wcsrtombs(3p) — Linux manual page

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

       wcsnrtombs, wcsrtombs — convert a wide-character string to a
       character string (restartable)

SYNOPSIS

       #include <wchar.h>

       size_t wcsnrtombs(char *restrict dst, const wchar_t **restrict src,
           size_t nwc, size_t len, mbstate_t *restrict ps);
       size_t wcsrtombs(char *restrict dst, const wchar_t **restrict src,
           size_t len, mbstate_t *restrict ps);

DESCRIPTION

       For wcsrtombs(): 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 wcsrtombs() function shall convert a sequence of wide
       characters from the array indirectly pointed to by src into a
       sequence of corresponding characters, beginning in the conversion
       state described by the object pointed to by ps.  If dst is not a
       null pointer, the converted characters shall then be stored into
       the array pointed to by dst.  Conversion continues up to and
       including a terminating null wide character, which shall also be
       stored. Conversion shall stop earlier in the following cases:

        *  When a code is reached that does not correspond to a valid
           character

        *  When the next character would exceed the limit of len total
           bytes to be stored in the array pointed to by dst (and dst is
           not a null pointer)

       Each conversion shall take place as if by a call to the wcrtomb()
       function.

       If dst is not a null pointer, the pointer object pointed to by
       src shall be assigned either a null pointer (if conversion
       stopped due to reaching a terminating null wide character) or the
       address just past the last wide character converted (if any). If
       conversion stopped due to reaching a terminating null wide
       character, the resulting state described shall be the initial
       conversion state.

       If ps is a null pointer, the wcsrtombs() 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 wcsnrtombs() and wcsrtombs() functions need not be thread-
       safe if called with a NULL ps argument.

       The wcsnrtombs() function shall be equivalent to the wcsrtombs()
       function, except that the conversion is limited to the first nwc
       wide characters.

       The wcsrtombs() function shall not change the setting of errno if
       successful.

       The behavior of these functions shall be affected by the LC_CTYPE
       category of the current locale.

       The implementation shall behave as if no function defined in
       System Interfaces volume of POSIX.1‐2017 calls these functions.

RETURN VALUE

       If conversion stops because a code is reached that does not
       correspond to a valid character, an encoding error occurs. In
       this case, these functions shall store the value of the macro
       [EILSEQ] in errno and return (size_t)-1; the conversion state is
       undefined.  Otherwise, these functions shall return the number of
       bytes in the resulting character sequence, not including the
       terminating null (if any).

ERRORS

       These functions shall fail if:

       EILSEQ A wide-character code does not correspond to a valid
              character.

       These functions may fail if:

       EINVAL ps points to an object that contains an invalid conversion
              state.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       mbsinit(3p), wcrtomb(3p)

       The Base Definitions volume of POSIX.1‐2017, wchar.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                     WCSRTOMBS(3P)

Pages that refer to this page: wchar.h(0p), mbsinit(3p), wcrtomb(3p), wcsnrtombs(3p)

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