isblank—blank character predicate #include <ctype.h>
int isblank(int c);
Description
isblank is a function which classifies ASCII integer values by table
lookup. It is a predicate returning non-zero for blank characters, and 0
for other characters. It is defined only if c is representable as an
unsigned char or if c is EOF.
Returns
isblank returns non-zero if c is a blank character.
Portability
isblank is C99.
No supporting OS subroutines are required.