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 uppercase
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).
COMPLIANCE
isupper
is ANSI C.
No supporting OS subroutines are required.
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