UNGETWC(3) BSD Library Functions Manual UNGETWC(3)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 infor‐
mation.
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 ALSOfseek(3), getwc(3), xlocale(3)STANDARDS
The ungetwc() function conforms to ISO/IEC 9899:1999 (“ISO C99”).
BSD March 3, 2004 BSD
