Please note the fashion in which readdir()'s
     return value is checked in the examples below. We are explicitly
     testing whether the return value is identical to (equal to and of
     the same type as--see Comparison
     Operators for more information) FALSE since otherwise,
     any directory entry whose name evaluates to FALSE will stop the
     loop (e.g. a directory named "0").
    
<?php
// Note that !== did not exist until 4.0.0-RC2
if ($handle = opendir('/path/to/files')) {
    echo "Directory handle: $handle\n";
    echo "Files:\n";
    /* This is the correct way to loop over the directory. */
    while (false !== ($file = readdir($handle))) {
        echo "$file\n";
    }
    /* This is the WRONG way to loop over the directory. */
    while ($file = readdir($handle)) {
        echo "$file\n";
    }
    closedir($handle);
}
?>