check url exist

url_exist.php

<?php 

/**
 * 判断URL是否存在/可访问
 * @param  string $url url
 * @return bool      存在返回true。不存在返回false
 */
function url_exist($url){
	$curl = curl_init();
	curl_setopt($curl, CURLOPT_URL, $url);
	curl_setopt($curl, CURLOPT_TIMEOUT, 3);
	curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 3);
	curl_setopt($curl, CURLOPT_NOBODY, 1);

	curl_exec($curl);
	$http_code = curl_getinfo($curl,CURLINFO_HTTP_CODE);
	if ($http_code === 200) {
		return true;
	} else {
		return false;
	}
}

 ?>