NAME
ungetwc —
un-get wide character from
input stream
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.h>
#include <wchar.h>
wint_t
ungetwc(
wint_t
wc,
FILE *stream);
DESCRIPTION
The
ungetwc() function pushes the wide character
wc (converted to an wchar_t) back onto the input stream
pointed to by
stream. The pushed-backed wide characters
will be returned by subsequent reads on the stream (in reverse order). A
successful intervening call, using the same stream, to one of the file
positioning functions
fseek(3),
fsetpos(3), or
rewind(3) will discard the
pushed back wide characters.
One wide character of push-back is guaranteed, but as long as there is
sufficient memory, an effectively infinite amount of pushback is allowed.
If a character is successfully pushed-back, the end-of-file indicator for the
stream is cleared.
RETURN VALUES
The
ungetwc() function returns the wide character pushed-back
after the conversion, or
WEOF
if the operation fails.
If the value of the argument
c character equals
WEOF
, the operation will fail and the stream will
remain unchanged.
SEE ALSO
fseek(3),
getwc(3)
STANDARDS
The
ungetwc() function conforms to
ISO/IEC
9899:1999 (“ISO C99”).
BUGS
The current implementation uses a fixed sized ungetwc-buffer.