SYNOPSIS

     #include <wchar.h>

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

     #include <xlocale.h>

     size_t
     mbrlen_l(const char * restrict s, size_t n, mbstate_t * restrict ps,
         locale_t loc);

DESCRIPTION

     The mbrlen() function inspects at most n bytes pointed to by s to deter-
     mine the number of bytes needed to complete the next multibyte character.

     The mbstate_t argument, ps, is used to keep track of the shift state.  If
     it is NULL, mbrlen() uses an internal, static mbstate_t object, which is
     initialized to the initial conversion state at program startup.

     It is equivalent to:

           mbrtowc(NULL, s, n, ps);

     Except that when ps is a NULL pointer, mbrlen() uses its own static,
     internal mbstate_t object to keep track of the shift state.

     While the mbrlen() function uses the current locale, the mbrlen_l() func-
     tion may be passed a locale directly. See xlocale(3) for more informa-
     tion.

RETURN VALUES

     The mbrlen() functions returns:

     0       The next n or fewer bytes represent the null wide character
             (L'\0').

     >0      The next n or fewer bytes represent a valid character, mbrlen()
             returns the number of bytes used to complete the multibyte char-
             acter.

     (size_t)-2
             The next n contribute to, but do not complete, a valid multibyte
             character sequence, and all n bytes have been processed.

     (size_t)-1
             An encoding error has occurred.  The next n or fewer bytes do not
             contribute to a valid multibyte character.

EXAMPLES

     A function that calculates the number of characters in a multibyte char-
                   }

                   return (chars);
           }

ERRORS

     The mbrlen() function will fail if:

     [EILSEQ]           An invalid multibyte sequence was detected.

     [EINVAL]           The conversion state is invalid.

SEE ALSO

     mblen(3), mbrtowc(3), multibyte(3), xlocale(3)

STANDARDS

     The mbrlen() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

BSD                              April 7, 2004                             BSD