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UNGETWC(P)			    POSIX Programmer's Manual			       UNGETWC(P)

       ungetwc - push wide-character code back into the input stream

       #include <stdio.h>
       #include <wchar.h>

       wint_t ungetwc(wint_t wc, FILE *stream);

       The  ungetwc()  function shall push the character corresponding to the wide-character code
       specified by wc back onto the input stream pointed to by stream. The  pushed-back  charac-
       ters  shall  be	returned by subsequent reads on that stream in the reverse order of their
       pushing. A successful intervening call (with the stream pointed to by stream) to  a  file-
       positioning  function  ( fseek(), fsetpos(), or rewind()) discards any pushed-back charac-
       ters for the stream. The external storage corresponding to the stream is unchanged.

       At least one character of push-back shall be provided. If ungetwc()  is	called	too  many
       times on the same stream without an intervening read or file-positioning operation on that
       stream, the operation may fail.

       If the value of wc equals that of the macro WEOF, the operation shall fail and  the  input
       stream shall be left unchanged.

       A  successful  call to ungetwc() shall clear the end-of-file indicator for the stream. The
       value of the file-position indicator for  the  stream  after  reading  or  discarding  all
       pushed-back characters shall be the same as it was before the characters were pushed back.
       The file-position indicator is decremented (by one or more) by  each  successful  call  to
       ungetwc(); if its value was 0 before a call, its value is unspecified after the call.

       Upon  successful  completion, ungetwc() shall return the wide-character code corresponding
       to the pushed-back character.  Otherwise, it shall return WEOF.

       The ungetwc() function may fail if:

       EILSEQ An invalid character sequence is detected, or a wide-character code does not corre-
	      spond to a valid character.

       The following sections are informative.





       fseek()	,  fsetpos()  ,  read()  ,  rewind()  , setbuf() , the Base Definitions volume of
       IEEE Std 1003.1-2001, <stdio.h>, <wchar.h>

       Portions of this text are reprinted and	reproduced  in	electronic  form  from	IEEE  Std
       1003.1,	2003  Edition,	Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard, the original IEEE and The Open Group Standard is the referee document. The orig-
       inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group			       2003				       UNGETWC(P)
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