msl@64Lucid:~/perl$ ./if2
Testing 0: Neither bit is set
Testing 1: Only bit 0 is set
Testing 2: Only bit 1 is set
Testing 3: Both bits 0 and 1 are set
Testing 4: Neither bit is set
Testing 5: Only bit 0 is set
Testing 6: Only bit 1 is set
Testing 7: Both bits 0 and 1 are set
msl@64Lucid:~/perl$