$Revision: 1.6 $, Last modified: Wed Jan 7 14:34:31 EST 1998
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.
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"
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;stringBEL Set icon name and window title to string ESC]1;stringBEL Set icon name to string ESC]2;stringBEL Set window title to stringwhere 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.
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 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 $TERM in
xterm*)
precmd () {print -Pn "\e]0;%n@%m: %~\a"}
;;
esac
This could also be achieved by using chpwd() instead
of precmd().
bash supplies a variable PROMPT_COMMAND which contains a command to execute before the prompt. This example (inserted in ~/.bashrc) sets the title to "username@hostname: directory":
PROMPT_COMMAND='echo -ne "\033]0;${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 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 ($TERM)
case "xterm*":
set prompt="%{\033]0;%n@%m:%~\007%}tcsh%% "
breaksw
default:
set prompt="tcsh%% "
breaksw
endsw
which sets a prompt of "tcsh% ", and an xterm title and icon
of "username@hostname: directory". Note that
the "%{...%}" must be placed around escape sequences (and cannot
be the last item in the prompt: see 'man tcsh' for the details).
This is very difficult indeed in csh, and we end up doing something like the following (in ~/.cshrc):
switch ($TERM)
case "xterm*":
set host=`hostname`
set user=`whoami`
alias cd 'cd \!*; set prompt="^[]0;${user}@${host}: ${cwd}^Gcsh% "'
breaksw
default:
set prompt='csh% '
breaksw
endsw
where we have had to alias the cd command to do all the work of
setting the prompt. Note that the '^[' and '^G' in
the prompt string are single characters for ESC and BEL
(can be entered in emacs using 'C-q ESC' and 'C-q C-g').
I strongly recommend abandoning csh in favour of a more advanced shell: zsh, bash or tcsh.
ksh provides little in the way of functions and expansions, so we have to insert the escape string in the prompt to have it updated dynamically. This example produces a title of "username@hostname: directory" and a prompt of "ksh$ ".
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').
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 stringFor the full list of xwsh escapes see xwsh(1G).
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 stringThese are truly awful programs: use something else.
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?).
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