func_shell.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2006-2012, Digium, Inc.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * SHELL function to return the output generated by a command issued to the system shell.
 *
 * \note Inspiration and Guidance from Russell! Thank You!
 *
 * \author Brandon Kruse <bkruse@digium.com>
 *
 * \ingroup functions
 */

/*** MODULEINFO
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/utils.h"
#include "asterisk/app.h"

static int shell_helper(struct ast_channel *chan, const char *cmd, char *data,
		                         char *buf, size_t len)
{
	int res = 0;

	if (ast_strlen_zero(data)) {
		ast_log(LOG_WARNING, "Missing Argument!  Example:  Set(foo=${SHELL(echo \"bar\")})\n");
		return -1;
	}

	if (chan) {
		ast_autoservice_start(chan);
	}

	if (len >= 1) {
		FILE *ptr;
		char plbuff[4096];

		ptr = popen(data, "r");
		if (ptr) {
			while (fgets(plbuff, sizeof(plbuff), ptr)) {
				strncat(buf, plbuff, len - strlen(buf) - 1);
			}
			pclose(ptr);
		} else {
			ast_log(LOG_WARNING, "Failed to execute shell command '%s'\n", data);
			res = -1;
		}
	}