sub getinput {
    my $default = shift;
    my $value;
    eval { 
        local $SIG{ALRM} = sub { die "alarm clock restart" };
        alarm 10; 

        # your code here, read <STDIN>
        $value = ...

        alarm 0; 
    };
    if ($@ and $@ !~ /alarm clock restart/) { return $default }
    return $value;
}