Email+URL的判断和自动转换函数

<?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 = eregireplace("((ht|f)tp://www\.|www\.)([a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})((/|\?)[a-z0-9~#%&\\/'\+=:\?\.-]))", "http://www.\\3", $text);
$text = eregireplace("((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", $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}))", "\\0", $text);
return $text;
}

function convertAllLinks($text)
{ $text = convertURLS($text);
$text = convertMail($text);
return $text;
}
?>