mblen

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

NAME
       mblen - determine number of bytes in next multibyte character

SYNOPSIS
       #include <stdlib.h>

       int mblen(const char *s, size_t n);

DESCRIPTION
       If  s is not NULL, the mblen() function inspects at most n bytes of the
       multibyte string starting at s and extracts the next complete multibyte
       character.   It  uses  a static anonymous shift state known only to the
       mblen() function.  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 returns 0.

       If the n bytes starting at s do not contain a complete multibyte  char-
       acter,  mblen()  returns -1.  This can happen even if n is greater than
       or equal to MB_CUR_MAX, if  the  multibyte  string  contains  redundant
       shift sequences.

       If the multibyte string starting at s contains an invalid multibyte se-
       quence before the next complete character, mblen() also returns -1.

       If s is NULL, the mblen() function resets the  shift  state,  known  to
       only  this  function,  to the initial state, and returns nonzero if the
       encoding has nontrivial shift state, or zero if the encoding is  state-
       less.

RETURN VALUE
       The mblen() function returns the number of bytes parsed from the multi-
       byte sequence starting at s, if a non-null wide  character  was  recog-
       nized.   It returns 0, if a null wide character was recognized.  It re-
       turns -1, if an invalid multibyte sequence was  encountered  or  if  it
       couldn't parse a complete multibyte character.

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

       +----------+---------------+----------------+
       |Interface | Attribute     | Value          |
       +----------+---------------+----------------+
       |mblen()   | Thread safety | MT-Unsafe race |
       +----------+---------------+----------------+
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, C99.

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

       The  function  mbrlen(3)  provides a better interface to the same func-
       tionality.

SEE ALSO
       mbrlen(3)

COLOPHON
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       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                          MBLEN(3)