Check if download link is dead in php? - php

Question

If I get title of the page, I can tell the download link is active or dead.
For example: "Free online storage" is title of dead link and "[file name]" is the title of active link (mediafire). But my page takes too long to respond, so is there any other way to check if a download link is active or dead?
That is what i have done:
<?php
function getTitle($Url){
$str = file_get_contents($Url);
if(strlen($str)>0){
preg_match("/\<title\>(.*)\<\/title\>/",$str,$title);
return $title[1];
}
}
?>

Answer 1

Do not perform a GET request, which downloads the whole page/file, but HEAD request, which gets only the HTTP headers, and check if the status is 200, and the content-type is not text/html

Answer 2

Something like this...
function url_validate($link)
{
#[url]http://www.example.com/determining-if-a-url-exists-with-curl/[/url]
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $link);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_MAXREDIRS, 10); //follow up to 10 redirections - avoids loops
$data = curl_exec($ch);
curl_close($ch);
preg_match_all("/HTTP\/1\.[1|0]\s(\d{3})/",$data,$matches);
$code = end($matches[1]);
if(!$data)
{
return(false);
}
else
{
if($code==200)
{
return(true);
}
elseif($code==404)
{
return(false);
}
}
}
You can safely use any cURL library function. It is legitimate and thus would not regarded as a hacking attempt. The only requirement is that your web hosting company has cURL extension installed, which is very likely.

Answer 3

cURL should do the job. You can check the headers returned and the text content as well if you want.