Is file_exists() compatible with timthumb.php? [closed]

Question

I'm using the latest timthumb script to generate my post thumbnails and include them along with the excerpt. Though I only want the thumbnails to load if their files actually exist, otherwise I don't even want the image placeholder to load.

I'm going to be using this on a multi-user network, which is still in the early stages of development. And I want to test if the posts author has neglected to properly add the "thumb" custom field, which if they have, would normally return a 404 not found error.

So I've put the following code in my loop which first determines if the post has any images then using the file path for the first image listed in the post checks if the file exists.

<?php
$content = $post->post_content;
$searchimages = '~<img [^>]* />~';
preg_match_all($searchimages, $content, $pics);
$iNumberOfPics = count($pics[0]);
if($iNumberOfPics > 0){
    $blogTemplate = get_bloginfo('template_directory');
    $imgSrc = get_post_meta($post->ID, "thumb", $single = true);
    $imgSrc = $blogTemplate . "/scripts/timthumb.php?src=" . $imgSrc . "&w=300&zc=1";

    if(file_exists($imgSrc)){ ?>
        <a href="<?php the_permalink(); ?>" class="thumb" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><img src="<?php echo $imgSrc; ?>" alt="<?php the_title(); ?>" /></a><?php              
    }
}
?>

I've tested the $imgSrc string that's outputted which is valid, it is an existing file though the my file_exists($imgSrc) function always returns false. I'm left wondering if the timthumb script is compatible with the file_exists() function?

Answer 1

The file_exists() function is a built in php function and should work everywhere. But with the way you're doing it, is wrong. You cannot use a query string within a php file to check if the file exists. Just because its a valid link, doesn't mean the file_exists(). There is no file on your server by the name of /scripts/timthumb.php?src=*

You need to do the following to your code:

<?php
$content = $post->post_content;
$searchimages = '~<img [^>]* />~';
preg_match_all($searchimages, $content, $pics);
$iNumberOfPics = count($pics[0]);
if($iNumberOfPics > 0){
    $blogTemplate = get_bloginfo('template_directory');
    $imgSrc = get_post_meta($post->ID, "thumb", $single = true);

    if(file_exists($imgSrc)){ 
    $imgSrc = $blogTemplate . "/scripts/timthumb.php?src=" . $imgSrc . "&w=300&zc=1";
    ?>
        <a href="<?php the_permalink(); ?>" class="thumb" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><img src="<?php echo $imgSrc; ?>" alt="<?php the_title(); ?>" /></a><?php              
    }
}
?>

This way you're actually checking for the real file name and then changing the url to the query string url later, after you know the file exists.

Answer 2

file_exists(); and is_readable(); (which I've decided to go for instead as it detects if the file is readable as well as if it exists) both require the $_SERVER['DOCUMENT_ROOT']; variable to be called as the file is physically stored on the file server's HDD and therefore replaces the need to declare the domain name in the function. Do it like this:

is_readable($_SERVER['DOCUMENT_ROOT'].'/'.preg_replace('/(https?:\/\/)?(www\.)?+(example\.com)\/?/','',$imgSrc);

no need to write any special apache code.