UTF-8(7)               Miscellaneous Information Manual               UTF-8(7)

<?><?><?>
       UTF-8 - ASCII-<?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?>

<?><?><?><?><?><?><?><?>
       The Unicode 3.0 character set occupies a 16-bit code space.  The most
       obvious Unicode encoding (known as UCS-2)  consists of a sequence of
       16-bit words.  Such strings can contain--as part of many 16-bit
       characters--bytes such as '\0' or '/', which have a special meaning in
       filenames and other C library function arguments.  In addition, the
       majority of UNIX tools expect ASCII files and can't read 16-bit words
       as characters without major modifications.  For these reasons, UCS-2 is
       not a suitable external encoding of Unicode in filenames, text files,
       environment variables, and so on.  The ISO/IEC 10646 Universal
       Character Set (UCS), a superset of Unicode, occupies an even larger
       code space--31 bits--and the obvious UCS-4 encoding for it (a sequence
       of 32-bit words) has the same problems.

       <?><?><?><?><?><?><?><?><?> UTF-8 <?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?> UCS
       <?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?><?> <?> UNIX-<?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?>.

   <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> UTF-8 <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?>:

       * UCS-<?><?><?><?><?><?><?> <?> <?><?><?><?><?><?> <?><?> 0x00000000
         <?><?> 0x0000007f (<?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
         US-ASCII) <?><?><?><?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?>
         <?> <?><?><?><?><?><?> <?><?> 0x00 <?><?> 0x7f (<?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?> ASCII). <?><?><?> <?><?><?><?><?><?><?><?>,
         <?><?><?> <?><?><?><?><?> <?> <?><?><?><?><?><?>,
         <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
         7-<?><?><?><?><?><?> ASCII-<?><?><?><?><?><?><?>, <?><?><?><?><?>
         <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?> <?> ASCII <?><?><?>
         <?> <?> UTF-8.

       * All UCS characters greater than 0x7f are encoded as a multibyte
         sequence consisting only of bytes in the range 0x80 to 0xfd, so no
         ASCII byte can appear as part of another character and there are no
         problems with, for example, '\0' or '/'.

       * <?><?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
         <?><?><?> <?> <?><?><?><?><?><?><?><?><?> UCS-4.

       * All possible 2^31 UCS codes can be encoded using UTF-8.

       * <?> <?><?><?><?><?><?><?><?><?> UTF-8 <?><?><?><?><?><?><?> <?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?> <?>
         <?><?><?><?><?><?> 0xc0, 0xc1, 0xfe <?> 0xff.

       * <?><?><?><?><?><?> <?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>,
         <?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?> <?><?> ASCII
         UCS-<?><?><?><?><?><?>, <?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?> <?><?>
         0xc2 <?><?> 0xfd <?> <?><?><?><?><?><?><?><?><?> <?><?>
         <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>. <?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?> <?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?> <?><?>
         0x80 <?><?> 0xbf. <?><?><?> <?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>,
         <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?> (statelessness) <?> <?><?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?> <?><?>
         <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>.

       * <?><?><?><?><?><?><?> UCS, <?><?><?><?><?><?><?><?><?><?><?><?><?><?>
         <?> UTF-8, <?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?>
         <?><?><?><?><?> <?><?><?><?><?><?>, <?><?><?><?><?><?> <?>
         <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?>
         <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?>
         0x10ffff, <?><?><?><?><?><?><?> <?> UTF-8 <?><?><?><?><?><?><?><?><?>
         <?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?>
         <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> 4
         <?><?><?><?><?>.

   <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>.
       <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?> <?><?><?><?><?><?> <?><?><?><?><?><?><?>
       <?> <?><?><?><?><?><?><?><?><?> UCS:

       0x00000000 - 0x0000007F:
           0xxxxxxx

       0x00000080 - 0x000007FF:
           110xxxxx 10xxxxxx

       0x00000800 - 0x0000FFFF:
           1110xxxx 10xxxxxx 10xxxxxx

       0x00010000 - 0x001FFFFF:
           11110xxx 10xxxxxx 10xxxxxx 10xxxxxx

       0x00200000 - 0x03FFFFFF:
           111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx

       0x04000000 - 0x7FFFFFFF:
           1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx

       <?><?><?><?><?><?><?> <?><?><?><?><?>,
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?> xxx,
       <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?> <?><?><?><?> <?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?>
       <?><?><?><?>, <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?> <?><?><?><?><?><?> (<?><?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?>).<?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>,
       <?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?> <?><?><?><?><?><?><?>.

