isspace---whitespace character predicate#include <ctype.h> int isspace(int c);Description
isspace is a macro which classifies ASCII integer values by table
lookup. It is a predicate returning non-zero for whitespace
characters, and 0 for other characters. It is defined only when isascii(c) is true or c is EOF.
You can use a compiled subroutine instead of the macro definition by
undefining the macro using `#undef isspace'.
Returns
isspace returns non-zero if c is a space, tab, carriage return, new
line, vertical tab, or formfeed (0x09--0x0D, 0x20).
Portability
isspace is ANSI C.
No supporting OS subroutines are required.