glibc/stdlib/mbtowc.c
2012-02-09 23:18:22 +00:00

74 lines
2.2 KiB
C

/* Copyright (C) 1991, 1992, 1995-1999, 2002, 2008
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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include <gconv.h>
#include <wcsmbs/wcsmbsload.h>
/* 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.
Attention: this function should NEVER be intentionally used.
The interface is completely stupid. The state is shared between
all conversion functions. You should use instead the restartable
version `mbrtowc'. */
int
mbtowc (wchar_t *pwc, const char *s, size_t n)
{
int result;
static mbstate_t state;
/* If S is NULL the function has to return null or not null
depending on the encoding having a state depending encoding or
not. */
if (s == NULL)
{
const struct gconv_fcts *fcts;
/* Get the conversion functions. */
fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
/* This is an extension in the Unix standard which does not directly
violate ISO C. */
memset (&state, '\0', sizeof state);
result = fcts->towc->__stateful;
}
else if (*s == '\0')
{
if (pwc != NULL)
*pwc = L'\0';
result = 0;
}
else
{
result = __mbrtowc (pwc, s, n, &state);
/* The `mbrtowc' functions tell us more than we need. Fold the -1
and -2 result into -1. */
if (result < 0)
result = -1;
}
return result;
}