toupper
[translate characters to upper case]
SYNOPSIS
#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 uppercase 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.
COMPLIANCE
toupper
is ANSI C. _toupper
is not recommended for portable programs.
No supporting OS subroutines are required.
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