use Getopt::Std;

getopts("lp");  # '-p' and '-l' will be recognized

my $PORTRAIT  = 1 << 3;  # b3 = PORTRAIT orientation
my $LANDSCAPE = 1 << 4;  # b4 = LANDSCAPE

my $LAYOUT_ERROR = $PORTRAIT | $LANDSCAPE;  

my $status = 0;

if (defined ($opt_p)) {
   $status |= $PORTRAIT;
}

if (defined ($opt_l)) {
   $status |= $LANDSCAPE;
}

printf("   \$LANDSCAPE = %016b\n", $LANDSCAPE);
printf("    \$PORTRAIT = %016b\n", $PORTRAIT);
printf("\$LAYOUT_ERROR = %016b\n", $LAYOUT_ERROR);
printf("      \$status = %016b\n", $status);

if ( ($status & $LAYOUT_ERROR) == $LAYOUT_ERROR ) {
   die("ERR: Can't do both PORTRAIT and LANDSCAPE\n");
}

printf("Continuing...\n");