UNGETWC
Section: Linux Programmer's Manual (3)
Updated: 2015-08-08
Page Index
NAME
ungetwc - push back a wide character onto a FILE stream
SYNOPSIS
#include <wchar.h>
wint_t ungetwc(wint_t wc, FILE *stream);
DESCRIPTION
The
ungetwc()
function is the wide-character equivalent of the
ungetc(3)
function.
It pushes back a wide character onto
stream
and returns it.
If
wc
is
WEOF,
it returns
WEOF.
If
wc
is an invalid wide character,
it sets
errno
to
EILSEQ
and returns
WEOF.
If
wc
is a valid wide character, it is pushed back onto the stream
and thus becomes available for future wide-character read operations.
The file-position indicator is decremented by one or more.
The end-of-file
indicator is cleared.
The backing storage of the file is not affected.
Note:
wc
need not be the last wide-character read from the stream;
it can be any other valid wide character.
If the implementation supports multiple push-back operations in a row, the
pushed-back wide characters will be read in reverse order; however, only one
level of push-back is guaranteed.
RETURN VALUE
The
ungetwc()
function returns
wc
when successful, or
WEOF
upon
failure.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
ungetwc()
| Thread safety | MT-Safe
|
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.
NOTES
The behavior of
ungetwc()
depends on the
LC_CTYPE
category of the
current locale.
SEE ALSO
fgetwc(3)
COLOPHON
This page is part of release 5.10 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.