Checking that a file exists

Dhal

I'm having a bit of a problem with a script that runs as part of a larger page - the script fetches a text file from another server, parses whats in it and displays the results.

Sometimes the server on which this text file is located is not available. I use file_get_contents to retrieve this file, with a conditional that if the result of file_get_contents is false, a file unavailable' message will appear. Unfortunately instead when the file is unavailable, the entire page hangs for a good 30 seconds and ends up displaying an error message, effectively rendering the entire page useless. Stranger, is the fact that if i replace the file url with a random url that i know doesn't exist, the script correctly identifies that it doesn't exist instantly.

Here's the code fragment involved:

if ($details = @file_get_contents("http://www.thesite.com/text.txt")) {

// Perform processing

}
else { echo("File unavailable"); 
}

Is there a way to make file_get_contents time out after a couple of seconds instead of creating a huge delay and error message ? Or is there a simpler way of getting around this problem ?

Thanks in advance.

rebelo

What about checking that the file exists before trying to open it? Such as:

<?php

$file = "/path/to/a/file.txt";

if (file_exists($file)) {
  $details = @file_get_contents($file);
} else {
  echo "File unavailable";
}

// Process the $details results.

?>

Dhal

Hi, thanks for the quick reply.

I've tried file_exists before, and tried it again just now to make sure. I'm not sure why, but no matter what file i use it with, it returns false, even with files located on my own server that i know exist.

:bemused:

drawmack

You have to give the script the relative path to the file from your script. For example

 data
    data_file_1.txt
 root
    script.php
    more_data
        data_file_2.txt

To get data_file_1.txt from script.php you would say

file_exists('../data/data_file_1.txt');

To get data_file_2.txt from script.php you would say

file_exists('more_data/data_file_2.txt');

Dhal

Hi,

The file i want to use this with is located on another server, which explains why i can't get file_exists to work with it, it must only work with relative paths to local files, which is no use for what i need it for.

That takes me back to the original problem - i need an alternative to file_get_contents that can timeout if a file isn't there rather than spending 30 seconds trying to reach it and ending with an error page.

drawmack

http://www.hotscripts.com/Detailed/3240.html

rebelo

Why not use fopen() to check if the file is accessible first, then? fopen returns false if the open fails and it allows checking of urls. So just modify the earlier code to:

<?php

$file = "/path/to/a/file.txt";

if (fopen($file, 'r')) {
  $details = @file_get_contents($file);
} else {
  echo "File unavailable";
}

// Process the $details results. 

?>

Dhal

Thanks, i'll give that a try and see how it goes 🙂