http://kor.i2p/books/The%20C%20Programming%20Language%20by%20K&R/chapter2.html
(The standard library function strpbrk does the same job but returns a
pointer to the location.) 2.9 Bitwise Operators C provides six operators for bit manipulation; these may only be applied to
integral operands, that is, char , short , int , and long , whether signed or unsigned. & bitwise AND | bitwise inclusive OR ^ bitwise exclusive OR < < left shift > > right shift ~ one's complement (unary) The bitwise AND operator & is often used to mask off some set of bits,
for example n = n & 0177;...