--- funcs/func_strings.c.orig	2005-06-04 11:44:49.000000000 +0200
+++ funcs/func_strings.c	2005-06-04 11:44:00.000000000 +0200
@@ -203,3 +203,45 @@
 	.read = function_eval,
 };
 
+static char *function_strstr(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len) 
+{
+	char *args = ast_strdupa(data);
+	char *argv[2],*strpos;
+	int argc,position;
+
+	if (!data || ast_strlen_zero(data)) {
+		ast_log(LOG_WARNING, "STRSTR requires an argument: STRSTR(<needle>,<haystack>)\n");
+		return buf;
+	}
+
+	argc = ast_separate_app_args(args, '|', argv, sizeof(argv) / sizeof(argv[0]));
+	if (argc > 1) {
+		strpos = strstr(argv[1],argv[0]);
+		if (strpos) {
+			position = strpos - argv[1];
+			sprintf(buf,"%i",position);
+		} else {
+			strcpy(buf,"-1");
+		}
+		return buf;
+	} else {
+		ast_log(LOG_WARNING, "STRSTR requires an argument: STRSTR(<needle>,<haystack>)\n");
+		return buf;
+	}
+	return buf;
+}
+
+#ifndef BUILTIN_FUNC
+static
+#endif
+struct ast_custom_function strstr_function = {
+	.name = "STRSTR",
+	.synopsis = "Determines The Position In A Substr In A String.",
+	.syntax = "STRSTR(<needle>,<haystack>)",
+	.desc = "This function will look in the supplied string haystack\n"
+		"for the substring needle returning the position.\n"
+		"Returns the position of the substring or -1 if not found.\n",
+	.read = function_strstr,
+};
+
+