Name
ungetwc - push back a wide character onto a FILE streamLibrary
Standard C library ( libc ", " -lc )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 |
| T} | Thread safety | MT-Safe |
Standards
C11, POSIX.1-2008.History
POSIX.1-2001, C99.Notes
The behavior of ungetwc() depends on the LC_CTYPE category of the current locale.See Also
- fgetwc(3)