glibc/stdlib/mbtowc.c

89 lines
2.2 KiB
C

/* Copyright (C) 1991, 1992, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include "../locale/localeinfo.h"
#include <ctype.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
long int _mb_shift = 0;
/* Convert the multibyte character at S, which is no longer
than N characters, to its `wchar_t' representation, placing
this n *PWC and returning its length. */
int
DEFUN(mbtowc, (pwc, s, n), wchar_t *pwc AND CONST char *s AND size_t n)
{
#if 0
register CONST mb_char *mb;
register wchar_t i;
#endif
if (s == NULL)
return _mb_shift != 0;
if (*s == '\0')
/* ANSI 4.10.7.2, line 19. */
return 0;
if (isascii (*s))
{
/* A normal ASCII character translates to itself. */
if (pwc != NULL)
*pwc = (wchar_t) *s;
return 1;
}
#if 0
if (_ctype_info->mbchar == NULL ||
_ctype_info->mbchar->mb_chars == NULL)
return -1;
if (n > MB_CUR_MAX)
n = MB_CUR_MAX;
for (i = 0; i < WCHAR_MAX; ++i)
{
mb = &_ctype_info->mbchar->mb_chars[i];
/* EOF and NUL aren't MB chars. */
if (i == (wchar_t) EOF || i == (wchar_t) '\0')
continue;
/* Normal ASCII values can't start MB chars. */
else if (isascii(i))
continue;
else if (mb->string == NULL || mb->len == 0)
continue;
else if (mb->len > n)
continue;
else if (!strncmp(mb->string, s, mb->len))
{
_mb_shift += mb->shift;
if (pwc != NULL)
*pwc = i;
return mb->len;
}
}
#endif
return -1;
}