Add a new dialplan function, DIALPLAN_EXISTS(), which allows you to check for

the existence of a dialplan target.

(closes issue #11579)
Reported by: irroot
Patches: 
      func_dialplan2.c uploaded by irroot (license 52)
	  -- Additional changes by me.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@94799 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES

@@ -419,4 +419,5 @@ Miscellaneous
   * A new option when starting a remote asterisk (rasterisk, asterisk -r) for
     specifying which socket to use to connect to the running Asterisk daemon
     (-s)
-
+  * Added a new dialplan function, DIALPLAN_EXISTS(), which allows you to check for
+     the existence of a dialplan target.

funcs/func_dialplan.c

@@ -0,0 +1,106 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2007, 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 Dialplan group functions check if a context exists
+ *
+ * \author Gregory Nietsky AKA irroot <gregory@networksentry.co.za>
+ * \author Russell Bryant <russell@digium.com>
+ * 
+ * \ingroup functions
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/module.h"
+#include "asterisk/channel.h"
+#include "asterisk/pbx.h"
+#include "asterisk/app.h"
+
+static int isexten_function_read(struct ast_channel *chan, const char *cmd, char *data, 
+	char *buf, size_t len) 
+{
+	char *parse;
+	AST_DECLARE_APP_ARGS(args,
+		AST_APP_ARG(context);
+		AST_APP_ARG(exten);
+		AST_APP_ARG(priority);
+	);
+
+	strcpy(buf, "0");
+
+	if (ast_strlen_zero(data)) {
+		ast_log(LOG_ERROR, "DIALPLAN_EXISTS() requires an argument\n");
+		return -1;
+	}
+
+	parse = ast_strdupa(data);
+	AST_STANDARD_APP_ARGS(args, parse);
+
+	if (!ast_strlen_zero(args.priority)) {
+		int priority_num;
+		if (sscanf(args.priority, "%d", &priority_num) == 1 && priority_num > 0) {
+			int res;
+			res = ast_exists_extension(chan, args.context, args.exten, priority_num, 
+				chan->cid.cid_num);
+			if (res)
+				strcpy(buf, "1");
+		} else {
+			int res;
+			res = ast_findlabel_extension(chan, args.context, args.exten, 
+				args.priority, chan->cid.cid_num);
+			if (res > 0)
+				strcpy(buf, "1");
+		}
+	} else if (!ast_strlen_zero(args.exten)) {
+		int res;
+		res = ast_exists_extension(chan, args.context, args.exten, 1, 
+			chan->cid.cid_num);
+		if (res)
+			strcpy(buf, "1");
+	} else if (!ast_strlen_zero(args.context)) {
+		if (ast_context_find(args.context))
+			strcpy(buf, "1");
+	} else {
+		ast_log(LOG_ERROR, "Invalid arguments provided to DIALPLAN_EXISTS\n");
+		return -1;
+	}
+	
+	return 0;
+}
+
+static struct ast_custom_function isexten_function = {
+	.name = "DIALPLAN_EXISTS",
+	.syntax = "DIALPLAN_EXISTS(context[,extension[,priority]])",
+	.synopsis = "Checks the existence of a dialplan target.",
+	.desc = "This function returns 1 if the target exits.  Otherwise, it returns 0.\n",
+	.read = isexten_function_read,
+};
+
+static int unload_module(void)
+{
+	return ast_custom_function_unregister(&isexten_function);
+}
+
+static int load_module(void)
+{
+	return ast_custom_function_register(&isexten_function);
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Dialplan Context/Extension/Priority Checking Functions");