home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Magazyn Enter 1999 June
/
enter_06_1999.iso
/
doc
/
HOWTO
/
mini
/
Xterm-Title
< prev
next >
Wrap
Text File
|
1998-10-14
|
11KB
|
362 lines
HOW TO CHANGE THE TITLE OF AN XTERM
Richard Lister, ric@giccs.georgetown.edu
$Revision: 1.6 $, Last modified: Wed Jan 7 14:34:31 EST 1998
_________________________________________________________________
_This document explains how to use escape sequences to dynamically
change window and icon titles of an xterm. Examples are given for
several shells, and the appendix gives escape sequences for some other
terminal types._
_________________________________________________________________
* Where to find this document
* Static titles
* Dynamic titles
* Examples for different shells
+ zsh
+ bash
+ tcsh
+ csh
+ ksh
* Appendix: escapes for other terminal types
+ SGI wsh, xwsh and winterm
+ CDE dtterm
+ Sun cmdtool and shelltool
+ Example
* Credits
_________________________________________________________________
Where to find this document
This document is now part of the Linux HOWTO Index and can be found at
http://sunsite.unc.edu/LDP/HOWTO/mini/Xterm-Title.html.
The latest version can always be found at
http://www.giccs.georgetown.edu/~ric/howto/Xterm-Title.html.
_________________________________________________________________
Static titles
A static title may be set for any of the terminals xterm, color-xterm
or rxvt, by using the -T and -n switches:
xterm -T "My XTerm's Title" -n "My XTerm's Icon Title"
Dynamic titles
Many people find it useful to set the title of a terminal to reflect
dynamic information, such as the name of the host the user is logged
into, the current working directory, etc.
This may be done by using XTerm escape sequences. The following
sequences are useful in this respect:
ESC]0;_string_BEL Set icon name and window title to _string_
ESC]1;_string_BEL Set icon name to _string_
ESC]2;_string_BEL Set window title to _string_
where ESC is the _escape_ character (\033), and BEL is the _bell_
character (\007).
_Note_: these sequences apply to most xterm derivatives, such as
nxterm, color-xterm and rxvt. Other terminal types often use different
escapes; see the appendix for examples. For the full list of xterm
escape sequences see the file ctlseq2.txt, which comes with the xterm
distribution, or xterm.seq, which comes with the rxvt distribution.
These escapes really need to be applied every time the prompt changes.
This way the string is updated with every command you issue and can
keep track of information such as current working directory, username,
hostname, etc. Some shells provide special functions for this purpose,
some don't and we have to insert the title sequences directly into the
prompt string.
_________________________________________________________________
Examples for different shells
In all the examples below we test the environment variable TERM to
make sure we only apply the escapes to xterms. We test for
TERM=xterm*; the wildcard is because some variants (such as rxvt) can
set TERM=xterm-color.
zsh
zsh provides some functions and expansions, which we will use:
precmd () a function which is executed just before each prompt
chpwd () a function which is executed whenever the directory is changed
\e escape sequence for escape (ESC)
\a escape sequence for bell (BEL)
%n expands to $USERNAME
%m expands to hostname up to first '.'
%~ expands to directory, replacing $HOME with '~'
There are many more expansions available: see 'man zshmisc'.
Thus, the following inserted in ~/.zshrc will set the xterm title to
"_username_@_hostname_: _directory_" ...
case $TERM in
xterm*)
precmd () {print -Pn "\e]0;%n@%m: %~\a"}
;;
esac
This could also be achieved by using chpwd() instead of precmd().
bash
bash supplies a variable PROMPT_COMMAND which contains a command to
execute before the prompt. This example (inserted in ~/.bashrc) sets
the title to "_username_@_hostname_: _directory_":
PROMPT_COMMAND='echo -ne "\033]0;${USER}@${HOSTNAME}: ${PWD}\007"'
where \033 is the character code for ESC, and \007 for BEL. Note that
the quoting is important here: variables are expanded in "...", and
not expanded in '...'. So PROMPT_COMMAND is set to an unexpanded
value, but the variables inside "..." are expanded when PROMPT_COMMAND
is used.
However, PWD produces the full directory path. If we want to use the
'~' shorthand we need to embed the escape string in the prompt, which
allows us to take advantage of the following prompt expansions
provided by the shell:
\u expands to $USERNAME
\h expands to hostname up to first '.'
