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/* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org>
*
* GNU Library General Public License (LGPL) version 2 or later.
*
* Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details.
*/
#include "_stdio.h"
/* Function to handle transition to writing.
* Initialize or verify the stream's orientation (even if readonly).
* Check that the stream is writable.
* If currently reading, check that we can transition to writing.
* C99 requires that the stream is at EOF, but attempting to
* auto-transition via fseek() is a configurable option.
* Returns 0 on success and EOF otherwise.
*
* Notes:
* There are two function signatures, depending on wchar support,
* since with no wchar support the orientation is narrow by default.
*/
#ifdef __UCLIBC_HAS_WCHAR__
int __stdio_trans2w_o(FILE * __restrict stream, int oflag)
#else
int __stdio_trans2w(FILE * __restrict stream)
#endif
{
__STDIO_STREAM_VALIDATE(stream);
assert(!__STDIO_STREAM_IS_WRITING(stream));
#ifdef __UCLIBC_HAS_WCHAR__
if (!(stream->__modeflags & oflag)) {
if (stream->__modeflags & (__FLAG_NARROW|__FLAG_WIDE)) {
__UNDEFINED_OR_NONPORTABLE;
goto DO_EBADF;
}
stream->__modeflags |= oflag;
}
#endif
if (stream->__modeflags & __FLAG_READONLY) {
#if defined(__UCLIBC_HAS_WCHAR__) || !defined(__UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION__)
DO_EBADF:
#endif
__set_errno(EBADF);
#ifdef __UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION__
ERROR:
#endif
__STDIO_STREAM_SET_ERROR(stream);
__STDIO_STREAM_VALIDATE(stream);
return EOF;
}
if (__STDIO_STREAM_IS_READING(stream)) {
if (!__FEOF_UNLOCKED(stream)) {
#ifdef __UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION__
/* Need to seek to correct position if we have buffered
* read data or ungots. If appending, we might as well
* seek to the end.
*
* NOTE: If the OS does not handle append files correctly,
* this is insufficient since we would need to seek to
* the end even if not reading.*/
if (((__STDIO_STREAM_BUFFER_RAVAIL(stream))
|| (stream->__modeflags & __FLAG_UNGOT))
&& fseek(stream, 0L,
((stream->__modeflags & __FLAG_APPEND)
? SEEK_END : SEEK_CUR))
) {
/* fseek() only sets error indicator on read/write error. */
goto ERROR;
}
#else
/* C99 requires either at EOF or currently not reading. */
__UNDEFINED_OR_NONPORTABLE;
goto DO_EBADF;
#endif
}
__STDIO_STREAM_CLEAR_READING_AND_UNGOTS(stream);
__STDIO_STREAM_DISABLE_GETC(stream);
/* Reaching EOF does not reset buffer pointers... */
__STDIO_STREAM_INIT_BUFREAD_BUFPOS(stream);
}
__STDIO_STREAM_SET_WRITING(stream);
if (__STDIO_STREAM_IS_NARROW_FBF(stream)) {
__STDIO_STREAM_ENABLE_PUTC(stream);
}
__STDIO_STREAM_VALIDATE(stream);
return 0;
}
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