Correct PHP way to check if external image exists? - php

Question

I know that there are at least 10 the same questions with answers but none of them seems to work for me flawlessly. I'm trying to check if internal or external image exists (is image URL valid?).
fopen($url, 'r') fails unless I use #fopen():
Warning: fopen(http://example.com/img.jpg) [function.fopen]: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in file.php on line 21
getimagesize($img) fails when image doesn't exist (PHP 5.3.8):
Warning: getimagesize() [function.getimagesize]: php_network_getaddresses: getaddrinfo failed
CURL fails because it isn't supported by some servers (although it's present mostly everywhere).
fileExists() fails because it doesn't work with external URLs and
can't possibly check if we're dealing with image.
Four methods that are the most common answers to such question are wrong. What would be the correct way to do that?

Answer 1

getimagesize($img) fails when image doesn't exist: am not sure you understand what you want .....
FROM PHP DOC
The getimagesize() function will determine the size of any given image file and return the dimensions along with the file type and a height/width text string to be used inside a normal HTML IMG tag and the correspondant HTTP content type.
On failure, FALSE is returned.
Example
$img = array("http://i.stack.imgur.com/52Ha1.png","http://example.com/img.jpg");
foreach ( $img as $v ) {
echo $v, getimagesize($v) ? " = OK \n" : " = Not valid \n";
}
Output
http://i.stack.imgur.com/52Ha1.png = OK
http://example.com/img.jpg = Not valid
getimagesize works just fine
PHP 5.3.19
PHP 5.4.9
Edit
#Paul .but your question is essentially saying "How do I handle this so I won't get an error when there's an error condition". And the answer to that is "you can't". Because all these functions will trigger an error when there is an error condition. So (if you don't want the error) you suppress it. None of this should matter in production because you shouldn't be displaying errors anyway ;-) – DaveRandom

Answer 2

This code is actually to check file... But, it does works for images!
$url = "http://www.myfico.com/Images/sample_overlay.gif";
$header_response = get_headers($url, 1);
if ( strpos( $header_response[0], "404" ) !== false )
{
// FILE DOES NOT EXIST
}
else
{
// FILE EXISTS!!
}

Answer 3

function checkExternalFile($url)
{
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_exec($ch);
$retCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
return $retCode;
}
$fileExists = checkExternalFile("http://example.com/your/url/here.jpg");
// $fileExists > 400 = not found
// $fileExists = 200 = found.

Answer 4

If you're using PHP >=5.0.0 you can pass an additional parameter into fopen to specify context options for HTTP, among them whether to ignore failure status codes.
$contextOptions = array( 'http' => array('ignore_errors' => true));
$context = stream_context_create($contextOptions);
$handle = fopen($url, 'r', false, $context);

Answer 5

Use fsockopen, connect to the server, send a HEAD request and see what status you get back.
The only time you need to be aware of problems is if the domain doesn't exist.
Example code:
$file = "http://example.com/img.jpg";
$path = parse_url($file);
$fp = #fsockopen($path['host'],$path['port']?:80);
if( !$fp) echo "Failed to connect... Either server is down or host doesn't exist.";
else {
fputs($fp,"HEAD ".$file." HTTP/1.0\r\n"
."Host: ".$path['host']."\r\n\r\n");
$firstline = fgets($fp);
list(,$status,$statustext) = explode(" ",$firstline,3);
if( $status == 200) echo "OK!";
else "Status ".$status." ".$statustext."...";
}

Answer 6

You can use the PEAR/HTTP_Request2 Package for this. You can find it here
Here comes an example. The Example expects that you have installed or downloaded the HTTP_Request2 package properly. It uses the old style socket adapter, not curl.
<?php
require_once 'HTTP/Request2.php';
require_once 'HTTP/Request2/Adapter/Socket.php';
$request = new HTTP_Request2 (
$your_url,
HTTP_Request2::METHOD_GET,
array('adapter' => new HTTP_Request2_Adapter_Socket())
);
switch($request->send()->getResponseCode()) {
case 404 :
echo 'not found';
break;
case 200 :
echo 'found';
break;
default :
echo 'needs further attention';
}

Answer 7

I found try catch the best solution for this. It is working fine with me.
try{
list($width, $height) = getimagesize($h_image->image_url);
}
catch (Exception $e)
{
}

Answer 8

I know you wrote "without curl" but still, somebody may find this helpfull:
function curl_head($url) {
$ch = curl_init($url);
//curl_setopt($ch, CURLOPT_USERAGENT, 'Your user agent');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HEADER, 1); # get headers
curl_setopt($ch, CURLOPT_NOBODY, 1); # omit body
//curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1); # do SSL check
//curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2); # verify domain within cert
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1); # follow "Location" redirs
//curl_setopt($ch, CURLOPT_TIMEOUT_MS, 700); # dies after 700ms
$result = curl_exec($ch);
curl_close($ch);
return $result;
}
print_r(curl_head('https://www.example.com/image.jpg'));
You will see someting like this HTTP/1.1 200 OK or HTTP/1.1 404 Not Found in returned header array. You can do also multiple parallel requests with curl multi.

Answer 9

There are multiple steps, there is no single solution:
Validate URL
Check whether the file is available (can be done directly with step 3)
Download the image into a tmp file.
Use getimagesize to check the size of the image.
For this kind of work you can catch the exceptions and handle them well to define your answer. In this case you could even suppress errors because it's intended that they trick might fail. So you handle the errors correctly.
Because it's not possible to do a 100% check on it without having the actual image downloaded. So step 1 and 2 are required, 3 and 4 optional for a more definitive answer.