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/*
FUNCTION
<<tolower>>, <<tolower_l>>---translate characters to lowercase
INDEX
tolower
INDEX
tolower_l
INDEX
_tolower
SYNOPSIS
#include <ctype.h>
int tolower(int <[c]>);
int _tolower(int <[c]>);
#include <ctype.h>
int tolower_l(int <[c]>, locale_t <[locale]>);
DESCRIPTION
<<tolower>> is a macro which converts uppercase characters to lowercase,
leaving all other characters unchanged. It is only defined when
<[c]> is an integer in the range <<EOF>> to <<255>>.
<<tolower_l>> is like <<tolower>> but performs the function based on the
locale specified by the locale object locale. If <[locale]> is
LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.
You can use a compiled subroutine instead of the macro definition by
undefining this macro using `<<#undef tolower>>' or `<<#undef tolower_l>>'.
<<_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>>, <<tolower_l>> return the lowercase equivalent of <[c]> when
<[c]> is an uppercase character, and <[c]> otherwise.
<<_tolower>> returns the lowercase 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.
<<tolower_l>> is POSIX-1.2008.
No supporting OS subroutines are required.
*/
#include <_ansi.h>
#include <ctype.h>
#if defined (_MB_EXTENDED_CHARSETS_ISO) || defined (_MB_EXTENDED_CHARSETS_WINDOWS)
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <wctype.h>
#include <wchar.h>
#endif
#undef tolower
int
tolower (int c)
{
#if defined (_MB_EXTENDED_CHARSETS_ISO) || defined (_MB_EXTENDED_CHARSETS_WINDOWS)
if ((unsigned char) c <= 0x7f)
return isupper (c) ? c - 'A' + 'a' : c;
else if (c != EOF && MB_CUR_MAX == 1 && isupper (c))
{
char s[MB_LEN_MAX] = { c, '\0' };
wchar_t wc;
if (mbtowc (&wc, s, 1) >= 0
&& wctomb (s, (wchar_t) towlower ((wint_t) wc)) == 1)
c = (unsigned char) s[0];
}
return c;
#else
return isupper(c) ? (c) - 'A' + 'a' : c;
#endif
}
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