NAME
isupper —
upper-case character
test
LIBRARY
Standard C Library (libc, -lc)
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 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.