171 if (!open(TTY, "/dev/tty")) {
    172     print "no tty\n";
    173 } else {
    174     my $tpgrp = tcgetpgrp(fileno(*TTY));
    175     my $pgrp = getpgrp();
    176     if ($tpgrp == $pgrp) {
    177         print "foreground\n";
    178     } else {
    179         print "background\n";
    180     }
    181 }