PHP「建议收藏」

http://www.w3school.com.cn/php/

function isdomain($domain)  
{  
    $pattern = '[a-zA-Z0-9][-a-zA-Z0-9]{0,62}(\.[a-zA-Z0-9][-a-zA-Z0-9]{0,62})+\.?';
    return eregi($pattern, $domain) ? true : false;
}

$string = preg_replace('/\s(?=\s)/', '\\1',$string);

$string = preg_replace('/^\s+/m', '',$string);

http://www.shucunwang.com/RunCode/php/

http://www.jb51.net/article/38599.htm

http://www.toutiao.com/a6203566288927539714/