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] 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.

CONFORMING TO

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 2.79 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.


  Copyright (c) Bruno Haible <haibleclisp.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