file_exists() returns false, but the file DOES exist

Question

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 ex

Answer 1

Try using DIRECTORY_SEPARATOR instead of '/' as separator. Windows uses a different separator for file system paths (backslash) than Linux and Unix systems.

Answer 2

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);
}

Answer 3

Results of the file_exists() are cached, so try using clearstatcache(). If that not helped, recheck names - they might be similar, but not same.

Answer 4

have you tried manual entry. also your two extensions seem to be in different case

   var_dump(file_exists('../../images/example/001-001.jpg'));
   var_dump(file_exists('../../images/example/001-001.PNG'));

Answer 5

A custom_file_exists() function inspired by @Timur, @Brian, @Doug and @Shahar previous answers:

function custom_file_exists($file_path=''){
    $file_exists=false;

    //clear cached results
    //clearstatcache();

    //trim path
    $file_dir=trim(dirname($file_path));

    //normalize path separator
    $file_dir=str_replace('/',DIRECTORY_SEPARATOR,$file_dir).DIRECTORY_SEPARATOR;

    //trim file name
    $file_name=trim(basename($file_path));

    //rebuild path
    $file_path=$file_dir."{$file_name}";

    //If you simply want to check that some file (not directory) exists, 
    //and concerned about performance, try is_file() instead.
    //It seems like is_file() is almost 2x faster when a file exists 
    //and about the same when it doesn't.

    $file_exists=is_file($file_path);

    //$file_exists=file_exists($file_path);

    return $file_exists;
}

Answer 6

It's because of safe mode. You can turn it off or include the directory in safe_mode_include_dir. Or change file ownership / permissions for those files.

php.net: file_exists()
php.net: safe mode