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MBRLEN(3)	       FreeBSD Library Functions Manual		     MBRLEN(3)

NAME
     mbrlen -- get number of bytes in a	character (restartable)

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <wchar.h>

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

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.

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-
     acter string:

	   size_t
	   nchars(const	char *s)
	   {
		   size_t charlen, chars;
		   mbstate_t mbs;

		   chars = 0;
		   memset(&mbs,	0, sizeof(mbs));
		   while ((charlen = mbrlen(s, MB_CUR_MAX, &mbs)) != 0 &&
		       charlen != (size_t)-1 &&	charlen	!= (size_t)-2) {
			   s +=	charlen;
			   chars++;
		   }

		   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)

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

FreeBSD	10.1			 April 7, 2004			  FreeBSD 10.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | EXAMPLES | ERRORS | SEE ALSO | STANDARDS

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