Description
string 
str_rot13 ( string str)
     This function performs the ROT13 encoding on the
     str argument and returns the resulting
     string. The ROT13 encoding simply shifts every letter by 13
     places in the alphabet while leaving non-alpha characters
     untouched. Encoding and decoding are done by the same function,
     passing an encoded string as argument will return the original version.
    
     
| 例子 1. str_rot13() example | 
<?php
 echo str_rot13('PHP 4.3.0'); // CUC 4.3.0
 
 ?>
 | 
 | 
    注: 
      The behaviour of this function was buggy until PHP 4.3.0. Before
      this, the str was also modified, as if
      passed by reference.