Get mime type of external file using cURL and php

You can use a HEAD request via curl. Like:

$ch = curl_init();
$url = 'http://sstatic.net/so/img/logo.png';
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_NOBODY, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

$results = explode("\n", trim(curl_exec($ch)));
foreach($results as $line) {
    if (strtolower(strtok($line, ':')) == 'content-type') {
        $parts = explode(":", $line);
        echo trim($parts[1]);
    }
}

Which returns: image/png

PHP curl_getinfo()

<?php
  # the request
  $ch = curl_init('http://www.google.com');
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_exec($ch);

  # get the content type
  echo curl_getinfo($ch, CURLINFO_CONTENT_TYPE);

  # output
  text/html; charset=ISO-8859-1
?>

curl

curl -I http://www.google.com

output

HTTP/1.1 301 Moved Permanently
Location: http://www.google.com/
Content-Type: text/html; charset=UTF-8
Date: Fri, 09 Apr 2010 20:35:12 GMT
Expires: Sun, 09 May 2010 20:35:12 GMT
Cache-Control: public, max-age=2592000
Server: gws
Content-Length: 219

If you are ok with a more elegant Zend Framework version, here is a class which makes use of Zend_Http_Client component.

Use it like so:

$sniffer = new Smartycode_Http_Mime(); 
$contentType = $sniffer->getMime($url);