Script that allows to check unix file system's security issues

browse.php

<?php
 
echo "<pre>\n";
 
if (ini_get('safe_mode')) {
    echo "[safe_mode enabled]\n\n";
} else {
    echo "[safe_mode disabled]\n\n";
}
 
if (isset($_GET['dir'])) {
    ls($_GET['dir']);
} elseif (isset($_GET['file'])) {
    cat($_GET['file']);
} else {
    ls('/');
}
 
echo "</pre>\n";
 
function ls($dir)
{
    $handle = dir($dir);
    while ($filename = $handle->read()) {
        $size = filesize("$dir$filename");
 
        if (is_dir("$dir$filename")) {
            if (is_readable("$dir$filename")) {
                $line = str_pad($size, 15);
                $line .= "<a href="{$_SERVER['PHP_SELF']}?dir=$dir$filename/">$filename/</a>";
            } else {
                $line = str_pad($size, 15);
                $line .= "$filename/";
            }
        } else {
            if (is_readable("$dir$filename")) {
                $line = str_pad($size, 15);
                $line .= "<a href="{$_SERVER['PHP_SELF']}?file=$dir$filename">$filename</a>";
            } else {
                $line = str_pad($size, 15);
                $line .= $filename;
            }
        }
 
        echo "$line\n";
    }
 
    $handle->close();
}
 
function cat($file)
{
    $contents = file_get_content($file);
    echo htmlentities($content, ENT_QUOTES, 'UTF-8'); 
}
 
?>