PHP to check file exist on external server using file_get_contents()

Question

Checking file exists on external server using file_get_contents() method, does this method will work properly?

$url_file = "http://website.com/dir/filename.php";
$contents = file_get_contents($url_file);

if($contents){
echo "File Exists!";
} else {
echo "File Doesn't Exists!";
}

No, you cannot check for file existence. URLs do not reference files, just resources (which may or not originate from actual files). You can check for returned content, or [`$http_response_header`](http://php.net/manual/en/reserved.variables.httpresponseheader.php) states though. And you could concretise how you concluded your code does not work, or what you're really trying to accomplish. — mario, Aug 18 '14 at 01:33
that will check if the file has a content or not. You can try other ways to test if the file exits testing just the headers (check HTTP error codes): http://php.net/manual/en/function.get-headers.php — lepe, Aug 18 '14 at 01:34
@lepe: I have control for that files, I can set file has a content or not.. so can I using this method? — Ajie Kurniyawan, Aug 18 '14 at 01:59
@Ajie Kurniyawan: Yes it could work depending on your web server settings. The web server may respond with HTML:
Error 404: Not found
, for example, so it may have a content, but it may not be what you are expecting. I think its easier to check the headers, don't you think? — lepe, Aug 18 '14 at 03:35

score 4 · Accepted Answer · answered Aug 18 '14 at 04:00

4

I think best method for me is using this script:

$file = "http://website.com/dir/filename.php";
$file_headers = get_headers($file);

If file not exists output for $file_headers[0] is: HTTP/1.0 404 Not Found or HTTP/1.1 404 Not Found

Use strpos method to check 404 string if file doesn't exists:

if(strpos($file_headers[0], '404') !== false){
echo "File Doesn't Exists!";
} else {
echo "File Exists!";
}

Thanks for all help :)

answered Aug 18 '14 at 04:00

Ajie Kurniyawan

393
2
18

There are other failures besides 404. – fat_mike Mar 18 '19 at 19:52

score 1 · Answer 2 · answered Aug 18 '14 at 01:37

1

This would work for what you are looking to do. As seen here http://php.net/manual/en/function.file-exists.php#75064

$file = 'http://www.domain.com/somefile.jpg';
$file_headers = @get_headers($file);
if($file_headers[0] == 'HTTP/1.1 404 Not Found') {
    $exists = false;
}
else {
    $exists = true;
}

answered Aug 18 '14 at 01:37

blamonet

592
1
4
13

In my test if file not exists $file_headers[0] get value = 'HTTP/1.0 404 Not Found', so this method not works properly, should I change 1.1 to 1.0? – Ajie Kurniyawan Aug 18 '14 at 01:54
This all depends on the web server. Here is a good article on this: http://stackoverflow.com/questions/2769371/404-header-http-1-0-or-1-1 For me personally, I'd probably do some string manipulations to find 404 in the string and ignore the rest of the string so it would work in both cases. – blamonet Aug 18 '14 at 01:59
If I add this script maybe this method will works? $string = $file_headers[0]; $404 = "404"; $pos = strpos($string, $404); if ($pos === false) { echo "File Exists!"; } else { echo "File Doesn't Exists!"; } – Ajie Kurniyawan Aug 18 '14 at 02:09
@Ajie Kurniyawan: close, don't name your variable: $404, name it for example: $code or use "404" without a variable. (numeric variables are not allowed in PHP). Fixing that, it should work. – lepe Aug 18 '14 at 03:31
@lepe: thanks, I have created an answer for my own question, I think best way is that method.. thanks all for help :) – Ajie Kurniyawan Aug 18 '14 at 04:02

fat_mike · Answer 3 · 2019-03-18T22:33:34.453

Both answers from blamonet and Ajie Kurniyawan are somewhat correct but there are more failures than 404(3xx, 4xx, 5xx responses). There are a lot of HTTP responses that would fail to "get/download" a file from a given server.

So I would suggest to check if 200 OK response.

$file = "http://website.com/dir/filename.php";
$file_headers = @get_headers($file);

if ($file_headers) {
  if (strpos($file_headers[0], ' 200 OK') === true) {
    echo "File Exists";
  } else {
    echo "File Doesn't Exist, Access Denied, URL Moved etc";
    //you can check more responses here 404, 403, 301, 302 etc 
  }
} else {
  echo "Server has not responded. No headers or file to show.";
}

PHP to check file exist on external server using file_get_contents()

Error 404: Not found

3 Answers3