Ok, isto é um exemplo básico e funcional para o que tu pretendes:
<?php
if(isset($_COOKIE['download'])) {
setcookie('download', '', time() - 3600, '/');
header('location: http://dominio.com/arquivo.rar');
//exit;
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="pt" lang="pt">
<head>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title>Download</title>
<script type="text/javascript">
function Set_Cookie( name, value, expires, path, domain, secure ) {
var today = new Date();
today.setTime( today.getTime() );
if ( expires ) {
expires = expires * 1000 * 60;
}
var expires_date = new Date( today.getTime() + (expires) );
document.cookie = name + "=" +escape( value ) +
( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" ) +
( ( path ) ? ";path=" + path : "" ) +
( ( domain ) ? ";domain=" + domain : "" ) +
( ( secure ) ? ";secure" : "" );
}
function fnHide(secs){
secs--;
if(secs>0) {
document.getElementById("waiting").innerHTML = 'Please wait while we transfer your file. Estimated wait time: <b>'+secs+'</b> seconds.';
window.setTimeout("fnHide("+secs+")",1000);
} else {
Set_Cookie('download', '1', 1, '/', '', ''); // -> 1 minuto
document.getElementById("waiting").innerHTML = '<a href="#" onclick="javascript: window.location.reload();">Carregue aqui para fazer download automaticamente</a>';
}
}
</script>
</head>
<body>
<div id="waiting"></div>
<p>
<a href="#" onclick="javascript: fnHide(25); return false;">Download</a>
</p>
</body>
</html>
PS: Mantive a função JavaScript (fnHide) já postada anteriormente.
EDIT: Havia um pequeno erro, já foi corrigido.
