tolower
[translate characters to lower case]
SYNOPSIS
#include
<ctype.h>
int tolower(int
c);
int _tolower(int
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.
COMPLIANCE
tolower
is ANSI C. _tolower
is not recommended for portable programs.
No supporting OS subroutines are required.
0