<?php
$_pushfile = 'z.zip';
if( is_file( $_pushfile )){
	$_fsize = filesize( $_pushfile );
	$_flast = date( "D, d M Y H:i:s T" , filemtime( $_pushfile ));
	header("Content-Type: application/zip");
	header("Content-Disposition: attachment; filename=hoge.zip");
	header("Last-Modified: $_flast" );
	header( "Cache-Control: no-cache" );
	header("Accept-Ranges: bytes");
	header("Content-Length: $_fsize");
	readfile( $_pushfile );
}
?>