Adding dialplan function IFMODULE, so you can create dialplans that handle

various PBX installations and checks if a module is loaded before using
it.
	example IFMODULE(chan_sip3.so)

issue #6671 in the bug tracker, finally gone. Thanks to mithraen for keeping
it updated.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@46513 65c4cc65-6c06-0410-ace0-fbb531ad65f3

funcs/func_module.c

@@ -0,0 +1,77 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 1999 - 2006, 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
+ *
+ * \brief Simple module check function
+ * \author Olle E. Johansson, Edvina.net
+ */
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "asterisk/module.h"
+#include "asterisk/channel.h"
+#include "asterisk/pbx.h"
+#include "asterisk/logger.h"
+#include "asterisk/utils.h"
+#include "asterisk/app.h"
+#include "asterisk/module.h"
+
+static int ifmodule_read(struct ast_channel *chan, char *cmd, char *data,
+		    char *buf, size_t len)
+{
+	char *ret = "0";
+
+	*buf = '\0';
+
+	if (data)
+		if (ast_module_check(data))
+			ret = "1";
+
+	ast_copy_string(buf, ret, len);
+
+	return 0;
+}
+
+static struct ast_custom_function ifmodule_function = {
+	.name = "IFMODULE",
+	.synopsis = "Checks if an Asterisk module is loaded in memory",
+	.syntax = "IFMODULE(<modulename.so>)",
+	.read = ifmodule_read,
+	.desc = "Checks if a module is loaded. Use the full module name\n"
+		"as shown by the list in \"show modules\". \n"
+		"Returns \"1\" if module exists in memory, otherwise \"0\".\n",
+};
+
+
+static int unload_module(void)
+{
+	return ast_custom_function_unregister(&ifmodule_function);
+}
+
+static int load_module(void)
+{
+	return ast_custom_function_register(&ifmodule_function);
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Checks if Asterisk module is loaded in memory");

include/asterisk/module.h

@@ -113,6 +113,13 @@ void ast_update_use_count(void);
 int ast_update_module_list(int (*modentry)(const char *module, const char *description, int usecnt, const char *like),
 			   const char *like);
 
+/*!
+ * \brief Check if module with the name given is loaded
+ * \param name Module name, like "chan_sip.so"
+ * \return 0 if false, 1 if true 
+ */
+int ast_module_check(char *name);
+
 /*! 
  * \brief Add a procedure to be run when modules have been updated.
  * \param updater The function to run when modules have been updated.

main/loader.c

@@ -871,6 +871,26 @@ int ast_update_module_list(int (*modentry)(const char *module, const char *descr
 	return total_mod_loaded;
 }
 
+int ast_module_check(char *name)
+{
+	struct ast_module *cur;
+	int unlock = -1;
+	int res = 0;
+
+	if (ast_strlen_zero(name))
+		return 0;       /* FALSE */
+
+	if (ast_mutex_trylock(&module_list.lock))
+		unlock = 0;
+	AST_LIST_TRAVERSE(&module_list, cur, entry)
+	if (!res && !strcasecmp(name, cur->resource))
+		res = 1;
+	if (unlock)
+		AST_LIST_UNLOCK(&module_list);
+	return res;
+}
+
+
 int ast_loader_register(int (*v)(void))
 {
 	struct loadupdate *tmp;