ungetwc - push wide character back onto input stream

Syntax

#include <wchar.h> Optional #include <stdio.h> (End) wint_t ungetwc(wint_t wc, FILE *stream);

Description ungetwc() pushes the character corresponding to the wide character code wc back onto

	the input stream pointed to by stream. The pushed-back characters will be returned by subsequent reads on that stream in reverse order. A successful intervening call to a filepositioning function (fseek(), fsetpos() or rewind()) for the same data stream deletes the pushed-back characters for the stream. The external storage associated with the data stream remains unchanged. One byte of pushback is guaranteed. If ungetwc() is called too many times on the same stream without an intervening read or file-positioning operation on that stream, the pushback operation may fail. If the value of wc is equal to the macro WEOF, the operation will fail and the input stream will remain unchanged. A successful call to ungetwc() clears 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 bytes will be the same as it was before the bytes were pushed back. The file-position indicator is decremented by each successful call to ungetwc(); if its value was 0 before a call, its value will be indeterminate after the call. Restriction This version of the C runtime system only supports 1-byte characters as wide character codes. They are of type wchar_t (see stddef.h). (End)
Return val.	Pushed back wide character
		upon successful completion.
	WEOF	if the wide character could not be pushed back. errno is set to indicate the error.
Errors	ungetwc() will fail if: Extension EINVAL     An attempt was made to access a BS2000 file.
See also	fseek(), fsetpos(), read(), rewind(), setbuf(), stdio.h, wchar.h.