libc/stdio/fwide.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include "_stdio.h"
   9
  10 /* TODO: According to SUSv3 should return EBADF if invalid stream. */
  11
  12 int fwide(register FILE *stream, int mode)
  13 {
  14         __STDIO_AUTO_THREADLOCK_VAR;
  15
  16         __STDIO_AUTO_THREADLOCK(stream);
  17
  18         __STDIO_STREAM_VALIDATE(stream);
  19
  20         if (mode && !(stream->__modeflags & (__FLAG_WIDE|__FLAG_NARROW))) {
  21                 stream->__modeflags |= ((mode > 0) ? __FLAG_WIDE : __FLAG_NARROW);
  22         }
  23
  24         mode = (stream->__modeflags & __FLAG_WIDE)
  25                 - (stream->__modeflags & __FLAG_NARROW);
  26
  27         assert((stream->__modeflags & (__FLAG_WIDE|__FLAG_NARROW))
  28                    != (__FLAG_WIDE|__FLAG_NARROW));
  29         __STDIO_AUTO_THREADUNLOCK(stream);
  30
  31         return mode;
  32 }