PHP file_exists returns false when variable is in file name

Question

I want to check if a jpeg file exists on my server. However, when I check it, the return value is false.

clearstatcache();

// the $img variable is dynamically got from $split[1] which is something like image.jpeg" />
$img = str_replace('"','',$split[1]); // remove double quotes
$img = str_replace('/>','',$img); // remove img end tag
$img = str_replace(' ','',$img); // remove spaces

$filename = "uploads/image.jpeg"; // original file name
$fn = "uploads/".$img; // file name with dynamic variable in it
if(file_exists($fn)){
       echo "yes";
}else{
       echo "no";
}

// Check if the two strings are the same and they are
if($fn == $filename){
       echo "same";
}

The original static file name returns back yes, while the dynamic one gives back no. I checked and safe_mode is off on my server and the two variables ($fn and $filename) are completely the same. If I just simply make $img equal to image.jpeg without any str_replace it also gives back true and echos out yes.
Overall, I do not know what is the problem with the $img variable and why does it give me back two different results, if the variables are the same?

Answer 1

You have some serious flaw in your debugging logic somewhere, try this:

echo '<hr/>';

clearstatcache();

// the $img variable is dynamically got from $split[1] which is something like image.jpeg" />
$img = str_replace('"','',$split[1]); // remove double quotes
$img = str_replace('/>','',$img); // remove img end tag
$img = str_replace(' ','',$img); // remove spaces

$filename = "uploads/image.jpeg"; // original file name
$fn = "uploads/".$img; // file name with dynamic variable in it
if(file_exists($fn)){
    echo '$fn: yes';
    echo '<br/>';
}else{
    echo '$fn: no';
    echo '<br/>';
}

if(file_exists($filename)){
    echo '$filename: yes';
    echo '<br/>';
}else{
    echo '$filename: no';
    echo '<br/>';
}

// Check if the two strings are the same and they are
if($fn == $filename){
    echo "same";
    echo '<br/>';
}
else
{
    echo 'different';
    echo '<br/>';
}

echo '<pre>';
var_dump( $split[1], $filename, $fn )
echo '</pre>';

echo '<hr/>';