NAME
isupper
- upper-case character test
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
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
otherwise, the behavior is undefined.
See the
CAVEATS
section of
ctype(3)
for more details.