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)