mbrlen(3p) — Linux manual page


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

       mbrlen — get number of bytes in a character (restartable)

SYNOPSIS         top

       #include <wchar.h>

       size_t mbrlen(const char *restrict s, size_t n,
           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.1‐2008 defers to the ISO C standard.

       If s is not a null pointer, mbrlen() shall determine the number of
       bytes constituting the character pointed to by s.  It shall be
       equivalent to:

           mbstate_t internal;
           mbrtowc(NULL, s, n, ps != NULL ? ps : &internal);

       If ps is a null pointer, the mbrlen() 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.1‐2008 calls mbrlen().

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

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

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

RETURN VALUE         top

       The mbrlen() function shall return the first of the following that

       0           If the next n or fewer bytes complete the character that
                   corresponds to the null wide character.

       positive    If the next n or fewer bytes complete a valid character;
                   the value returned shall be the number of bytes that
                   complete the character.

       (size_t)−2  If the next n bytes contribute to an incomplete but
                   potentially valid character, and all n bytes have been
                   processed. When n has at least the value of the
                   {MB_CUR_MAX} macro, this case can only occur if s points
                   at a sequence of redundant shift sequences (for
                   implementations with state-dependent encodings).

       (size_t)−1  If an encoding error occurs, in which case the next n or
                   fewer bytes do not contribute to a complete and valid
                   character. In this case, [EILSEQ] shall be stored in
                   errno and the conversion state is undefined.

ERRORS         top

       The mbrlen() function shall fail if:

       EILSEQ An invalid character sequence is detected.

       The mbrlen() 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), mbrtowc(3p)

       The Base Definitions volume of POSIX.1‐2008, wchar.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/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                 2013                          MBRLEN(3P)

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