126 lines
3.7 KiB
C
126 lines
3.7 KiB
C
/****************************************************************************
|
|
* libs/libc/stdio/lib_ungetwc.c
|
|
*
|
|
* Copyright © 2005-2014 Rich Felker, et al.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining
|
|
* a copy of this software and associated documentation files (the
|
|
* "Software"), to deal in the Software without restriction, including
|
|
* without limitation the rights to use, copy, modify, merge, publish,
|
|
* distribute, sublicense, and/or sell copies of the Software, and to
|
|
* permit persons to whom the Software is furnished to do so, subject to
|
|
* the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be
|
|
* included in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
|
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
|
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
|
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <wchar.h>
|
|
#include <limits.h>
|
|
#include <ctype.h>
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
|
|
#ifdef CONFIG_FILE_STREAM
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: ungetwc_unlocked
|
|
*
|
|
* Description:
|
|
* Put a wide character back to the stream without lock the stream
|
|
*
|
|
* Input Parameters:
|
|
* wc - the wide character to be put back
|
|
* f - the file stream to put the wide character back to
|
|
*
|
|
* Returned Value:
|
|
* Return the wide character that put back to the stream on success,
|
|
* return WEOF on failed, and keep the given stream remains unchanged.
|
|
*
|
|
****************************************************************************/
|
|
|
|
wint_t ungetwc_unlocked(wint_t wc, FAR FILE *f)
|
|
{
|
|
char mbc[MB_LEN_MAX];
|
|
int l = 1;
|
|
|
|
/* Stream must be open for read access */
|
|
|
|
if ((f->fs_oflags & O_RDOK) == 0)
|
|
{
|
|
return WEOF;
|
|
}
|
|
|
|
/* Try conversion early so we can fail without locking if invalid */
|
|
|
|
if ((l = wctomb(mbc, wc)) <= 0)
|
|
{
|
|
return WEOF;
|
|
}
|
|
|
|
#if CONFIG_NUNGET_CHARS > 0
|
|
if (f->fs_nungotten + l <= CONFIG_NUNGET_CHARS)
|
|
{
|
|
memcpy(f->fs_ungotten + f->fs_nungotten, mbc, l);
|
|
f->fs_nungotten += l;
|
|
return wc;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
return WEOF;
|
|
}
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ungetwc
|
|
*
|
|
* Description:
|
|
* Put a wide character back to the stream
|
|
*
|
|
* Input Parameters:
|
|
* wc - the wide character that need to put back to the stream
|
|
* f - pointer to a FILE object that identifies an input stream
|
|
*
|
|
* Returned Value:
|
|
* Return the wide character that put back to the stream on success,
|
|
* return WEOF on failed, and keep the given stream remains unchanged.
|
|
*
|
|
****************************************************************************/
|
|
|
|
wint_t ungetwc(wint_t wc, FAR FILE *f)
|
|
{
|
|
wint_t ret;
|
|
|
|
/* Verify that a non-NULL stream was provided and wc is not WEOF */
|
|
|
|
if (!f || wc == WEOF)
|
|
{
|
|
return WEOF;
|
|
}
|
|
|
|
flockfile(f);
|
|
ret = ungetwc_unlocked(wc, f);
|
|
funlockfile(f);
|
|
return ret;
|
|
}
|
|
|
|
#endif /* CONFIG_FILE_STREAM */
|