ungetwc - push back a wide character onto a FILE stream
wint_t ungetwc(wint_t wc, FILE *stream);
() function is the wide-character equivalent of the
(3) function. It pushes back a wide character onto stream
and returns it.
, it returns WEOF
. If wc
is an invalid
wide character, it sets errno
and returns WEOF
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.
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.
() function returns wc
when successful, or WEOF
For an explanation of the terms used in this section, see attributes
POSIX.1-2001, POSIX.1-2008, C99.
The behavior of ungetwc
() depends on the LC_CTYPE
category of the