SETBIT(9) BSD Kernel Developer's Manual SETBIT(9)
NAME
setbit -- macros related to bitmaps
SYNOPSIS
#include <sys/param.h>
void
setbit(array, x);
void
clrbit(array, x);
int
isset(array, x);
int
isclr(array, x);
DESCRIPTION
The setbit family of macros operate with bitmaps, also known as bit arrays.
In a nutshell, setbit() sets the bit x in array, clrbit() clears it, isset() tests whether x is set, and isclr() returns 1 if x is not set.
EXAMPLES
The following example declares a buffer of 10 chars, treating it as an array of 80 bits:
char buf[10];
...
setbit(buf, 12); /* set the fifth bit in the second byte */
SEE ALSO
bitstring(3)
CAVEATS
The number of valid bits in a given array is assumed to be multiple of CHAR_BIT, the number of bits for smallest object that is not a bit-
field.
BSD
March 1, 2010 BSD
