1 /* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org>
3 * GNU Library General Public License (LGPL) version 2 or later.
5 * Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details.
10 /* Note: This is the application-callable ungetwc. If wscanf calls this, it
11 * should also set stream->__ungot[1] to 0 if this is the only ungot, as well
12 * as reset stream->__ungot_width[1] for use by _stdio_adjpos().
15 wint_t ungetwc(wint_t c
, register FILE *stream
)
17 __STDIO_AUTO_THREADLOCK_VAR
;
19 __STDIO_AUTO_THREADLOCK(stream
);
20 __STDIO_STREAM_VALIDATE(stream
); /* debugging only */
22 /* Note: Even if c == WEOF, we need to initialize/verify the
23 * stream's orientation and ensure the stream is in reading
24 * mode (if readable and properly oriented). */
25 if ((!__STDIO_STREAM_IS_WIDE_READING(stream
)
26 && __STDIO_STREAM_TRANS_TO_READ(stream
, __FLAG_WIDE
))
27 || ((stream
->__modeflags
& __FLAG_UNGOT
)
28 && ((stream
->__modeflags
& 1) || stream
->__ungot
[1]))
33 /* In the wide case, getc macros should already be disabled. */
34 /* __STDIO_STREAM_DISABLE_GETC(stream); */
36 /* Flag this as a user ungot, as scanf does the necessary fixup. */
37 stream
->__ungot
[1] = 1;
38 stream
->__ungot
[(++stream
->__modeflags
) & 1] = c
;
39 /* Note: ungot_width is handled by fgetwc. */
41 __STDIO_STREAM_CLEAR_EOF(stream
); /* Must clear end-of-file flag. */
44 __STDIO_STREAM_VALIDATE(stream
);
45 __STDIO_AUTO_THREADUNLOCK(stream
);
49 libc_hidden_def(ungetwc
)