NAME
ungetwc, ungetwc_l
— 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);
#include <stdio.h>
#include <wchar.h>
#include <xlocale.h>
wint_t
ungetwc_l(wint_t wc,
FILE *stream, locale_t loc);
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 (in reverse order) by subsequent reads on the stream. A successful
intervening call to one of the file positioning functions
fseek(3),
fsetpos(3), or rewind(3), using the same stream, will discard the
pushed-back wide characters.
Only one wide character of push-back is guaranteed, but as long as there is sufficient memory, an effectively infinite amount of push-back is allowed.
If a character is successfully pushed-back, the end-of-file indicator for the stream is cleared.
Although the
ungetwc()
function uses the current locale, the
ungetwc_l()
function may be passed a locale directly. See
xlocale(3) for more information.
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
STANDARDS
The ungetwc() function conforms to
ISO/IEC 9899:1999
(“ISO C99”).