:  %s -l [SIGNAL]...\n\
  80   or:  %s -t [SIGNAL]...\n\
  81 "),
  82               program_name, program_name, program_name);
  83       fputs (_("\
  84 Send signals to processes, or list signals.\n\
  85 \n\
  86 "), stdout);
  87       fputs (_("\
  88 Mandatory arguments to long options are mandatory for short options too.\n\
  89 "), stdout);
  90       fputs (_("\
  91   -s, --signal=SIGNAL, -SIGNAL\n\
  92                    specify the name or number of the signal to be sent\n\
  93   -l, --list       list signal names, or convert signal names to/from numbers\n\
  94   -t, --table      print a table of signal information\n\
  95 "), stdout);
  96       fputs (HELP_OPTION_DESCRIPTION, stdout);
  97       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  98       fputs (_("\n\
  99 SIGNAL may be a signal name like `HUP', or a signal number like `1',\n\
 100 or the exit status of a process terminated by a signal.\n\
 101 PID is an integer; if negative it identifies a process group.\n\
 102 "), stdout);
 103       printf (USAGE_BUILTIN_WARNING, PROGRAM_NAME);
 104       emit_ancillary_info ();
 105     }
 106   exit (status);
 107 }
 108 \f
 109 /* Print a row of `kill -t' output.  NUM_WIDTH is the maximum signal
 110    number width, and SIGNUM is the signal number to print.  The
 111    maximum name width is NAME_WIDTH, and SIGNAME is the name to print.  */
 112
 113 static void
 114 print_table_row (unsigned int num_width, int signum,
 115                  unsigned int name_width, char const *signame)
 116 {
 117   char const *description = strsignal (signum);
 118   printf ("%*d %-*s %s\n", num_width, signum, name_width, signame,
 119           description ? description : "?");
 120 }
 121
 122 /* Print a list of signal names.  If TABLE, print a table.
 123    Print the names specified by ARGV if nonzero; otherwise,
 124    print all known names.  Return a suitable exit status.  */
 125
 126 static int
 127 list_signals (bool table, char *const *argv)
 128 {
 129   int signum;
 130   int status = EXIT_SUCCESS;
 131   char signame[SIG2STR_MAX];
 132
 133   if (table)
 134     {
 135       unsigned int name_width = 0;
 136
 137       /* Compute the maximum width of a signal number.  */
 138       unsigned int num_width = 1;
 139       for (signum = 1; signum <= SIGNUM_BOUND / 10; signum *= 10)
 140         num_width++;
 141
 142       /* Compute the maximum width of a signal name.  */
 143       for (signum = 1; signum <= SIGNUM_BOUND; signum++)
 144         if (sig2str (signum, signame) == 0)
 145           {
 146             size_t len = strlen (signame);
 147             if (name_width < len)
 148               name_width = len;
 149           }
 150
 151       if (argv)
 152         for (; *argv; argv++)
 153           {
 154             signum = operand2sig (*argv, signame);
 155             if (signum < 0)
 156               status = EXIT_FAILURE;
 157             else
 158               print_table_row (num_width, signum, name_width, signame);
 159           }
 160       else
 161         for (signum = 1; signum <= SIGNUM_BOUND; signum++)
 162           if (sig2str (signum, signame) == 0)
 163             print_table_row (num_width, signum, name_width, signame);
 164     }
 165   else
 166     {
 167       if (argv)
 168         for (; *argv; argv++)
 169           {
 170             signum = operand2sig (*argv, signame);
 171             if (signum < 0)
 172               status = EXIT_FAILURE;
 173             else
 174               {
 175                 if (ISDIGIT (**argv))
 176                   puts (signame);
 177                 else
 178                   printf ("%d\n", signum);
 179               }
 180           }
 181       else
 182         for (signum = 1; signum <= SIGNUM_BOUND; signum++)
 183           if (sig2str (signum, signame) == 0)
 184             puts (signame);
 185     }
 186
