Add function to the String API for locating the last instance of a substring in a string.

git-svn-id: http://yate.null.ro/svn/yate/trunk@5916 acf43c95-373e-0410-b603-e72c3f656dc1

engine/String.cpp

@@ -1050,6 +1050,14 @@ int String::rfind(char what) const
     return s ? s-m_string : -1;
 }
 
+int String::rfind(const char* what) const
+{
+    int ret = -1;
+    for (int pos = -1; (pos = find(what,pos + 1)) >= 0;)
+	ret = pos;
+    return ret;
+}
+
 bool String::startsWith(const char* what, bool wordBreak, bool caseInsensitive) const
 {
     if (!(m_string && what && *what))

yateclass.h

@@ -2445,6 +2445,13 @@ public:
      */
     int rfind(char what) const;
 
+    /**
+     * Locate the last instance of a substring in the string
+     * @param what Substring to search for
+     * @return Offset of substring or -1 if not found
+     */
+    int rfind(const char* what) const;
+
     /**
      * Checks if the string starts with a substring
      * @param what Substring to search for