$rin = $win = $ein = '';
vec($rin, fileno(STDIN), 1) = 1;
vec($win, fileno(STDOUT), 1) = 1;
$ein = $rin | $win;

sub fhbits {
    local(@fhlist) = @_;
    local($bits);
    for (@fhlist) {
	vec($bits, fileno($_), 1) = 1;
    }
    $bits;
}
$rin = &fhbits(STDIN,TTY,SOCK);

($nfound, $timeleft) =
	select($rout=$rin, $wout=$win, $eout=$ein, $timeout);

$nfound = select($rout=$rin, $wout=$win, $eout=$ein, undef);

select(undef, undef, undef, 4.75);
