/* 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) { DO_EBADF: __set_errno(EBADF); ERROR: __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; }