source: vendor/bash/3.1/builtins/kill.def

This file is kill.def, from which is created kill.c.
It implements the builtin "kill" in Bash.

Copyright (C) 1987-2005 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

Bash is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

Bash is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with Bash; see the file COPYING.  If not, write to the Free Software
Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.

$PRODUCES kill.c

$BUILTIN kill
$FUNCTION kill_builtin
$SHORT_DOC kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... or kill -l [sigspec]
Send the processes named by PID (or JOBSPEC) the signal SIGSPEC.  If
SIGSPEC is not present, then SIGTERM is assumed.  An argument of `-l'
lists the signal names; if arguments follow `-l' they are assumed to
be signal numbers for which names should be listed.  Kill is a shell
builtin for two reasons: it allows job IDs to be used instead of
process IDs, and, if you have reached the limit on processes that
you can create, you don't have to start a process to kill another one.
$END

#include <config.h>

#include <stdio.h>
#include <errno.h>
#if defined (HAVE_UNISTD_H)
#  ifdef _MINIX
#    include <sys/types.h>
#  endif
#  include <unistd.h>
#endif

#include "../bashansi.h"
#include "../bashintl.h"

#include "../shell.h"
#include "../trap.h"
#include "../jobs.h"
#include "common.h"

/* Not all systems declare ERRNO in errno.h... and some systems #define it! */
#if !defined (errno)
extern int errno;
#endif /* !errno */

extern int posixly_correct;

static void kill_error __P((pid_t, int));

#if !defined (CONTINUE_AFTER_KILL_ERROR)
#  define CONTINUE_OR_FAIL return (EXECUTION_FAILURE)
#else
#  define CONTINUE_OR_FAIL goto continue_killing
#endif /* CONTINUE_AFTER_KILL_ERROR */

/* Here is the kill builtin.  We only have it so that people can type
   kill -KILL %1?  No, if you fill up the process table this way you
   can still kill some. */
int
kill_builtin (list)
     WORD_LIST *list;
{
  int sig, any_succeeded, listing, saw_signal, dflags;
  char *sigspec, *word;
  pid_t pid;
  intmax_t pid_value;

  if (list == 0)
    {
      builtin_usage ();
      return (EXECUTION_FAILURE);
    }

  any_succeeded = listing = saw_signal = 0;
  sig = SIGTERM;
  sigspec = "TERM";

  dflags = DSIG_NOCASE | ((posixly_correct == 0) ? DSIG_SIGPREFIX : 0);
  /* Process options. */
  while (list)
    {
      word = list->word->word;

      if (ISOPTION (word, 'l'))
        {
          listing++;
          list = list->next;
        }
      else if (ISOPTION (word, 's') || ISOPTION (word, 'n'))
        {
          list = list->next;
          if (list)
            {
              sigspec = list->word->word;
              if (sigspec[0] == '0' && sigspec[1] == '\0')
                sig = 0;
              else
                sig = decode_signal (sigspec, dflags);
              list = list->next;
            }
          else
            {
              sh_needarg (word);
              return (EXECUTION_FAILURE);
            }
        }
      else if (ISOPTION (word, '-'))
        {
          list = list->next;
          break;
        }
      else if (ISOPTION (word, '?'))
        {
          builtin_usage ();
          return (EXECUTION_SUCCESS);
        }
      /* If this is a signal specification then process it.  We only process
         the first one seen; other arguments may signify process groups (e.g,
         -num == process group num). */
      else if ((*word == '-') && !saw_signal)
        {
          sigspec = word + 1;
          sig = decode_signal (sigspec, dflags);
          saw_signal++;
          list = list->next;
        }
      else
        break;
    }

  if (listing)
    return (display_signal_list (list, 0));

  /* OK, we are killing processes. */
  if (sig == NO_SIG)
    {
      sh_invalidsig (sigspec);
      return (EXECUTION_FAILURE);
    }

  if (list == 0)
    {
      builtin_usage ();
      return (EXECUTION_FAILURE);
    }

  while (list)
    {
      word = list->word->word;

      if (*word == '-')
        word++;

      /* Use the entire argument in case of minus sign presence. */
      if (*word && legal_number (list->word->word, &pid_value) && (pid_value == (pid_t)pid_value))
        {
          pid = (pid_t) pid_value;

          if (kill_pid (pid, sig, pid < -1) < 0)
            {
              if (errno == EINVAL)
                sh_invalidsig (sigspec);
              else
                kill_error (pid, errno);
              CONTINUE_OR_FAIL;
            }
          else
            any_succeeded++;
        }
#if defined (JOB_CONTROL)
      else if (*list->word->word && *list->word->word != '%')
        {
          builtin_error (_("%s: arguments must be process or job IDs"), list->word->word);
          CONTINUE_OR_FAIL;
        }
      else if (*word)
        /* Posix.2 says you can kill without job control active (4.32.4) */
        {                       /* Must be a job spec.  Check it out. */
          int job;
          sigset_t set, oset;
          JOB *j;

          BLOCK_CHILD (set, oset);
          job = get_job_spec (list);

          if (INVALID_JOB (job))
            {
              if (job != DUP_JOB)
                sh_badjob (list->word->word);
              UNBLOCK_CHILD (oset);
              CONTINUE_OR_FAIL;
            }

          j = get_job_by_jid (job);
          /* Job spec used.  Kill the process group. If the job was started
             without job control, then its pgrp == shell_pgrp, so we have
             to be careful.  We take the pid of the first job in the pipeline
             in that case. */
          pid = IS_JOBCONTROL (job) ? j->pgrp : j->pipe->pid;

          UNBLOCK_CHILD (oset);

          if (kill_pid (pid, sig, 1) < 0)
            {
              if (errno == EINVAL)
                sh_invalidsig (sigspec);
              else
                kill_error (pid, errno);
              CONTINUE_OR_FAIL;
            }
          else
            any_succeeded++;
        }
#endif /* !JOB_CONTROL */
      else
        {
          sh_badpid (list->word->word);
          CONTINUE_OR_FAIL;
        }
    continue_killing:
      list = list->next;
    }

  return (any_succeeded ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
}

static void
kill_error (pid, e)
     pid_t pid;
     int e;
{
  char *x;

  x = strerror (e);
  if (x == 0)
    x = _("Unknown error");
  builtin_error ("(%ld) - %s", (long)pid, x);
}