INTRO (7) NetBSD Miscellaneous Information Manual INTRO (7 ...

NLS (7) NetBSD Miscellaneous Information Manual NLS (7)
The implementation also doesn’t support different character sets. The gettext(3) interface has not been
standardized yet, however itisbeing supported by an increasing number of systems. It also provides many
additional tools which make programming and catalog maintenance much easier.
Support for Multi-byte Encodings
Some character sets with multi-byte encodings may be difficult to decode, or may contain state (i.e., adjacent
characters are dependent). ISO C specifies a set of functions using ’wide characters’ which can handle
multi-byte encodings properly. The behaviour of these functions is affected by the LC_CTYPE category of
the current locale.
Awide character is specified in ISO C as being a fixed number of bits wide and is stateless. There are two
types for wide characters: wchar_t and wint_t. wchar_t is a type which can contain one wide character and
operates like ’char’ type does for one character. wint_t can contain one wide character or WEOF (wide
EOF).
There are functions that operate on wchar_t, and substitute for functions operating on ’char’. See
wmemchr(3) and towlower(3) for details. There are some additional functions that operate on wchar_t.
See wctype(3) and wctrans(3) for details.
Wide characters should be used for all I/O processing which may rely on locale-specific strings. The two
primary issues requiring special use of wide characters are:
• All I/O is performed using multibyte characters. Input data is converted into wide characters
immediately after reading and data for output is converted from wide characters to multi-byte
encoding immediately before writing. Conversion is controlled by the mbstowcs(3),
mbsrtowcs(3), wcstombs(3), wcsrtombs(3), mblen(3), mbrlen(3), and mbsinit(3).
• Wide characters are used directly for I/O, using getwchar(3), fgetwc(3), getwc(3),
ungetwc(3), fgetws(3), putwchar(3), fputwc(3), putwc(3), and fputws(3). They are
also used for formatted I/O functions for wide characters such as fwscanf(3), wscanf(3),
swscanf(3), fwprintf(3), wprintf(3), swprintf(3), vfwprintf(3), vwprintf(3),
and vswprintf(3), and wide character identifier of %lc, %C, %ls, %S for conventional formatted
I/O functions.
SEE ALSO
gencat(1), xfd(1), xterm(1), catgets(3), gettext(3), nl_langinfo(3), setlocale(3),
wsfontload(8)
BUGS
This man page is incomplete.
NetBSD 3.0 February 21, 2007 6