Check if links are broken in php

Question

I wonder if there is any good PHP script (libraries) to check if link are broken? I have links to documents in a mysql table and could possibly just check if the link leads

Answer 1

You can do this in few ways:

First way - curl

function url_exists($url) {
    $ch = @curl_init($url);
    @curl_setopt($ch, CURLOPT_HEADER, TRUE);
    @curl_setopt($ch, CURLOPT_NOBODY, TRUE);
    @curl_setopt($ch, CURLOPT_FOLLOWLOCATION, FALSE);
    @curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    $status = array();
    preg_match('/HTTP\/.* ([0-9]+) .*/', @curl_exec($ch) , $status);
    return ($status[1] == 200);
}

Second way - if you dont have curl installed - get headers

function url_exists($url) {
    $h = get_headers($url);
    $status = array();
    preg_match('/HTTP\/.* ([0-9]+) .*/', $h[0] , $status);
    return ($status[1] == 200);
}

Third way - fopen

function url_exists($url){
    $open = @fopen($url,'r');
    if($handle !== false){
       return true;
    }else{
       return false;
    }
}

First & second solutions

Answer 2

Try this:

$url = '[your_url]';
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

$result = curl_exec($curl);

if ($result === false) {
    echo 'broken url';
} else {
    $newUrl = curl_getinfo($curl, CURLINFO_EFFECTIVE_URL);

    if ($newUrl !== $url) {
        echo 'redirect to: ' . $newUrl;
    }
}
curl_close($curl);

Answer 3

As quick workaround check, you can use the global variable $http_response_header with file_get_contents() function.

For example (extracted from PHP documentation):

<?php
function get_contents() {
  file_get_contents("http://example.com");
  var_dump($http_response_header);
}
get_contents();
var_dump($http_response_header);

Then check the status code in first line for a "HTTP/1.1 200 OK" or other HTTP status codes.

Answer 4

You can check for broken link using this function:

function check_url($url) {

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HEADER, 1);
    curl_setopt($ch , CURLOPT_RETURNTRANSFER, 1);
    $data = curl_exec($ch);
    $headers = curl_getinfo($ch);
    curl_close($ch);

    return $headers['http_code'];
}

You need to have CURL installed for this to work. Now you can check for broken links using:

$check_url_status = check_url($url);
if ($check_url_status == '200')
   echo "Link Works";
else
   echo "Broken Link";

Also check this link for HTTP status codes : HTTP Status Codes

I think you can also check for 301 and 302 status codes.

Also another method would be to use get_headers function . But this works only if your PHP version is greater than 5 :

function check_url($url) {
   $headers = @get_headers( $url);
   $headers = (is_array($headers)) ? implode( "\n ", $headers) : $headers;

   return (bool)preg_match('#^HTTP/.*\s+[(200|301|302)]+\s#i', $headers);
}

In this case just check the output :

if (check_url($url))
   echo "Link Works";
else
   echo "Broken Link";

Hope this helps you :).