C Primer Plus, Fourth Edition

Chapter 15. Bit Fiddling

You will learn about the following in this chapter:

• Operators:

  ~ & |^

  >> <<

  &= |= ^= >>= <<=

• Binary, octal, and hexadecimal number notations (a review)

• Two C facilities for handling the individual bits in a value: bitwise operators and bit fields

With C, you can manipulate the individual bits in a variable. Perhaps you are wondering why anyone would want to. Be assured that sometimes this ability is necessary, or at least useful. For example, a hardware device is often controlled by sending it a byte or two in which each bit has a particular meaning. Also, operating system information about files is often stored by using particular bits to indicate particular items. Many compression and encryption operatations manipulate individual ...