luit - Locale and ISO 2022 support for Unicode terminals
] [ --
] [ program
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
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
is usually invoked transparently by the terminal emulator. For
information about running luit
from the command line, see EXAMPLES
- Display some summary help and quit.
- List the supported charsets and encodings, then quit.
- Print luit's version and quit.
- Be verbose.
- Function as a simple converter from standard input to
- In startup, establish a handshake between parent and child
processes. This is needed for some systems, e.g., FreeBSD.
- 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).
- -encoding encoding
- Set up luit to use encoding rather than the
current locale's encoding.
- Disable interpretation of single shifts in application
- Disable interpretation of locking shifts in application
- Disable interpretation of character set selection sequences
in application output.
- Disable interpretation of all sequences and pass all
sequences in application output to the terminal unchanged. This may lead
to interesting results.
- Generate seven-bit characters for keyboard input.
- Disable generation of single-shifts for keyboard
- 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.
- 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
- -olog filename
- Log into filename all the bytes sent to the terminal
- -alias filename
- the locale alias file
- End of options.
The most typical use of luit
is to adapt an instance of XTerm
the locale's encoding. Current versions of XTerm
automatically when it is needed. If you are using an older release of
, or a different terminal emulator, you may invoke luit
- $ 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
- $ LC_ALL=fr_FR luit ssh legacy-machine
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, versions of
that do not speak UTF-8 well can use luit
- $ luit -encoding 'ISO 8859-1' emacs -nw
And then, in Emacs
- M-x set-terminal-coding-system RET iso-2022-8bit-ss2
- The file mapping locales to locale encodings.
On systems with SVR4 (“Unix-98”) ptys (Linux version 2.2 and later,
should be run as the invoking user.
On systems without SVR4 (“Unix-98”) ptys (notably BSD variants),
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
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.
will refuse to run if it is installed setuid and cannot safely drop
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 supported and will never
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
originally written by Juliusz Chroboczek <firstname.lastname@example.org> for the
XFree86 Project and includes additional contributions from Thomas E. Dickey
required for newer releases of xterm(1)