Documentation Archive Developer
ADC Home > Reference Library > Reference > Mac OS X > Mac OS X Man Pages


This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles.

For more information about the manual page format, see the manual page for manpages(5).

UNGETWC(3)               BSD Library Functions Manual               UNGETWC(3)

     ungetwc, ungetwc_l -- un-get wide character from input stream

     Standard C Library (libc, -lc)

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

     ungetwc(wint_t wc, FILE *stream);

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

     ungetwc_l(wint_t wc, FILE *stream, locale_t loc);

     The ungetwc() function pushes the wide character wc (converted to an
     wchar_t) back onto the input stream pointed to by stream.  The pushed-backed pushedbacked
     backed wide characters will be returned (in reverse order) by subsequent
     reads on the stream.  A successful intervening call to one of the file
     positioning functions fseek(3), fsetpos(3), or rewind(3), using the same
     stream, will discard the pushed-back wide characters.

     Only one wide character of push-back is guaranteed, but as long as there
     is sufficient memory, an effectively infinite amount of push-back is

     If a character is successfully pushed-back, the end-of-file indicator for
     the stream is cleared.

     Although the ungetwc() function uses the current locale, the ungetwc_l()
     function may be passed a locale directly. See xlocale(3) for more infor-mation. information.

     The ungetwc() function returns the wide character pushed-back after the
     conversion, or WEOF if the operation fails.  If the value of the argument
     c character equals WEOF, the operation will fail and the stream will
     remain unchanged.

     fseek(3), getwc(3), xlocale(3)

     The ungetwc() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

BSD                              March 3, 2004                             BSD