       The UCS code values 0xd800-0xdfff (UTF-16 surrogates) as well as 0xfffe
       and 0xffff (UCS noncharacters) should not appear in conforming UTF-8
       streams.  According to RFC 3629 no point above U+10FFFF should be used,
       which limits characters to four bytes.

   <?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?> <?> <?><?><?><?><?> 0xa9 =
       1010 1001 (<?><?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>)
       <?><?><?><?><?><?><?><?><?><?> <?> UTF-8 <?><?><?>

              11000010 10101001 = 0xc2 0xa9

       <?> <?><?><?><?><?><?> <?> <?><?><?><?><?> 0x2260 = 0010 0010 0110 0000
       (<?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>)
       <?><?><?><?><?><?><?><?><?><?> <?><?><?>:

              11100010 10001001 10100000 = 0xe2 0x89 0xa0

   <?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?>, <?> <?><?><?><?><?><?><?>

              export LANG=en_GB.UTF-8

       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?> UTF-8 <?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> UTF-8 <?>
       <?><?><?><?><?><?><?><?><?><?><?>.

       <?><?><?><?><?><?><?><?><?>, <?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>,
       <?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?>
       <?><?><?><?><?><?><?>

              setlocale(LC_CTYPE, "")

       <?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?>

              strcmp(nl_langinfo(CODESET), "UTF-8") == 0

       to determine whether a UTF-8 locale has been selected and whether
       therefore all plaintext standard input and output, terminal
       communication, plaintext file content, filenames, and environment
       variables are encoded in UTF-8.

       Programmers accustomed to single-byte encodings such as US-ASCII or
       ISO/IEC 8859 have to be aware that two assumptions made so far are no
       longer valid in UTF-8 locales.  Firstly, a single byte does not
       necessarily correspond any more to a single character.  Secondly, since
       modern terminal emulators in UTF-8 mode also support Chinese, Japanese,
       and Korean double-width characters as well as nonspacing combining
       characters, outputting a single character does not necessarily advance
       the cursor by one position as it did in ASCII.  Library functions such
       as mbsrtowcs(3)  and wcswidth(3)  should be used today to count
       characters and cursor positions.

       The official ESC sequence to switch from an ISO/IEC 2022 encoding
       scheme (as used for instance by VT100 terminals) to UTF-8 is ESC % G
       ("\x1b%G").  The corresponding return sequence from UTF-8 to
       ISO/IEC 2022 is ESC % @ ("\x1b%@").  Other ISO/IEC 2022 sequences (such
       as for switching the G0 and G1 sets) are not applicable in UTF-8 mode.

   <?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?> UCS
       <?><?><?><?><?><?><?>, <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       UTF-8 <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>,
       <?><?> <?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?> <?><?><?><?><?><?>, <?><?><?><?><?><?> 0xc0,
       <?><?><?><?><?><?><?><?><?>. <?> <?><?><?><?><?><?><?><?><?> Unicode
       3.1 <?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?> <?><?><?><?><?>.
       <?><?><?> <?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?>:
       <?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?>, <?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       ASCII <?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <</../>>, <<;>>
       <?><?><?> NUL, <?><?><?> <?><?><?> <?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?> <?><?> ASCII <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?> <?><?>
       <?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?> UTF-8.

   <?><?><?><?><?><?><?><?><?>
       ISO/IEC 10646-1:2000, Unicode 3.1, RFC 3629, Plan 9.

<?><?>. <?><?><?><?><?>
       locale(1), nl_langinfo(3), setlocale(3), charsets(7), unicode(7)

<?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?> Azamat Hackimov <azamat.hackimov@gmail.com>, Dmitriy
       Ovchinnikov <dmitriyxt5@gmail.com>, Dmitry Bolkhovskikh
       <d20052005@yandex.ru>, Katrin Kutepova <blackkatelv@gmail.com>, Yuri
       Kozlov <yuray@komyakino.ru> <?> <?><?><?><?> <?><?><?><?><?><?>
       <pavia00@gmail.com>

       <?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?>;
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> GNU
       <?><?><?><?><?><?> 3 <https://www.gnu.org/licenses/gpl-3.0.html>
       <?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?>, <?><?><?><?><?>
       <?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>. <?><?> <?><?>
       <?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>.

       <?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?> <?><?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?>,
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?> <man-pages-ru-talks@lists.sourceforge.net>.

Linux man-pages 6.06    28 <?><?><?><?><?><?> 2024 <?>.               UTF-8(7)