mbrlen(3)                  Library Functions Manual                  mbrlen(3)

NAME
       mbrlen - determine number of bytes in next multibyte character

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <wchar.h>

       size_t mbrlen(const char s[restrict .n], size_t n,
                     mbstate_t *restrict ps);

DESCRIPTION
       The mbrlen() function inspects at most n bytes of the multibyte string
       starting at s and extracts the next complete multibyte character.  It
       updates the shift state *ps.  If the multibyte character is not the
       null wide character, it returns the number of bytes that were consumed
       from s.  If the multibyte character is the null wide character, it
       resets the shift state *ps to the initial state and returns 0.

       If the n bytes starting at s do not contain a complete multibyte
       character, mbrlen() returns (size_t) -2.  This can happen even if n >=
       MB_CUR_MAX, if the multibyte string contains redundant shift sequences.

       If the multibyte string starting at s contains an invalid multibyte
       sequence before the next complete character, mbrlen() returns
       (size_t) -1 and sets errno to EILSEQ.  In this case, the effects on *ps
       are undefined.

       If ps is NULL, a static anonymous state known only to the mbrlen()
       function is used instead.

RETURN VALUE
       The mbrlen() function returns the number of bytes parsed from the
       multibyte sequence starting at s, if a non-null wide character was
       recognized.  It returns 0, if a null wide character was recognized.  It
       returns (size_t) -1 and sets errno to EILSEQ, if an invalid multibyte
       sequence was encountered.  It returns (size_t) -2 if it couldn't parse
       a complete multibyte character, meaning that n should be increased.

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

       +--------------------------+---------------+---------------------------+
       |Interface                 | Attribute     | Value                     |
       +--------------------------+---------------+---------------------------+
       |mbrlen ()                 | Thread safety | MT-Unsafe race:mbrlen/!ps |
       +--------------------------+---------------+---------------------------+
STANDARDS
       C11, POSIX.1-2008.

HISTORY
       POSIX.1-2001, C99.

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

SEE ALSO
       mbrtowc(3)

Linux man-pages 6.7               2023-10-31                         mbrlen(3)