Guardian C Library Calls Reference Manual
Reference to Library Calls
Guardian TNS C Library Calls Reference Manual—128833 3-99
isspace
isspace
The isspace function tests whether its argument is a space character (a blank, tab, or
newline).
character
specifies the character to test.
Return Value
is nonzero if character is a space character (a blank, horizontal or vertical tab, or
newline); otherwise, isspace returns the value zero.
Usage Guidelines
•
The character-testing routine isspace is implemented as a macro, but the C compiler
provides an underlying function with the same name as the macro. Although the
macro is faster than the function, it evaluates its argument more than once.
Consequently, if you need to provide an expression with side effects as the argument
to this routine, you should undefine the macro so that the C compiler uses the
function instead. For more information about undefining macros, refer to the C/C++
Programmer’s Guide.
#include <ctypeh>
int isspace(int character);