/*

 * fork.c - Provide fork and waitpid functions for gawk.

 *

 * Revised 6/2004

 * Revised 5/2012 for new extension API.

 */

/*

 * Copyright (C) 2001, 2004, 2011, 2012, 2013 the Free Software Foundation, Inc.

 *

 * This file is part of GAWK, the GNU implementation of the

 * AWK Programming Language.

 *

 * GAWK 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 3 of the License, or

 * (at your option) any later version.

 *

 * GAWK 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

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdio.h>

#include <assert.h>

#include <errno.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/wait.h>

#include <sys/types.h>

#include <sys/stat.h>

#include "gawkapi.h"

#include "gettext.h"

#define _(msgid)  gettext(msgid)

#define N_(msgid) msgid

static const gawk_api_t *api;	/* for convenience macros to work */

static awk_ext_id_t ext_id;

static const char *ext_version = "fork extension: version 1.0";

static awk_bool_t (*init_func)(void) = NULL;

int plugin_is_GPL_compatible;

/* array_set --- set an array element */

static void

array_set_numeric(awk_array_t array, const char *sub, double num)

{

	awk_value_t index, value;

	set_array_element(array,

		make_const_string(sub, strlen(sub), & index),

		make_number(num, & value));

}

/*  do_fork --- provide dynamically loaded fork() builtin for gawk */

static awk_value_t *

do_fork(int nargs, awk_value_t *result, struct awk_ext_func *unused)

{

	int ret = -1;

	assert(result != NULL);

	ret = fork();

	if (ret < 0)

		update_ERRNO_int(errno);

	else if (ret == 0) {

		/* update PROCINFO in the child, if the array exists */

		awk_value_t procinfo;

		if (sym_lookup("PROCINFO", AWK_ARRAY, & procinfo)) {

			if (procinfo.val_type != AWK_ARRAY) {

				if (do_lint)

					lintwarn(ext_id, _("fork: PROCINFO is not an array!"));

			} else {

				array_set_numeric(procinfo.array_cookie, "pid", getpid());

				array_set_numeric(procinfo.array_cookie, "ppid", getppid());

			}

		}

	}

	/* Set the return value */

	return make_number(ret, result);

}

/*  do_waitpid --- provide dynamically loaded waitpid() builtin for gawk */

static awk_value_t *

do_waitpid(int nargs, awk_value_t *result, struct awk_ext_func *unused)

{

	awk_value_t pid;

	int ret = -1;

	int options = 0;

	assert(result != NULL);

	if (get_argument(0, AWK_NUMBER, &pid)) {

		options = WNOHANG|WUNTRACED;

		ret = waitpid(pid.num_value, NULL, options);

		if (ret < 0)

			update_ERRNO_int(errno);

	}

	/* Set the return value */

	return make_number(ret, result);

}

/*  do_wait --- provide dynamically loaded wait() builtin for gawk */

static awk_value_t *

do_wait(int nargs, awk_value_t *result, struct awk_ext_func *unused)

{

	int ret;

	assert(result != NULL);

	ret = wait(NULL);

	if (ret < 0)

		update_ERRNO_int(errno);

	/* Set the return value */

	return make_number(ret, result);

}

static awk_ext_func_t func_table[] = {

	{ "fork", do_fork, 0, 0, awk_false, NULL },

	{ "waitpid", do_waitpid, 1, 1, awk_false, NULL },

	{ "wait", do_wait, 0, 0, awk_false, NULL },

};

/* define the dl_load function using the boilerplate macro */

dl_load_func(func_table, fork, "")