\w expands to directory, replacing $HOME with '~'
\[...\] embeds a sequence of non-printing characters
Thus, the following produces a prompt of "bash$ ", and an xterm title
of "_username_@_hostname_: _directory_" ...
case $TERM in
xterm*)
PS1="\[\033]0;\u@\h: \w\007\]bash\$ "
;;
*)
PS1="bash\$ "
;;
esac
Note the use of \[...\], which tells bash to ignore the non-printing
control characters when calculating the width of the prompt. Otherwise
line editing commands get confused while placing the cursor.
tcsh
tcsh has functions and expansions similar to those of zsh:
precmd () a function which is executed just before each prompt
cwdcmd () a function which is executed whenever the directory is changed
%n expands to username
%m expands to hostname
%~ expands to directory, replacing $HOME with '~'
Unfortunately, there is no equivalent to zsh's print command allowing
us to use prompt escapes in the title string, so the best we can do is
to use shell variables (in ~/.tcshrc):
switch ($TERM)
case "xterm*":
alias precmd 'echo -n "\033]0;${HOST}:$cwd\007"'
breaksw
endsw
but this gives the directory's full path instead of using '~'. Instead
you can insert the string in the prompt:
switch ($TERM)
case "xterm*":
set prompt="%{\033]0;%n@%m:%~\007%}tcsh%% "
breaksw
default:
set prompt="tcsh%% "
breaksw
endsw
which sets a prompt of "tcsh% ", and an xterm title and icon of
"_username_@_hostname_: _directory_". Note that the "%{...%}" must be
placed around escape sequences (and cannot be the last item in the
prompt: see 'man tcsh' for the details).
csh
This is very difficult indeed in csh, and we end up doing something
like the following (in ~/.cshrc):
switch ($TERM)
case "xterm*":
set host=`hostname`
set user=`whoami`
alias cd 'cd \!*; set prompt="^[]0;${user}@${host}: ${cwd}^Gcsh% "'
breaksw
default:
set prompt='csh% '
breaksw
endsw
where we have had to alias the cd command to do all the work of
setting the prompt. Note that the '^[' and '^G' in the prompt string
are single characters for ESC and BEL (can be entered in emacs using
'C-q ESC' and 'C-q C-g').
I strongly recommend abandoning csh in favour of a more advanced
shell: zsh, bash or tcsh.
ksh
ksh provides little in the way of functions and expansions, so we have
to insert the escape string in the prompt to have it updated
dynamically. This example produces a title of "_username_@_hostname_:
_directory_" and a prompt of "ksh$ ".
case $TERM in
xterm*)
HOST=`hostname`
PS1='^[]0;${USER}@${HOST}: ${PWD}^Gksh$ '
;;
*)
PS1='ksh$ '
;;
esac
However, PWD produces the full directory path. We can remove the
prefix of $HOME/ from the directory using the ${...##...} construct.
We can also use ${...%%...} to truncate the hostname:
HOST=`hostname`
HOST=${HOST%%.*}
PS1='^[]0;${USER}@${HOST}: ${PWD##${HOME}/}^Gksh$ '
Note that the '^[' and '^G' in the prompt string are single characters
for ESC and BEL (can be entered in emacs using 'C-q ESC' and 'C-q
C-g').
_________________________________________________________________
Appendix: escapes for other terminal types
SGI wsh, xwsh and winterm
These terminals set TERM=iris-ansi and use the following escapes:
ESC P 1 .y _string_ ESC \\ Set window title to _string_
ESC P 3 .y _string_ ESC \\ Set icon title to _string_
For the full list of xwsh escapes see xwsh(1G).
Sun cmdtool and shelltool
cmdtool and shelltool both set TERM=sun-cmd and use the following
escapes:
ESC ] l _string_ ESC \ Set window title to _string_
ESC ] L _string_ ESC \ Set icon title to _string_
These are truly awful programs: use something else.
CDE dtterm
dtterm sets TERM=dtterm, and appears to recognise both the standard
xterm escape sequences and the Sun cmdtool sequences. (I've only
tested this on a Sun ... anyone have HP and DEC versions they can test
for me?).
Example
Here's my full setup using zsh to handle all these terminal types:
case $TERM in
xterm*|dtterm)
precmd () {print -Pn "\e]0;%n@%m: %~\a"} ## window & icon title
;;
iris-ansi)
precmd () {
print -Pn "\eP1.y%n@%m: %~\e\\" ## window title
print -Pn "\eP3.y%n@%m: %~\e\\" ## icon title
}
;;
sun-cmd)
precmd () {
print -Pn "\e]l%n@%m: %~\e\\" ## window title
print -Pn "\e]L%n@%m: %~\e\\" ## icon title
}
;;
esac
_________________________________________________________________
Credits
Thanks to the following people.
Paul D. Smith <psmith@BayNetworks.COM> and Christophe Martin
<cmartin@ipnl.in2p3.fr>
both pointed out that I had the quotes the wrong way round in
the bash PROMPT_COMMAND. Getting them right means variables
_are_ expanded dynamically.
Paul D. Smith <psmith@BayNetworks.COM>
suggested the use of \[...\] in the bash prompt for embedding
non-printing characters.
Christophe Martin <cmartin@ipnl.in2p3.fr>
provided the solution for ksh.
Keith Turner <keith@silvaco.com>
supplied the escape sequences for Sun cmdtool and shelltool.
_________________________________________________________________