//方法一

function file_exists($url)

{

$ch = curl_init();

curl_setopt($ch, curlopt_url,$url);

curl_setopt($ch, curlopt_nobody, 1); // 不下载

curl_setopt($ch, curlopt_failonerror, 1);

curl_setopt($ch, curlopt_returntransfer, 1);

if(curl_exec($ch)!==false)

return true;

else

return false;

}

//方法二

function file_exists2($url)

{

if(file_get_contents($url,0,null,0,1))

return 1;

else

return 0;

}

//方法三

function file_exists($url) {

$curl = curl_init($url);

// 不取回数据

curl_setopt($curl, CURLOPT_NOBODY, true);

// 发送请求

$result = curl_exec($curl);

$found = false;

// 如果请求没有发送失败

if ($result !== false) {

// 再检查http响应码是否为200

}

$url = "http://www.baidu.com/img/baidu_sylogo1.gif";

$info = parse_url($url);

$fp = fsockopen($info['host'], 80,$errno, $errstr, 30);

fputs($fp,"GET {$info['path']} HTTP/1.1\r\n");

fputs($fp, "Host: {$info['host']}\r\n");

fputs($fp, "Connection: close\r\n\r\n");

$headers = array();

while(!feof($fp)) {

$line = fgets($fp);

if($line != "\r\n") {

$headers[] = $line;

}else {

break;

}

}

echo "<pre>";

print_r($headers);

<?php

$url = 'http://www.test.com/images/test.jpg';

if( @fopen( $url, 'r' ) )

{

echo 'File Exits';

}

else

{

echo 'File Do Not Exits';

}

?>

<?php

$url2 = 'http://www.test.com/test.jpg';

$ch = curl_init();

$timeout = 10;

curl_setopt ($ch, CURLOPT_URL, $url2);

curl_setopt($ch, CURLOPT_HEADER, 1);

curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout);

$contents = curl_exec($ch);

//echo $contents;

if (preg_match("/404/", $contents)){

echo '文件不存在';

}

?>