root/releases/0.6rc2/_icons/icon.php

<?php

// User icon serving script.
// Usage: http://URL/{username}/icons/{icon_id}

// Run includes
require_once(dirname(dirname(__FILE__))."/includes.php");
$textlib = textlib_get_instance();

// If an ID number for the file has been specified ...
$id = optional_param('id',0,PARAM_INT);
$default = false;
if (empty($id)) {
    $default = true;
}
// ... and the file exists ...
if (!$file = get_record('icons','ident',$id)) {
    $default = true;
}
// get the user who belongs to this icon..
if (empty($file) || !$user = get_record('users','ident',$file->owner)) {
    $default = true;
}
if (empty($default)) {
    $upload_folder = $textlib->substr($user->username,0,1);
    $filepath = $CFG->dataroot . "icons/" . $upload_folder . "/" . $user->username . "/".$file->filename; 
    if (!file_exists($filepath)) {
        $default = true;
    }
}

if (!empty($default)) {
    $filepath = path.'_icons/data/default.png';
}

$tstamp = filemtime($filepath);
$lm = gmdate("D, d M Y H:i:s", $tstamp) . " GMT";
    
// Send 304s where possible, rather than spitting out the file each time
if (array_key_exists('HTTP_IF_MODIFIED_SINCE',$_SERVER)) {
    $if_modified_since = preg_replace('/;.*$/', '', $_SERVER['HTTP_IF_MODIFIED_SINCE']);
    if ($if_modified_since == $lm) {
        header("{$_SERVER['SERVER_PROTOCOL']} 304 Not Modified");
        exit;
    }
}

// Send last-modified header to enable if-modified-since requests
if ($tstamp < time()) {
    header("Last-Modified: " . $lm);
}

// Then output some appropriate headers and send the file data!
require_once($CFG->dirroot.'lib/filelib.php');
$mimetype = mimeinfo('type',$file->filename);

// see if we must resize it.
$constraint1 = strtolower(optional_param('constraint1'));
$size1 = optional_param('size1');
$constraint2 = strtolower(optional_param('constraint2'));
$size2 = optional_param('size2');

$url =  $CFG->wwwroot.'units/phpthumb/phpThumb.php?src='.urlencode($filepath);
// if size == 100, leave it.
if (!empty($constraint1) && !empty($size1) && ($constraint1 == 'h' || $constraint1 = 'w') && $size1 != 100) {
    $url .= '&'.$constraint1.'='.$size1;
    $phpthumb = true;
}
if (!empty($constraint2) && !empty($size2) && ($constraint2 == 'h' || $constraint2 = 'w') && $size2 != 100) {
    $url .= '&'.$constraint2.'='.$size2;
    $phpthumb = true;
}
if (!empty($phpthumb)) {
    header("Location: $url");
    exit;
}
// "Cache-Control: private" to allow a user's browser to cache the file, but not a shared proxy
// Also to override PHP's default "DON'T EVER CACHE THIS EVER" header
header("Cache-Control: private");

header("Content-type: $mimetype");
readfile($filepath);
            
?>