<?php

class downloader {
    public $remote_file_url = '';
    public $local_filename = '';
    
    public function __construct() {
    }
    public function __destruct() {
    }
    
    public function setLocalFilename($filename) {
        $this->local_filename = $filename;
    }
    public function setRemoteFileURL($url) {
        $this->remote_file_url = $url;
    }
    
    public function doDownload() {
        if($this->remote_file_url!='') {
            /* Remove any previous download */
            if(file_exists($this->local_filename)) {
                exec("rm \"". $this->local_filename . "\"");
            }
            if(file_exists(str_replace('.gz','',$this->local_filename))) {
                exec("rm \"". str_replace('.gz','',$this->local_filename) . "\"");
            }
            /* Do download */
            exec('wget -q -O ' . $this->local_filename . ' ' . $this->remote_file_url);
            if(file_exists($this->local_filename)) {
                exec('gunzip ' . $this->local_filename);
                return true;
            }
            else {
                return false;
            }
        }
        else {
            return false;
        }
    }
    
}

$downloader = new downloader;

$downloader->setRemoteFileURL('http://url.to.file.here');

$downloader->setLocalFilename('export_latest.xml.gz');
var_dump($downloader->doDownload());

?>