Download FreeBSD packages with dependencies

Just code, no comments:

<?php

#Where to save downloaded packages
$dir = '/tmp/packages';

#FTP server with all packages
$ftp = 'ftp://ftp6.ru.freebsd.org/pub/FreeBSD/ports/i386/packages-7.2-release/All';
 
#Target packages we need to retrieve 
$packages = array(
    'bash-3.2.48_1',
    'bzip2-1.0.5',
    'curl-7.19.4',
    'mc-4.6.2',
    'mysql-server-5.0.77_1',
    'php5-mysqli-5.2.9',
    'postgresql-server-8.3.7',
    'vim-7.2.132',
    'wget-1.11.4',
    'zip-3.0'
);

#Load packages info from previously downloaded INDEX file (ftp://ftp6.ru.freebsd.org/pub/FreeBSD/ports/i386/packages-7.2-release/All/INDEX) 
function get_tree() {
    $handle = fopen('INDEX', 'r');
    $tree = array();
    while (($data = fgetcsv($handle, 0, '|')) !== FALSE) {
        $tree[$data[0]] = $data[8];
    }
    fclose($handle);
    return $tree;
}

$tree = get_tree();

#Calculate dependencies
for ($i = 0; $i < sizeof($packages); $i++) {
    if (isset($tree, $packages[$i])) {
        $deps = explode(' ', $tree[$packages[$i]]);
        foreach ($deps as $dep) {
            if (strlen($dep)>0 && !in_array($dep, $packages)) {
                $packages[] = $dep;
            }
        }
    }
}

#Downloading
foreach ($packages as $package) {
    file_put_contents($dir.'/'.$package.'.tbz', file_get_contents($ftp.'/'.$package.'.tbz'));
    echo "$package.tbz\n";
}

?>