MBLEN(3)                   Library Functions Manual                   MBLEN(3)

NAME
     mblen, mblen_l - get number of bytes in a character

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <stdlib.h>

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

     #include <stdlib.h>
     #include <xlocale.h>

     int
     mblen_l(const char *s, size_t n, locale_t loc);

DESCRIPTION
     The mblen() function computes the length, in bytes, of a multibyte
     character s, according to the current conversion state.  Up to n bytes
     are examined.

     A call with a null s pointer returns nonzero if the current locale
     requires shift states, zero otherwise.  If shift states are required, the
     shift state is reset to the initial state.

     Although the mblen() function uses the current locale, the mblen_l()
     function may be passed a locale directly. See xlocale(3) for more
     information.

RETURN VALUES
     If s is NULL, the mblen() function returns nonzero if shift states are
     supported, zero otherwise.

     Otherwise, if s is not a null pointer, mblen() either returns 0 if s
     represents the null wide character, or returns the number of bytes
     processed in s, or returns -1 if no multibyte character could be
     recognized or converted.  In this case, mblen()'s internal conversion
     state is undefined.

ERRORS
     The mblen() function will fail if:

     [EILSEQ]           An invalid multibyte sequence was detected.

     [EINVAL]           The internal conversion state is not valid.

SEE ALSO
     mbrlen(3), mbtowc(3), multibyte(3), xlocale(3)

STANDARDS
     The mblen() function conforms to ISO/IEC 9899:1999 ("ISO C99").

macOS 26.6                      April 11, 2004                      macOS 26.6