MULTIBYTE(3)						   BSD Library Functions Manual 					      MULTIBYTE(3)

NAME

     multibyte -- multibyte and wide character manipulation functions

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <limits.h>
     #include <stdlib.h>
     #include <wchar.h>

DESCRIPTION

     The basic elements of some written natural languages, such as Chinese, cannot be represented uniquely with single C chars.  The C standard
     supports two different ways of dealing with extended natural language encodings: wide characters and multibyte characters.  Wide characters
     are an internal representation which allows each basic element to map to a single object of type wchar_t.	Multibyte characters are used for
     input and output and code each basic element as a sequence of C chars.  Individual basic elements may map into one or more (up to MB_LEN_MAX)
     bytes in a multibyte character.

     The current locale (setlocale(3)) governs the interpretation of wide and multibyte characters.  The locale category LC_CTYPE specifically
     controls this interpretation.  The wchar_t type is wide enough to hold the largest value in the wide character representations for all
     locales.

     Multibyte strings may contain 'shift' indicators to switch to and from particular modes within the given representation.  If explicit bytes
     are used to signal shifting, these are not recognized as separate characters but are lumped with a neighboring character.	There is always a
     distinguished 'initial' shift state.  Some functions (e.g., mblen(3), mbtowc(3) and wctomb(3)) maintain static shift state internally,
     whereas others store it in an mbstate_t object passed by the caller.  Shift states are undefined after a call to setlocale(3) with the
     LC_CTYPE or LC_ALL categories.

     For convenience in processing, the wide character with value 0 (the null wide character) is recognized as the wide character string termina-
     tor, and the character with value 0 (the null byte) is recognized as the multibyte character string terminator.  Null bytes are not permitted
     within multibyte characters.

     The C library provides the following functions for dealing with multibyte characters:

     Function	    Description
     mblen(3)	    get number of bytes in a character
     mbrlen(3)	    get number of bytes in a character (restartable)
     mbrtowc(3)     convert a character to a wide-character code (restartable)
     mbsrtowcs(3)   convert a character string to a wide-character string (restartable)
     mbstowcs(3)    convert a character string to a wide-character string
     mbtowc(3)	    convert a character to a wide-character code
     wcrtomb(3)     convert a wide-character code to a character (restartable)
     wcstombs(3)    convert a wide-character string to a character string
     wcsrtombs(3)   convert a wide-character string to a character string (restartable)
     wctomb(3)	    convert a wide-character code to a character

SEE ALSO

     mklocale(1), setlocale(3), stdio(3), big5(5), euc(5), gb18030(5), gb2312(5), gbk(5), mskanji(5), utf8(5)

STANDARDS

     These functions conform to ISO/IEC 9899:1999 (``ISO C99'').

BSD
								   April 8, 2004							       BSD