NAME
isupper —
upper-case character test
LIBRARY
library “libc”
SYNOPSIS
#include
<ctype.h>
int
isupper(int
c);
DESCRIPTION
Theisupper()
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 and returns non-zero if the character tests true.
SEE ALSO
ctype(3), 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”).
CAVEATS
The argument to isupper() must be
EOF or representable as an unsigned
char; otherwise, the behavior is undefined. See the
CAVEATS section of
ctype(3) for more details.