/* Creation of autonomous subprocesses.
Copyright (C) 2001-2004, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <config.h>
/* Specification. */
#include "execute.h"
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include "error.h"
#include "exit.h"
#include "fatal-signal.h"
#include "wait-process.h"
#include "gettext.h"
#define _(str) gettext (str)
#if defined _MSC_VER || defined __MINGW32__
/* Native Woe32 API. */
# include <process.h>
# include "w32spawn.h"
#else
/* Unix API. */
# ifdef HAVE_POSIX_SPAWN
# include <spawn.h>
# else
# ifdef HAVE_VFORK_H
# include <vfork.h>
# endif
# endif
#endif
#ifndef HAVE_ENVIRON_DECL
extern char **environ;
#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
#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 (int fd)
{
int retval;
do
retval = close (fd);
while (retval < 0 && errno == EINTR);
return retval;
}
#define close nonintr_close
static inline int
nonintr_open (const char *pathname, int oflag, mode_t mode)
{
int retval;
do
retval = open (pathname, oflag, mode);
while (retval < 0 && errno == EINTR);
return retval;
}
#undef open /* avoid warning on VMS */
#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.
If slave_process is true, the child process will be terminated when its
creator receives a catchable fatal signal. */
int
execute (const char *progname,
const char *prog_path, char **prog_argv,
bool ignore_sigpipe,
bool null_stdin, bool null_stdout, bool null_stderr,
bool slave_process, bool exit_on_error)
{
#if defined _MSC_VER || defined __MINGW32__
/* Native Woe32 API. */
int orig_stdin;
int orig_stdout;
int orig_stderr;
int exitcode;
int nullinfd;
int nulloutfd;
prog_argv = prepare_spawn (prog_argv);
/* Save standard file handles of parent process. */
if (null_stdin)
orig_stdin = dup_noinherit (STDIN_FILENO);
if (null_stdout)
orig_stdout = dup_noinherit (STDOUT_FILENO);
if (null_stderr)
orig_stderr = dup_noinherit (STDERR_FILENO);
exitcode = -1;
/* Create standard file handles of child process. */
nullinfd = -1;
nulloutfd = -1;
if ((!null_stdin
|| ((nullinfd = open ("NUL", O_RDONLY, 0)) >= 0
&& (nullinfd == STDIN_FILENO
|| (dup2 (nullinfd, STDIN_FILENO) >= 0
&& close (nullinfd) >= 0))))
&& (!(null_stdout || null_stderr)
|| ((nulloutfd = open ("NUL", 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))))
exitcode = spawnvp (P_WAIT, prog_path, prog_argv);
if (nulloutfd >= 0)
close (nulloutfd);
if (nullinfd >= 0)
close (nullinfd);
/* Restore standard file handles of parent process. */
if (null_stderr)
dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
if (null_stdout)
dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
if (null_stdin)
dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
if (exitcode == -1)
{
if (exit_on_error || !null_stderr)
error (exit_on_error ? EXIT_FAILURE : 0, errno,
_("%s subprocess failed"), progname);
return 127;
}
return exitcode;
#else
/* Unix API. */
/* 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
sigset_t blocked_signals;
posix_spawn_file_actions_t actions;
bool actions_allocated;
posix_spawnattr_t attrs;
bool attrs_allocated;
int err;
pid_t child;
#else
int child;
#endif
#if HAVE_POSIX_SPAWN
if (slave_process)
{
sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
block_fatal_signals ();
}
actions_allocated = false;
attrs_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)
|| (slave_process
&& ((err = posix_spawnattr_init (&attrs)) != 0
|| (attrs_allocated = true,
(err = posix_spawnattr_setsigmask (&attrs,
&blocked_signals))
!= 0
|| (err = posix_spawnattr_setflags (&attrs,
POSIX_SPAWN_SETSIGMASK))
!= 0)))
|| (err = posix_spawnp (&child, prog_path, &actions,
attrs_allocated ? &attrs : NULL, prog_argv,
environ))
!= 0))
{
if (actions_allocated)
posix_spawn_file_actions_destroy (&actions);
if (attrs_allocated)
posix_spawnattr_destroy (&attrs);
if (slave_process)
unblock_fatal_signals ();
if (exit_on_error || !null_stderr)
error (exit_on_error ? EXIT_FAILURE : 0, err,
_("%s subprocess failed"), progname);
return 127;
}
posix_spawn_file_actions_destroy (&actions);
if (attrs_allocated)
posix_spawnattr_destroy (&attrs);
#else
if (slave_process)
block_fatal_signals ();
/* 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)))
&& (!slave_process || (unblock_fatal_signals (), true)))
execvp (prog_path, prog_argv);
_exit (127);
}
if (child == -1)
{
if (slave_process)
unblock_fatal_signals ();
if (exit_on_error || !null_stderr)
error (exit_on_error ? EXIT_FAILURE : 0, errno,
_("%s subprocess failed"), progname);
return 127;
}
#endif
if (slave_process)
{
register_slave_subprocess (child);
unblock_fatal_signals ();
}
return wait_subprocess (child, progname, ignore_sigpipe, null_stderr,
slave_process, exit_on_error);
#endif
}