/*
FUNCTION
<<tolower>>---translate characters to lower case
INDEX
tolower
INDEX
_tolower
ANSI_SYNOPSIS
#include <ctype.h>
int tolower(int <[c]>);
int _tolower(int <[c]>);
TRAD_SYNOPSIS
#include <ctype.h>
int tolower(<[c]>);
int _tolower(<[c]>);
DESCRIPTION
<<tolower>> is a macro which converts upper-case characters to lower
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 tolower>>'.
<<_tolower>> performs the same conversion as <<tolower>>, but should
only be used when <[c]> is known to be an uppercase character (<<A>>--<<Z>>).
RETURNS
<<tolower>> returns the lower-case equivalent of <[c]> when it is a
character between <<A>> and <<Z>>, and <[c]> otherwise.
<<_tolower>> returns the lower-case equivalent of <[c]> when it is a
character between <<A>> and <<Z>>. If <[c]> is not one of these
characters, the behaviour of <<_tolower>> is undefined.
PORTABILITY
<<tolower>> is ANSI C. <<_tolower>> is not recommended for portable
programs.
No supporting OS subroutines are required.
*/
#include <_ansi.h>
#include <ctype.h>
#undef tolower
int
_DEFUN(tolower,(c),int c)
{
return isupper(c) ? (c) - 'A' + 'a' : c;
}