glibc/wcsmbs/wcsnrtombs.c

140 lines
3.8 KiB
C

/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <gconv.h>
#include <wchar.h>
#include <wcsmbsload.h>
#include <assert.h>
#ifndef EILSEQ
# define EILSEQ EINVAL
#endif
/* This is the private state used if PS is NULL. */
static mbstate_t state;
/* This is a non-standard function but it is very useful in the
implementation of stdio because we have to deal with unterminated
buffers. At most NWC wide character will be converted. */
size_t
__wcsnrtombs (dst, src, nwc, len, ps)
char *dst;
const wchar_t **src;
size_t nwc;
size_t len;
mbstate_t *ps;
{
struct gconv_step_data data;
const wchar_t *srcend;
int status;
size_t result;
/* Tell where we want the result. */
data.invocation_counter = 0;
data.internal_use = 1;
data.is_last = 1;
data.statep = ps ?: &state;
if (nwc == 0)
return 0;
srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
/* Make sure we use the correct function. */
update_conversion_ptrs ();
/* We have to handle DST == NULL special. */
if (dst == NULL)
{
char buf[256]; /* Just an arbitrary value. */
const wchar_t *inbuf = *src;
size_t dummy;
result = 0;
data.outbufend = buf + sizeof (buf);
do
{
data.outbuf = buf;
status = (*__wcsmbs_gconv_fcts.tomb->fct) (__wcsmbs_gconv_fcts.tomb,
&data,
(const char **) &inbuf,
(const char *) srcend,
&dummy, 0);
/* Count the number of bytes. */
result += data.outbuf - buf;
}
while (status == GCONV_FULL_OUTPUT);
if ((status == GCONV_OK || status == GCONV_EMPTY_INPUT)
&& data.outbuf[-1] == '\0')
/* Don't count the NUL character in. */
--result;
}
else
{
/* This code is based on the safe assumption that all internal
multi-byte encodings use the NUL byte only to mark the end
of the string. */
size_t dummy;
data.outbuf = dst;
data.outbufend = dst + len;
status = (*__wcsmbs_gconv_fcts.tomb->fct) (__wcsmbs_gconv_fcts.tomb,
&data, (const char **) src,
(const char *) srcend,
&dummy, 0);
/* Count the number of bytes. */
result = data.outbuf - dst;
/* We have to determine whether the last character converted
is the NUL character. */
if ((status == GCONV_OK || status == GCONV_EMPTY_INPUT)
&& data.outbuf[-1] == '\0')
{
assert (data.outbuf != dst);
assert (__mbsinit (data.statep));
*src = NULL;
--result;
}
}
/* There must not be any problems with the conversion but illegal input
characters. */
assert (status == GCONV_OK || status == GCONV_EMPTY_INPUT
|| status == GCONV_ILLEGAL_INPUT
|| status == GCONV_INCOMPLETE_INPUT || status == GCONV_FULL_OUTPUT);
if (status != GCONV_OK && status != GCONV_FULL_OUTPUT
&& status != GCONV_EMPTY_INPUT)
{
result = (size_t) -1;
__set_errno (EILSEQ);
}
return result;
}
weak_alias (__wcsnrtombs, wcsnrtombs)