#include <ctype.h>
int isupper(int c);
The isupper() function
tests for any character that is an uppercase letter or is one of
an implementation-defined set of characters for which none of
iscntrl(), isdigit(),
ispunct(), or isspace() is true.
In the C locale, isupper()
returns true only for the characters defined as uppercase letters.
The behavior of the isupper()
function is affected by the current locale. To modify the
behavior, change the LC_CTYPE category in
setlocale(), that is,
setlocale(LC_CTYPE, newlocale). In the C locale
or in a locale where character type information is not defined,
characters are classified according to the rules of the U.S.
ASCII 7-bit coded character set.
- c
-
Is an integer whose value is representable as an unsigned char,
or the value of the macro EOF.
The isupper() function
returns non-zero for true and zero for false. If the parameter is
not in the domain of the function, the return result is undefined.
ANSI/ISO 9899-1990.
MT-Safe, with exceptions.
This function is MT-Safe as long as no thread calls setlocale() while
this function is executing.
None.
MKS Toolkit for Professional Developers
MKS Toolkit for Enterprise Developers
MKS Toolkit for Enterprise Developers 64-Bit Edition
- Functions:
- isalnum(), isalpha(), isascii(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isxdigit(), setlocale()
MKS Toolkit 9.2 Documentation Build 16.