#!/usr/bin/perl

use IO::File;

$stuff="0.4312342134234234";
$morestuff="0.2432134234342342";

$fh=IO::File->new(">/tmp/foo2.txt");
$fh=sprintf($fh <<"__EOFOO__", $stuff, $morestuff);
Some stuff: %.4f
Some more stuff %.4f
__EOFOO__