As per bug 8859 (Add option to revert old ChanIsAvail() with 's' option behavior), this update makes the 't' option available, which calls ast_parse_device_state instead of ast_device_state. This option will not dive into the channel driver to find the status of the device (which could be good if sip devicestate isn't returning full status, for various reasons).

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@52086 65c4cc65-6c06-0410-ace0-fbb531ad65f3

UPGRADE.txt

@@ -31,3 +31,6 @@ Applications:
   to make them more distinguishable from 'maxmsgs', which sets folder
   size.  The old variables will continue to work in this version, albeit
   with a deprecation warning.
+* ChanIsAvail() now has a 't' option, which allows the specified device
+  to be queried for state without consulting the channel drivers. This
+  performs mostly a 'ChanExists' sort of function.

apps/app_chanisavail.c

@@ -61,12 +61,14 @@ static char *descrip =
 "  ${AVAILSTATUS}   - the status code for the available channel\n"
 "  Options:\n"
 "    s - Consider the channel unavailable if the channel is in use at all\n"
+"    t - Simply checks if specified channels exist in the channel list\n"
+"        (implies option s) \n"
 "    j - Support jumping to priority n+101 if no channel is available\n";
 
 
 static int chanavail_exec(struct ast_channel *chan, void *data)
 {
-	int res=-1, inuse=-1, option_state=0, priority_jump=0;
+	int res=-1, inuse=-1, option_state=0, priority_jump=0, string_compare=0;
 	int status;
 	struct ast_module_user *u;
 	char *info, tmp[512], trychan[512], *peers, *tech, *number, *rest, *cur;
@@ -90,6 +92,8 @@ static int chanavail_exec(struct ast_channel *chan, void *data)
 	if (args.options) {
 		if (strchr(args.options, 's'))
 			option_state = 1;
+		if (strchr(args.options, 't'))
+			string_compare = 1;
 		if (strchr(args.options, 'j'))
 			priority_jump = 1;
 	}
@@ -113,7 +117,13 @@ static int chanavail_exec(struct ast_channel *chan, void *data)
 			*number = '\0';
 			number++;
 			
-			if (option_state) {
+			if (string_compare) {
+				/* ast_parse_device_state checks for "SIP/1234" as a channel name. 
+				   ast_device_state will ask the SIP driver for the channel state. */
+
+				snprintf(trychan, sizeof(trychan), "%s/%s",cur,number);
+				status = inuse = ast_parse_device_state(trychan);
+			} else if (option_state) {
 				/* If the pbx says in use then don't bother trying further.
 				   This is to permit testing if someone's on a call, even if the 
 	 			   channel can permit more calls (ie callwaiting, sip calls, etc).  */