ungetwc — push back a wide character onto a FILE stream
#include <wchar.h>
wint_t ungetwc( |
wint_t | wc, |
FILE * | stream) ; |
The ungetwc
() function is
the wide-character equivalent of the ungetc
() 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.
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Note |
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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.
The behaviour of ungetwc
()
depends on the LC_CTYPE category of the current locale.
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