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Updated: Wednesday, February 9, 2022

luit (1)


luit - Locale and ISO 2022 support for Unicode terminals


luit [ options ] [ -- ] [ program [ args ] ]


LUIT(1)                     General Commands Manual                    LUIT(1)

       luit - Locale and ISO 2022 support for Unicode terminals

       luit [ options ] [ -- ] [ program [ args ] ]

       Luit is a filter that can be run between an arbitrary application and a
       UTF-8 terminal emulator.  It will convert application output  from  the
       locale's  encoding  into  UTF-8,  and convert terminal input from UTF-8
       into the locale's encoding.

       An application may also request switching to a different output  encod-
       ing  using ISO 2022 and ISO 6429 escape sequences.  Use of this feature
       is  discouraged:  multilingual  applications  should  be  modified   to
       directly generate UTF-8 instead.

       Luit  is  usually  invoked transparently by the terminal emulator.  For
       information about running luit from  the  command  line,  see  EXAMPLES

       -h     Display some summary help and quit.

       -list  List the supported charsets and encodings, then quit.

       -V     Print luit's version and quit.

       -v     Be verbose.

       -c     Function  as  a simple converter from standard input to standard

       -p     In startup, establish a handshake between parent and child  pro-
              cesses.  This is needed for some systems, e.g., FreeBSD.

       -x     Exit  as  soon  as  the child dies.  This may cause luit to lose
              data at the end of the child's output.

       -argv0 name
              Set the child's name (as passed in argv[0]).

       -encoding encoding
              Set up luit to use encoding rather  than  the  current  locale's

       +oss   Disable interpretation of single shifts in application output.

       +ols   Disable interpretation of locking shifts in application output.

       +osl   Disable  interpretation  of character set selection sequences in
              application output.

       +ot    Disable interpretation of all sequences and pass  all  sequences
              in  application output to the terminal unchanged.  This may lead
              to interesting results.

       -k7    Generate seven-bit characters for keyboard input.

       +kss   Disable generation of single-shifts for keyboard input.

       +kssgr Use GL codes after  a  single  shift  for  keyboard  input.   By
              default, GR codes are generated after a single shift when gener-
              ating eight-bit keyboard input.

       -kls   Generate locking shifts (SO/SI) for keyboard input.

       -gl gn Set the initial assignment of GL.  The argument should be one of
              g0,  g1,  g2  or  g3.  The default depends on the locale, but is
              usually g0.

       -gr gk Set the initial assignment of GR.  The default  depends  on  the
              locale,  and  is  usually g2 except for EUC locales, where it is

       -g0 charset
              Set the charset initially selected in G0.  The  default  depends
              on the locale, but is usually ASCII.

       -g1 charset
              Set  the  charset initially selected in G1.  The default depends
              on the locale.

       -g2 charset
              Set the charset initially selected in G2.  The  default  depends
              on the locale.

       -g3 charset
              Set  the  charset initially selected in G3.  The default depends
              on the locale.

       -ilog filename
              Log into filename all the bytes received from the child.

       -olog filename
              Log into filename all the bytes sent to the terminal emulator.

       -alias filename
              the locale alias file
              (default: /usr/share/X11/locale/locale.alias).

       --     End of options.

       The most typical use of luit is to adapt an instance of  XTerm  to  the
       locale's encoding.  Current versions of XTerm invoke luit automatically
       when it is needed.  If you are using an older release of  XTerm,  or  a
       different terminal emulator, you may invoke luit manually:

              $ xterm -u8 -e luit

       If  you  are  running  in  a  UTF-8  locale but need to access a remote
       machine that doesn't support UTF-8, luit can adapt the remote output to
       your terminal:

              $ LC_ALL=fr_FR luit ssh legacy-machine

       Luit  is  also useful with applications that hard-wire an encoding that
       is different from the one normally used on the system or  want  to  use
       legacy  escape  sequences for multilingual output.  In particular, ver-
       sions of Emacs that do not speak UTF-8 well can use luit for  multilin-
       gual output:

              $ luit -encoding 'ISO 8859-1' emacs -nw

       And then, in Emacs,

              M-x set-terminal-coding-system RET iso-2022-8bit-ss2 RET

              The file mapping locales to locale encodings.

       On  systems  with  SVR4  ("Unix-98") ptys (Linux version 2.2 and later,
       SVR4), luit should be run as the invoking user.

       On systems without SVR4 ("Unix-98") ptys (notably BSD  variants),  run-
       ning  luit  as an ordinary user will leave the tty world-writable; this
       is a security hole, and luit will generate a warning (but still  accept
       to  run).   A  possible solution is to make luit suid root; luit should
       drop privileges sufficiently early to make  this  safe.   However,  the
       startup code has not been exhaustively audited, and the author takes no
       responsibility for any resulting security issues.

       Luit will refuse to run if it is installed  setuid  and  cannot  safely
       drop privileges.

       None  of this complexity should be necessary.  Stateless UTF-8 through-
       out the system is the way to go.

       Charsets with a non-trivial intermediary byte are not yet supported.

       Selecting alternate sets of control characters  is  not  supported  and
       will never be.

       See attributes(7) for descriptions of the following attributes:

       |Availability   | terminal/luit    |
       |Stability      | Volatile         |

       xterm(1), locale(7),
       Character Code Structure and Extension Techniques (ISO 2022, ECMA-35).
       Control Functions for Coded Character Sets (ISO 6429, ECMA-48).

       The version of Luit included in this X.Org Foundation release was orig-
       inally written by  Juliusz  Chroboczek  <jch@freedesktop.org>  for  the
       XFree86  Project  and  includes additional contributions from Thomas E.
       Dickey required for newer releases of xterm(1).

       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source   was   downloaded   from    https://www.x.org/releases/individ-

       Further information about this software can be found on the open source
       community website at https://www.x.org.

X Version 11                      luit 1.1.1                           LUIT(1)