<?php
function validateEmail($email)
{ return eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email);
}
function validateURL($url)
{ return eregi("^((ht|f)tp://)((([a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3}))|(([0-9]{1,3}\.){3}([0-9]{1,3})))((/|\?)[a-z0-9~#%&‘_\+=:\?\.-]*)*)$", $url);
}
function convertURLS($text)
{ $text = eregi_replace("((ht|f)tp://www\.|www\.)([a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})((/|\?)[a-z0-9~#%&\\/‘_\+=:\?\.-]*)*)", "http://www.\\3", $text);
$text = eregi_replace("((ht|f)tp://)((([a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3}))|(([0-9]{1,3}\.){3}([0-9]{1,3})))((/|\?)[a-z0-9~#%&‘_\+=:\?\.-]*)*)", "<a href=\"\\0\">\\0</a>", $text);
return $text;
}
function convertMail($text)
{ $text = eregi_replace("([_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3}))", "<a href=‘mailto:\\0‘>\\0</a>", $text);
return $text;
}
function convertAllLinks($text)
{ $text = convertURLS($text);
$text = convertMail($text);
return $text;
}
?> Email+URL的判断和自动转换函数
原文：http://www.jb51.net/article/2012.htm
