DragonFly On-Line Manual Pages
UNGETWC(3) DragonFly 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 <xlocale.h>
wint_t
ungetwc_l(wint_t wc, FILE *stream, locale_t locale);
DESCRIPTION
The ungetwc() and ungetwc_l() functions push 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.
The ungetwc_l() function takes an explicit locale argument, whereas the
ungetwc() function uses the current global or per-thread locale.
RETURN VALUES
The ungetwc() and ungetwc_l() functions return 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), xlocale(3)
STANDARDS
The ungetwc() function conforms to ISO/IEC 9899:1999 (``ISO C99'').
DragonFly 3.7 December 26, 2013 DragonFly 3.7