 187   return status;
 188 }
 189 \f
 190 /* Send signal SIGNUM to all the processes or process groups specified
 191    by ARGV.  Return a suitable exit status.  */
 192
 193 static int
 194 send_signals (int signum, char *const *argv)
 195 {
 196   int status = EXIT_SUCCESS;
 197   char const *arg = *argv;
 198
 199   do
 200     {
 201       char *endp;
 202       intmax_t n = (errno = 0, strtoimax (arg, &endp, 10));
 203       pid_t pid = n;
 204
 205       if (errno == ERANGE || pid != n || arg == endp || *endp)
 206         {
 207           error (0, 0, _("%s: invalid process id"), arg);
 208           status = EXIT_FAILURE;
 209         }
 210       else if (kill (pid, signum) != 0)
 211         {
 212           error (0, errno, "%s", arg);
 213           status = EXIT_FAILURE;
 214         }
 215     }
 216   while ((arg = *++argv));
 217
 218   return status;
 219 }
 220 \f
 221 int
 222 main (int argc, char **argv)
 223 {
 224   int optc;
 225   bool list = false;
 226   bool table = false;
 227   int signum = -1;
 228   char signame[SIG2STR_MAX];
 229
 230   initialize_main (&argc, &argv);
 231   set_program_name (argv[0]);
 232   setlocale (LC_ALL, "");
 233   bindtextdomain (PACKAGE, LOCALEDIR);
 234   textdomain (PACKAGE);
 235
 236   atexit (close_stdout);
 237
 238   while ((optc = getopt_long (argc, argv, short_options, long_options, NULL))
 239          != -1)
 240     switch (optc)
 241       {
 242       case '0': case '1': case '2': case '3': case '4':
 243       case '5': case '6': case '7': case '8': case '9':
 244         if (optind != 2)
 245           {
 246             /* This option is actually a process-id.  */
 247             optind--;
 248             goto no_more_options;
 249           }
 250         /* Fall through.  */
 251       case 'A': case 'B': case 'C': case 'D': case 'E':
 252       case 'F': case 'G': case 'H': case 'I': case 'J':
 253       case 'K': case 'L': case 'M': case 'N': case 'O':
 254       case 'P': case 'Q': case 'R': case 'S': case 'T':
 255       case 'U': case 'V': case 'W': case 'X': case 'Y':
 256       case 'Z':
 257         if (! optarg)
 258           optarg = argv[optind - 1] + strlen (argv[optind - 1]);
 259         if (optarg != argv[optind - 1] + 2)
 260           {
 261             error (0, 0, _("invalid option -- %c"), optc);
 262             usage (EXIT_FAILURE);
 263           }
 264         optarg--;
 265         /* Fall through.  */
 266       case 'n': /* -n is not documented, but is for Bash compatibility.  */
 267       case 's':
 268         if (0 <= signum)
 269           {
 270             error (0, 0, _("%s: multiple signals specified"), optarg);
 271             usage (EXIT_FAILURE);
 272           }
 273         signum = operand2sig (optarg, signame);
 274         if (signum < 0)
 275           usage (EXIT_FAILURE);
 276         break;
 277
 278       case 't':
 279         table = true;
 280         /* Fall through.  */
 281       case 'l':
 282         if (list)
 283           {
 284             error (0, 0, _("multiple -l or -t options specified"));
 285             usage (EXIT_FAILURE);
 286           }
 287         list = true;
 288         break;
 289
 290       case_GETOPT_HELP_CHAR;
 291       case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 292       default:
 293         usage (EXIT_FAILURE);
 294       }
 295  no_more_options:
 296
 297   if (signum < 0)
 298     signum = SIGTERM;
 299   else if (list)
 300     {
 301       error (0, 0, _("cannot combine signal with -l or -t"));
 302       usage (EXIT_FAILURE);
 303     }
 304
 305   if ( ! list && argc <= optind)
 306     {
 307       error (0, 0, _("no process ID specified"));
 308       usage (EXIT_FAILURE);
 309     }
 310
 311   return (list
 312           ? list_signals (table, optind < argc ? argv + optind : NULL)
 313           : send_signals (signum, argv + optind));
 314 }