ADC Home > Reference Library > Reference > Mac OS X > Mac OS X Man Pages
|
This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles. For more information about the manual page format, see the manual page for manpages(5). |
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 sup-ports supports ports two different ways of dealing with extended natural language encod-ings: encodings: ings: wide characters and multibyte characters. Wide characters are an internal representation which allows each basic element to map to a sin-gle single gle 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 distin-guished distinguished guished `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 cate-gories. categories. gories. For convenience in processing, the wide character with value 0 (the null wide character) is recognized as the wide character string terminator, 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 |