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() 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]](../stylesheet/note.png) |
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.
NOTES
The behaviour of ungetwc()
depends on the LC_CTYPE category of the current locale.
SEE ALSO
fgetwc(3)
Copyright (c) Bruno Haible <haible@clisp.cons.org>
This is free documentation; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
References consulted:
GNU glibc-2 source code and manual
Dinkumware C library reference http://www.dinkumware.com/
OpenGroup's Single Unix specification http://www.UNIX-systems.org/online.html
ISO/IEC 9899:1999
|
