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/* Creation of autonomous subprocesses.
Copyright (C) 2001 Free Software Foundation, Inc.
Written by Bruno Haible <haible@clisp.cons.org>, 2001.
This program 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.
This program 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 this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
/* Specification. */
#include "execute.h"
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_POSIX_SPAWN
# include <spawn.h>
#else
# ifdef HAVE_VFORK_H
# include <vfork.h>
# endif
#endif
#include "error.h"
#include "wait-process.h"
#include "libgettext.h"
#ifndef EXIT_FAILURE
# define EXIT_FAILURE 1
#endif
#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
# define STDERR_FILENO 2
#endif
#define _(str) gettext (str)
/* Prototypes for local functions. Needed to ensure compiler checking of
function argument counts despite of K&R C function definition syntax. */
#ifdef EINTR
static inline int nonintr_close PARAMS ((int fd));
static inline int nonintr_open PARAMS ((const char *pathname, int oflag,
mode_t mode));
#endif
#ifdef EINTR
/* EINTR handling for close(), open().
These functions can return -1/EINTR even though we don't have any
signal handlers set up, namely when we get interrupted via SIGSTOP. */
static inline int
nonintr_close (fd)
int fd;
{
int retval;
do
retval = close (fd);
while (retval < 0 && errno == EINTR);
return retval;
}
#define close nonintr_close
static inline int
nonintr_open (pathname, oflag, mode)
const char *pathname;
int oflag;
mode_t mode;
{
int retval;
do
retval = open (pathname, oflag, mode);
while (retval < 0 && errno == EINTR);
return retval;
}
#define open nonintr_open
#endif
/* Execute a command, optionally redirecting any of the three standard file
descriptors to /dev/null. Return its exit code.
If it didn't terminate correctly, exit if exit_on_error is true, otherwise
return 127. */
int
execute (progname, prog_path, prog_argv, null_stdin, null_stdout, null_stderr, exit_on_error)
const char *progname;
const char *prog_path;
char **prog_argv;
bool null_stdin;
bool null_stdout;
bool null_stderr;
bool exit_on_error;
{
/* Note about 127: Some errors during posix_spawnp() cause the function
posix_spawnp() to return an error code; some other errors cause the
subprocess to exit with return code 127. It is implementation
dependent which error is reported which way. We treat both cases as
equivalent. */
#if HAVE_POSIX_SPAWN
posix_spawn_file_actions_t actions;
bool actions_allocated;
int err;
pid_t child;
#else
int child;
#endif
#if HAVE_POSIX_SPAWN
actions_allocated = false;
if ((err = posix_spawn_file_actions_init (&actions)) != 0
|| (actions_allocated = true,
(null_stdin
&& (err = posix_spawn_file_actions_addopen (&actions,
STDIN_FILENO,
"/dev/null", O_RDONLY,
0))
!= 0)
|| (null_stdout
&& (err = posix_spawn_file_actions_addopen (&actions,
STDOUT_FILENO,
"/dev/null", O_RDWR,
0))
!= 0)
|| (null_stderr
&& (err = posix_spawn_file_actions_addopen (&actions,
STDERR_FILENO,
"/dev/null", O_RDWR,
0))
!= 0)
|| (err = posix_spawnp (&child, prog_path, &actions, NULL, prog_argv,
environ))
!= 0))
{
if (actions_allocated)
posix_spawn_file_actions_destroy (&actions);
if (exit_on_error)
error (EXIT_FAILURE, err, _("%s subprocess failed"), progname);
else
return 127;
}
posix_spawn_file_actions_destroy (&actions);
#else
/* Use vfork() instead of fork() for efficiency. */
if ((child = vfork ()) == 0)
{
/* Child process code. */
int nullinfd;
int nulloutfd;
if ((!null_stdin
|| ((nullinfd = open ("/dev/null", O_RDONLY, 0)) >= 0
&& (nullinfd == STDIN_FILENO
|| (dup2 (nullinfd, STDIN_FILENO) >= 0
&& close (nullinfd) >= 0))))
&& (!(null_stdout || null_stderr)
|| ((nulloutfd = open ("/dev/null", O_RDWR, 0)) >= 0
&& (!null_stdout
|| nulloutfd == STDOUT_FILENO
|| dup2 (nulloutfd, STDOUT_FILENO) >= 0)
&& (!null_stderr
|| nulloutfd == STDERR_FILENO
|| dup2 (nulloutfd, STDERR_FILENO) >= 0)
&& ((null_stdout && nulloutfd == STDOUT_FILENO)
|| (null_stderr && nulloutfd == STDERR_FILENO)
|| close (nulloutfd) >= 0))))
execvp (prog_path, prog_argv);
_exit (-1);
}
if (child == -1)
{
if (exit_on_error)
error (EXIT_FAILURE, errno, _("%s subprocess failed"), progname);
else
return 127;
}
#endif
return wait_subprocess (child, progname, exit_on_error);
}
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