Returns a portion of a the string **s**, specified by the **offset** and **length** parameters. The string porttion is copied into the string **dest**, up to a limit of **max_len** characters. If there is not enough room, **NULL** is returned.
+
Returns a portion of a the string ***s***, specified by the **offset** and **length** parameters. The string porttion is copied into the string **dest**, up to a limit of **max_len** characters. If there is not enough room, **NULL** is returned.