ungetwc

UNGETWC(3)                 Linux Programmer's Manual                UNGETWC(3)

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  fail-
       ure.

ATTRIBUTES
       For  an  explanation  of  the  terms  used  in  this  section,  see at-
       tributes(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  cur-
       rent locale.

SEE ALSO
       fgetwc(3)

COLOPHON
       This  page  is  part of release 5.05 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/.

GNU                               2015-08-08                        UNGETWC(3)