ultrix man page for mbrlen

MBRLEN(3)                                                    Linux Programmer's Manual                                                   MBRLEN(3)

NAME
       mbrlen - determine number of bytes in next multibyte character

SYNOPSIS
       #include <wchar.h>

       size_t mbrlen(const char *s, size_t n, mbstate_t *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  con-
       sumed 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 recog-
       nized.  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 |
       +----------+---------------+---------------------------+
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, C99.

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

SEE ALSO
       mbrtowc(3)

COLOPHON
       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU                                                                 2015-08-08                                                           MBRLEN(3)