NAME

       ungetwc - push back a wide character onto a FILE stream

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   │
       ├──────────┼───────────────┼─────────┤
       │ungetwc() │ Thread safety │ MT-Safe │
       └──────────┴───────────────┴─────────┘

CONFORMING TO

       POSIX.1-2001, POSIX.1-2008, C99.

NOTES

       The behavior of ungetwc() depends on the LC_CTYPE category of the current locale.

SEE ALSO

       fgetwc(3)

COLOPHON

       This  page  is  part  of  release  5.10  of  the  Linux man-pages project.  A description of the project,
       information  about  reporting  bugs,  and  the  latest  version  of  this   page,   can   be   found   at
       https://www.kernel.org/doc/man-pages/.