file_exists() returns false, but the file DOES exist

user_618622 0
Viewed 75967

I'm having a very weird issue with file_exists(). I'm using this function to check if 2 different files in the same folders do exist. I've double-checked, they BOTH do exist.

echo $relative . $url['path'] . '/' . $path['filename'] . '.jpg';
Result: ../../images/example/001-001.jpg

echo $relative . $url['path'] . '/' . $path['filename'] . '.' . $path['extension'];
Result: ../../images/example/001-001.PNG

Now let's use file_exists() on these:

var_dump(file_exists($relative . $url['path'] . '/' . $path['filename'] . '.jpg'));
Result: bool(false)

var_dump(file_exists($relative . $url['path'] . '/' . $path['filename'] . '.' . $path['extension']));
Result: bool(true)

I don't get it - both of these files do exist. I'm running Windows, so it's not related to a case-sensitive issue. Safe Mode is off.

What might be worth mentioning though is that the .png one is uploaded by a user via FTP, while the .jpg one is created using a script. But as far as I know, that shouldn't make a difference.

Any tips?

Thanks

wamp apache windows php
15 Answers

I have a new reason this happens - I am using PHP inside a Docker container with a mounted volume for the codebase which resides on my local host machine.

I was getting file_exists == FALSE (inside Composer autoload), but if I copied the filepath into terminal - it did exist! I tried the clearstatche(), checked safe-mode was OFF.

Then I remembered the Docker volume mapping: the absolute path on my local host machine certainly doesn't exist inside the Docker container - which is PHP's perspective on the world.

(I keep forgetting I'm using Docker, because I've made shell functions which wrap the docker run commands so nicely...)

user_2092880

In my case, the problem was a misconception of how file_exists() behaves with symbolic links and .. ("dotdot" or double period) parent dir references. In that regard, it differs from functions like require, include or even mkdir().

Given this directory structure:

/home/me/work/example/
  www/
/var/www/example.local/
  tmp/
  public_html -> /home/me/work/example/www/

file_exists('/var/www/example.local/public_html/../tmp/'); would return FALSE even though the subdir exists as we see, because the function traversed up into /home/me/work/example/ which does not have that subdir.

For this reason, I have created this function:

/**
 * Resolve any ".." ("dotdots" or double periods) in a given path.
 *
 * This is especially useful for avoiding the confusing behavior `file_exists()`
 * shows with symbolic links.
 *
 * @param string $path
 *
 * @return string
 */
function resolve_dotdots( string $path ) {

    if (empty($path)) {
        return $path;
    }

    $source = array_reverse(explode(DIRECTORY_SEPARATOR, $path));
    $balance = 0;
    $parts = array();

    // going backwards through the path, keep track of the dotdots and "work
    // them off" by skipping a part. Only take over the respective part if the
    // balance is at zero.
    foreach ($source as $part) {
        if ($part === '..') {
            $balance++;

        } else if ($balance > 0) {
            $balance--;

        } else {
            array_push($parts, $part);
        }
    }

    // special case: path begins with too many dotdots, references "outside
    // knowledge".
    if ($balance > 0) {
        for ($i = 0; $i < $balance; $i++) {
            array_push($parts, '..');
        }
    }

    $parts = array_reverse($parts);
    return implode(DIRECTORY_SEPARATOR, $parts);
}
user_21264420

I just encountered this same problem and I solved it in a mysterious way. After inserting a a filepath I copied from Windows File explorer. file_exists() keeps returning false continuously, but if I copy same path from VSCode editor it works perfectly.

After dumping variables with var_dump($path); I noticed something mysterious. For path I copied from file explorer it shows length 94. For path I copied from VSCode Editor it shows length 88.

Both path look same length on my code Editor.

My suggestion: if string contain hidden characters, it may fail and not work.

user_91824960
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