PHP Manual . ... Next . PHP 4 >= 4.0.0) strncmp -- Binary safe string comparison of the first n characters . int strncmp ( string str1, string str2, int len) . This function is similar to strcmp() , with the difference that you can specify the (upper limit of the) number of characters ( len ) from each string to be used in the comparison. If any of the strings is shorter than len , then the length of that string will be used for the comparison. ...