toupper
---translate characters to upper case#include <ctype.h> int toupper(int c); int _toupper(int c);Description
toupper
is a macro which converts lower-case characters to upper
case, leaving all other characters unchanged. It is only defined when
c is an integer in the range EOF
to 255
.
You can use a compiled subroutine instead of the macro definition by
undefining this macro using `#undef toupper
'.
_toupper
performs the same conversion as toupper
, but should
only be used when c is known to be a lowercase character (a
--z
).
Returns
toupper
returns the upper-case equivalent of c when it is a
character between a
and z
, and c otherwise.
_toupper
returns the upper-case equivalent of c when it is a
character between a
and z
. If c is not one of these
characters, the behaviour of _toupper
is undefined.
Portability
toupper
is ANSI C. _toupper
is not recommended for portable programs.
No supporting OS subroutines are required.