isupper---uppercase character predicate

Synopsis

#include <ctype.h>
int isupper(int c);

Description
isupper is a macro which classifies ASCII integer values by table lookup. It is a predicate returning non-zero for upper-case letters (A--Z), 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 isupper'.

Returns
isupper returns non-zero if c is a upper case letter (A-Z).

Portability
isupper is ANSI C.

No supporting OS subroutines are required.

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