/* Subprocesses with pipes.
Copyright (C) 2005, 2006 Free Software Foundation, Inc.
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. */
/* Written by Juan Manuel Guerrero <juan.guerrero@gmx.de>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "subpipe.h"
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <process.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "xalloc.h"
#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#include "error.h"
#include "gettext.h"
#define _(Msgid) gettext (Msgid)
/* Initialize this module. */
static int old_stdin;
static int old_stdout;
static char **arguments;
static char tmp_file_name[2][L_tmpnam];
#define remove_tmp_file(fd, name) \
do { \
close ((fd)); \
if (unlink ((name))) \
error (EXIT_FAILURE, 0, _("removing of `%s' failed"), (name)); \
} while (0)
void
init_subpipe(void)
{
int fd;
strcpy(tmp_file_name[0], "/dev/env/TMPDIR/bnXXXXXX");
fd = mkstemp(tmp_file_name[0]);
if (fd < 0)
error(EXIT_FAILURE, 0, _("creation of a temporary file failed"));
close (fd);
strcpy(tmp_file_name[1], "/dev/env/TMPDIR/bnXXXXXX");
fd = mkstemp(tmp_file_name[1]);
if (fd < 0)
error(EXIT_FAILURE, 0, _("creation of a temporary file failed"));
close (fd);
}
/* Create a subprocess that is run as a filter. ARGV is the
NULL-terminated argument vector for the subprocess. Store read and
write file descriptors for communication with the subprocess into
FD[0] and FD[1]: input meant for the process can be written into
FD[0], and output from the process can be read from FD[1]. Return
the subprocess id.
Because DOS has neither fork nor pipe functionality to run the subprocess
as a filter, the filter is reproduced using temporary files. First bison's
stdout is redirected to a temporary file. After bison has produced all of
is output, this file is closed and connected to m4's stdin. All m4's output
is redirected from m4's stdout to a second temporary file and reopened as
bison's stdin. */
pid_t
create_subpipe(char const *const *argv, int fd[2])
{
int argc;
int from_in_fd; /* pipe from bison to m4. */
pid_t pid;
pid = getpid();
/*
* Save original stdin and stdout
* for later restauration.
*/
old_stdin = dup(STDIN_FILENO);
if (old_stdin < 0)
error(EXIT_FAILURE, 0, _("saving stdin failed"));
old_stdout = dup(STDOUT_FILENO);
if (old_stdout < 0)
error(EXIT_FAILURE, 0, _("saving stdout failed"));
/*
* Save argv for later use.
*/
for (argc = 0; argv[argc]; argc++)
;
argc++;
arguments = xmalloc(argc * sizeof(arguments[0]));
for (argc = 0; argv[argc]; argc++)
{
arguments[argc] = xmalloc((strlen(argv[argc]) + 1) * sizeof(arguments[0][0]));
strcpy(arguments[argc], argv[argc]);
}
arguments[argc] = NULL;
/*
* All bison's output will be gathered in this temporary file
* and will be redirected to m4's stdin.
*/
from_in_fd = open(tmp_file_name[0], O_WRONLY | O_CREAT | O_TRUNC, S_IWUSR);
if (from_in_fd < 0)
error(EXIT_FAILURE, 0, _("opening of tmpfile failed"));
if (dup2(from_in_fd, STDOUT_FILENO) < 0)
{
remove_tmp_file(from_in_fd, tmp_file_name[0]);
error(EXIT_FAILURE, 0, _("redirecting bison's stdout to the temporary file failed"));
}
close(from_in_fd);
fd[0] = STDOUT_FILENO;
return pid;
}
/* A signal handler that just records that a signal has happened. */
static int child_interrupted;
static void
signal_catcher(int signo)
{
child_interrupted++;
}
void
end_of_output_subpipe(pid_t pid, int fd[2])
{
char *program;
int from_out_fd = open(tmp_file_name[0], O_RDONLY, S_IRUSR); /* pipe from bison to m4. */
int to_in_fd = open(tmp_file_name[1], O_WRONLY | O_CREAT | O_TRUNC, S_IWUSR); /* pipe from m4 to bison. */
int status;
void (*previous_handler)(int);
program = strrchr(arguments[0], '/');
if (program)
program++;
else
program = arguments[0];
/*
* Redirect bison's output to m4's stdin.
*/
if (from_out_fd < 0)
error(EXIT_FAILURE, 0, _("opening of tmpfile failed"));
if (dup2(from_out_fd, STDIN_FILENO) < 0)
{
remove_tmp_file(from_out_fd, tmp_file_name[0]);
error(EXIT_FAILURE, 0, _("redirecting m4's stdin from the temporary file failed"));
}
close(from_out_fd);
/*
* All m4's output will be gathered in this temporary file
* and will be redirected to bison's stdin.
*/
if (to_in_fd < 0)
{
remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
error(EXIT_FAILURE, 0, _("opening of a temporary file failed"));
}
if (dup2(to_in_fd, STDOUT_FILENO) < 0)
{
remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
remove_tmp_file(to_in_fd, tmp_file_name[1]);
error(EXIT_FAILURE, 0, _("redirecting m4's stdout to a temporary file failed"));
}
close(to_in_fd);
/*
* Run m4.
*/
child_interrupted = 0;
errno = 0;
previous_handler = signal(SIGINT, signal_catcher);
status = spawnvp(P_WAIT, program, arguments);
signal(SIGINT, previous_handler);
if (child_interrupted)
{
remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
remove_tmp_file(STDOUT_FILENO, tmp_file_name[1]);
error(EXIT_FAILURE, 0, _("subsidiary program `%s' interrupted"), program);
}
if (status)
{
remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
remove_tmp_file(STDOUT_FILENO, tmp_file_name[1]);
error(EXIT_FAILURE, 0, _(errno == ENOENT
? "subsidiary program `%s' not found"
: status < 1
? "subsidiary program `%s' failed"
: "subsidiary program `%s' failed (status=%i, errno=%i)"), program, status, errno);
}
/*
* Redirect m4's output to bison's stdin.
*/
if (dup2(old_stdout, STDOUT_FILENO) < 0)
error(EXIT_FAILURE, 0, "restore of bison's stdout failed");
close(old_stdout);
to_in_fd = open(tmp_file_name[1], O_RDONLY, S_IRUSR); /* pipe from m4 to bison. */
if (to_in_fd < 0)
{
remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
error(EXIT_FAILURE, 0, _("opening of tmpfile failed"));
}
if (dup2(to_in_fd, STDIN_FILENO) < 0)
{
remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
remove_tmp_file(to_in_fd, tmp_file_name[1]);
error(EXIT_FAILURE, -1, "dup2");
error(EXIT_FAILURE, 0, _("redirecting bison's stdin from the temporary file failed"));
}
close(to_in_fd);
fd[1] = STDIN_FILENO;
}
/* Free resources, unlink temporary files and restore stdin and stdout. */
void
reap_subpipe(pid_t pid, char const *program)
{
int argc;
for (argc = 0; arguments[argc]; argc++)
free(arguments[argc]);
free(arguments);
if (unlink(tmp_file_name[0]))
error(EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[0]);
if (unlink(tmp_file_name[1]))
error(EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[1]);
if (dup2(old_stdin, STDIN_FILENO) < 0)
error(EXIT_FAILURE, 0, "restore of bison's stdin failed");
close(old_stdin);
}