【www.gdgbn.com--正则表达式】

//方法一

$ereg_str[url] =   "^[hh]{1}[tt]{2}[pp]{1}://[ww]{3}.[0-9a-za-z][0-9a-za-z-]{0,25}((.[a-za-z]{3,4})|(.[a-za-z]{2})){1,2}$ ";　//判断一个合法的url
$pattern =   $ereg_str["url"];
if(ereg($pattern,$string)) echo   "
right! ";
else   echo   "
error! ";
}

//

$str[]   =   "http://www.111cn.net";

$pattern   =   "/^(http://)?www.[0-9a-z][0-9a-z-]{0,25}((.(aero|biz|cc|co|com|coop|edu|gov|info|int|mil|museum|name|nato|net|org|tv))?(.(af|aq|at|au|be|bg|br|ca|ch|cl|cn|de|eg|es|fi|fr|gr|hk|hu|ie|il|in|iq|ir|is|it|jp|kr|mx|nl|no|nz|pe|ph|pr|pt|ru|se|sg|th|tr|tw|uk|us|za))?){1}$/i ";

foreach($str   as   $key=> $val)
{
        $key++;
        if(preg_match($pattern,$val))
                echo   "
right! 　 ".$val;
        else
                echo   "
error! 　 ".$val;
}

//方法三

//匹配yyyyyy
"/([^].*)/i"

//匹配href="xxxxxx"
s*<[aa]{1}s*href="([^"]*)"s*>([^<]*)

$reg = "[^""]*)2)|(?[^s>]+))[ss]*?>";

?>

本文来源：http://www.gdgbn.com/aspjiaocheng/27522/