User Commands LUIT(1)
NAME
luit - Locale and ISO 2022 support for Unicode terminals
SYNOPSIS
/usr/bin/luit [ options ] [ -- ] [ program [ args ] ]
DESCRIPTION
Luit is a filter that can be run between an arbitrary appli-
cation 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 encoding 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 emula-
tor. For information about running luit from the command
line, see EXAMPLES below.
OPTIONS
-h Display some summary help and quit.
-list
List the supported charsets and encodings, then quit.
-v Be verbose.
-c Function as a simple converter from standard input to
standard output.
-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 encoding.
+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.
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User Commands LUIT(1)
+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 generating 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 g1.
-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.
-- End of options.
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User Commands LUIT(1)
EXAMPLES
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 multil-
ingual output. In particular, versions of Emacs that do not
speak UTF-8 well can use luit for multilingual output:
$ luit -encoding 'ISO 8859-1' emacs -nw
And then, in Emacs,
M-x set-terminal-coding-system RET iso-2022-8bit-ss2
RET
FILES
/usr/lib/X11/fonts/encodings/encodings.dir
The system-wide encodings directory.
/usr/share/X11/locale/locale.alias
The file mapping locales to locale encodings.
SECURITY
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), running 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.
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User Commands LUIT(1)
BUGS
None of this complexity should be necessary. Stateless
UTF-8 throughout 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 sup-
ported and will never be.
SEE ALSO
xterm(1), Character Code Structure and Extension Techniques
(ISO 2022, ECMA-35), Control Functions for Coded Character
Sets (ISO 6429, ECMA-48).
AUTHOR
The version of Luit included in this X.Org Foundation
release was originally written by Juliusz Chroboczek
for the XFree86 Project.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | terminal/luit |
|_____________________________|_____________________________|
| Interface Stability | Uncommitted |
|_____________________________|_____________________________|
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