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3.10 isspace—whitespace character predicate

Synopsis

#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 (0x090x0D, 0x20).


Portability
isspace is ANSI C.

No supporting OS subroutines are required.