NAME
isupper —
upper-case character test
SYNOPSIS
#include
<ctype.h>
int
isupper(int
c);
DESCRIPTION
The
isupper()
function tests for any upper-case letter or any of an implementation-defined
set of characters for which none of
iscntrl(3),
isdigit(3),
ispunct(3), or
isspace(3) is true. In the C locale,
isupper() returns true only for the characters
defined as upper-case letters.
RETURN VALUES
The isupper() function returns zero if the
character tests false or non-zero if the character tests true.
SEE ALSO
isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isxdigit(3), stdio(3), toascii(3), tolower(3), toupper(3), ascii(7)
STANDARDS
The isupper() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
HISTORY
The isupper() function first appeared in
Version 7 AT&T UNIX.
CAVEATS
The argument to isupper() must be
EOF or representable as an unsigned
char; otherwise, the result is undefined.