wcrtomb(3p) — Linux manual page


WCRTOMB(3P)             POSIX Programmer's Manual            WCRTOMB(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

NAME         top

       wcrtomb — convert a wide-character code to a character

SYNOPSIS         top

       #include <wchar.h>

       size_t wcrtomb(char *restrict s, wchar_t wc, mbstate_t *restrict ps);

DESCRIPTION         top

       The functionality described on this reference page is aligned
       with the ISO C standard. Any conflict between the requirements
       described here and the ISO C standard is unintentional. This
       volume of POSIX.1‐2017 defers to the ISO C standard.

       If s is a null pointer, the wcrtomb() function shall be
       equivalent to the call:

           wcrtomb(buf, L'\0', ps)

       where buf is an internal buffer.

       If s is not a null pointer, the wcrtomb() function shall
       determine the number of bytes needed to represent the character
       that corresponds to the wide character given by wc (including any
       shift sequences), and store the resulting bytes in the array
       whose first element is pointed to by s.  At most {MB_CUR_MAX}
       bytes are stored. If wc is a null wide character, a null byte
       shall be stored, preceded by any shift sequence needed to restore
       the initial shift state. The resulting state described shall be
       the initial conversion state.

       If ps is a null pointer, the wcrtomb() function shall use its own
       internal mbstate_t object, which is initialized at program start-
       up to the initial conversion state. Otherwise, the mbstate_t
       object pointed to by ps shall be used to completely describe the
       current conversion state of the associated character sequence.
       The implementation shall behave as if no function defined in this
       volume of POSIX.1‐2017 calls wcrtomb().

       The wcrtomb() function need not be thread-safe if called with a
       NULL ps argument.

       The behavior of this function shall be affected by the LC_CTYPE
       category of the current locale.

       The wcrtomb() function shall not change the setting of errno if

RETURN VALUE         top

       The wcrtomb() function shall return the number of bytes stored in
       the array object (including any shift sequences). When wc is not
       a valid wide character, an encoding error shall occur. In this
       case, the function shall store the value of the macro [EILSEQ] in
       errno and shall return (size_t)-1; the conversion state shall be

ERRORS         top

       The wcrtomb() function shall fail if:

       EILSEQ An invalid wide-character code is detected.

       The wcrtomb() function may fail if:

       EINVAL ps points to an object that contains an invalid conversion

       The following sections are informative.

EXAMPLES         top




RATIONALE         top




SEE ALSO         top

       mbsinit(3p), wcsrtombs(3p)

       The Base Definitions volume of POSIX.1‐2017, wchar.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                       WCRTOMB(3P)

Pages that refer to this page: wchar.h(0p)fprintf(3p)fscanf(3p)fwscanf(3p)mbsinit(3p)wcsrtombs(3p)