Asterisk's simplest module

res_hello.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2012, Digium, Inc.
 *
 * David M. Lee, II <dlee@digium.com>
 *
 * 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
 *
 * \brief Hello - Asterisk's simplest module.
 *
 * \author David M. Lee, II <dlee@digium.com>
 */

#include "asterisk.h"
#include "asterisk/module.h"

/*
 * MODULEINFO block contains module metadata (support level, dependencies, etc.)
 */

/*** MODULEINFO
        <support_level>extended</support_level>
	<defaulteanbled>no</defaulteanbled>
 ***/

/*!
 * \brief Load the res_hello.so module.
 *
 * There's no way for this module to fail to load, so it always returns
 * AST_MODULE_LOAD_SUCCESS.
 */
static int load_module(void)
{
    ast_log(AST_LOG_NOTICE, "Hello, Asterisk");
    /* AST_MODULE_LOAD_FAILURE would indicate a fatal error, such as a missing
     * dependency.
     */

    /* AST_MODULE_LOAD_DECLINE would indicate failure to load due to bad
     * or missing configuration.
     */
    return AST_MODULE_LOAD_SUCCESS;
}

/*!
 * /brief Unloaad the res_hello.so module.
 *
 * Like loading, this is too simple to fail.
 */
static int unload_module(void)
{
    ast_log(AST_LOG_NOTICE, "Goodbye, Asterisk\n");
    /* If modules resources are still in use, or cannot be unloaded, return -1 */
    return 0;
}

/* The following module information blob has the necessary module metadata to make the module
 * usable by Asterisk. AST_MODULE_INFO allows more options to be set, but they're usually not
 * necessary.
 */
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Hello, Asterisk!");