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
   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

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