file_exists giving false negative

doby48

I am trying to verify if a file exists or not before calling an img tag. I have formatted this several ways and continue to get false negatives as I am seeing "File doesnt exist" even if it does. The full path correctly shows and yes I can copy/paste that path directly into a browser and see the image that my script claims isnt there. What have I done wrong? Is it because I am calling a varliable withing a variable and it is not read early enough? If so can someone offer a solution? Here is my script:

<?php
$filename = "http://mydomain.com/authors/".$authordata->ID.".gif";
if (file_exists($filename)) {
    echo "The file $filename exists";
} else {
    echo "The file $filename does not exist";
}
?>

bradgrafelman

If the file is on the same server as the script, don't use an HTTP path; it's rather wasteful/slow in terms of resources used versus just a local filesystem request, plus it's apparently finicky for this situation.

doby48

Actually I had just used the full URL for testing but have now changed the url format instead just to see if that fixed it. Still the same problem as I continue to get false negatives when the file does in fact exist.

Just above my file_exists code I also am using the same URL for an img and it correctly shows the image.

<img src="../authors/<?php echo $authordata->ID; ?>.gif" />

bradgrafelman

What "format" are you now using? Can you give us an example/updated code?

doby48

Sure thing... here is what I am now using which tells me the file doesnt exist.

<?php 
$filename = "../authors/".$authordata->ID.".gif"; 
if (file_exists($filename)) { 
    echo "The file $filename exists"; 
} else { 
    echo "The file $filename does not exist"; 
} 
?>

However, if I use the same URL for am IMG tag then it correctly displays the image. Here is my code I am using for an IMG tag.

<img src="../authors/<?php echo $authordata->ID; ?>.gif" />

bradgrafelman

Thats... odd.

Will it consistently report that it does not exist? In other words, can you sit there and refresh the page several times and it will consistently say that it does not exist? You might try swapping out [man]file_exists/man for [man]is_file/man and see if that makes any difference.

Also, what version of PHP are you running?

doby48

I'm running PHP 5.2.5

I just tried using is_file and still the same results. It tells me that the file doesnt exist but lists out correctly the path to the image still.

This happens constantly, so yes if I keep hitting refresh then it tells me every time that the file doesnt exist. It shouldnt make a difference that my variable $authordata (used in my $filename variable) is a global variable should it?

bradgrafelman

It must be something with the permissions of the file or the path still isn't quite right... try echo'ing out realpath($filename and seeing if it visually looks right.

Also, is display_errors set to On and error_reporting to E_ALL ? If so, try using [man]file_get_contents/man to try and get PHP to read data from the file; the error message should indicate if it's a permissions problem or if PHP truly can't find the file with the given path.

doby48

The path is showing correctly and the same was what I was calling upon failure. My original code had the $filename variable written out and the path was showing correctly. I used realpath() instead and shows the same path which is correct. If I copy/paste the path shown into a browser it correctly displays the image I was checking for.

doby48

Ok finally got it...

Playing around with the realpath I just changed my script to include that:

<?php
$filename = realpath("/uploads/authors/".$authordata->ID.".gif");
if (file_exists($filename)) {
    echo "The file $filename exists";
} else {
    echo "The file $filename does not exist";
}
?>

And its working as expected now. Not sure why I would have to use the realpath for it work so that seems odd to me but its working at least.