This is a little chunk of code that i use to show the source of a file, i took part of the idea from a example i found on another php function page.

This code takes a php file and highlights it and places a line number next to it.  Great for on the fly debugging.

<?php
// Get a file into an array
$lines = file('index.php');

// Loop through our array, show HTML source as HTML source; and line numbers too.
echo('<table border=0 cellpadding=0 cellspacing=0>');
foreach ($lines as $line_num => $line) {
    echo('<tr>');
    echo('<td bgcolor = "#cccccc">');
    echo('<code>' . ($line_num + 1) . '</code>');
    echo('</td>');
    echo('<td>');          
    highlight_string($line);
    echo('</td>');
    echo('</tr>');
}

?>