mblen(3) — Linux manual page


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

NAME         top

       mblen - determine number of bytes in next multibyte character

SYNOPSIS         top

       #include <stdlib.h>

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

DESCRIPTION         top

       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
       character, 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
       sequence 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

RETURN VALUE         top

       The mblen() 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 -1, if an invalid multibyte sequence was encountered or if
       it couldn't parse a complete multibyte character.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface Attribute     Value          │
       │mblen()   │ Thread safety │ MT-Unsafe race │

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008, C99.

NOTES         top

       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

SEE ALSO         top


COLOPHON         top

       This page is part of release 5.08 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

GNU                              2015-08-08                         MBLEN(3)

Pages that refer to this page: mb_cur_max(3)MB_CUR_MAX(3)mbstowcs(3)mbtowc(3)wcstombs(3)wctomb(3)locale(7)