wctomb(3p) — Linux manual page

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

PROLOG

       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

       wctomb — convert a wide-character code to a character

SYNOPSIS

       #include <stdlib.h>

       int wctomb(char *s, wchar_t wchar);

DESCRIPTION

       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.

       The wctomb() function shall determine the number of bytes needed
       to represent the character corresponding to the wide-character
       code whose value is wchar (including any change in the shift
       state). It shall store the character representation (possibly
       multiple bytes and any special bytes to change shift state) in
       the array object pointed to by s (if s is not a null pointer). At
       most {MB_CUR_MAX} bytes shall be stored. If wchar is 0, a null
       byte shall be stored, preceded by any shift sequence needed to
       restore the initial shift state, and wctomb() shall be left in
       the initial shift state.

       The behavior of this function is affected by the LC_CTYPE
       category of the current locale. For a state-dependent encoding,
       this function shall be placed into its initial state by a call
       for which its character pointer argument, s, is a null pointer.
       Subsequent calls with s as other than a null pointer shall cause
       the internal state of the function to be altered as necessary. A
       call with s as a null pointer shall cause this function to return
       a non-zero value if encodings have state dependency, and 0
       otherwise. Changing the LC_CTYPE category causes the shift state
       of this function to be unspecified.

       The wctomb() function need not be thread-safe.

       The implementation shall behave as if no function defined in this
       volume of POSIX.1‐2017 calls wctomb().

RETURN VALUE

       If s is a null pointer, wctomb() shall return a non-zero or 0
       value, if character encodings, respectively, do or do not have
       state-dependent encodings. If s is not a null pointer, wctomb()
       shall return -1 if the value of wchar does not correspond to a
       valid character, or return the number of bytes that constitute
       the character corresponding to the value of wchar.

       In no case shall the value returned be greater than the value of
       the {MB_CUR_MAX} macro.

ERRORS

       The wctomb() function shall fail if:

       EILSEQ An invalid wide-character code is detected.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       mblen(3p), mbtowc(3p), mbstowcs(3p), wcstombs(3p)

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

COPYRIGHT

       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                        WCTOMB(3P)

Pages that refer to this page: ctype.h(0p), stdlib.h(0p), mblen(3p), mbstowcs(3p), mbtowc(3p), setlocale(3p), wcstombs(3p)

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