ungetwc(3) — Linux manual page

UNGETWC(3)              Linux Programmer's Manual             UNGETWC(3)

NAME         top

       ungetwc - push back a wide character onto a FILE stream

SYNOPSIS         top

       #include <wchar.h>

       wint_t ungetwc(wint_t wc, FILE *stream);

DESCRIPTION         top

       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         top

       The ungetwc() function returns wc when successful, or WEOF upon
       failure.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │Interface                             │ Attribute     │ Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │ungetwc()                             │ Thread safety │ MT-Safe │
       └──────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO         top

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

NOTES         top

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

SEE ALSO         top

       fgetwc(3)

COLOPHON         top

       This page is part of release 5.13 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/.

GNU                            2021-03-22                     UNGETWC(3)

Pages that refer to this page: fgetc(3),  fgetwc(3),  gets(3)

Copyright and license for this manual page

HTML rendering created 2022-12-18 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.