Bash – How to Call a .bashrc Function from a Bash Shell Script

bashfunctiongnome-terminalshell

I want to be able to name a terminal tab so I can keep track of which one is which. I found this function (here) and put it in my .bashrc:

function set-title() {
  if [[ -z "$ORIG" ]]; then
    ORIG=$PS1
  fi
  TITLE="\[\e]2;$*\a\]"
  PS1=${ORIG}${TITLE}
}

and now when I call set-title my new tab name the tab name is changed as expected to "my new tab name". The problem is that I want to open a new tab and name it using set-title. The way I have tried to do this, is like this:

gnome-terminal --geometry=261x25-0+0 --tab -e "bash -c 'set-title tab1; sleep 10'" --tab -e "bash -c 'set-title tab2; sleep 10"

However, now I get the following error message:

bash: set-title: command not found

And I think this is to do with the new gnome tab not knowing about the .bashrc function yet.

How can I get this to work?

Best Answer

Instant of using function set-title you can create command with this functionality, so remove function set-title() that you add from ~/.bashrc and create a file /usr/local/bin/set-title:

#!/bin/bash
echo -ne "\033]0;$1\007"

Add chmod: chmod +x /usr/local/bin/set-title. And after you re-open terminal you can use this command by: set-title TEST (If you have /usr/local/bin/ in your $PATH).

And then you can use it when creating new tab by this way:

gnome-terminal --geometry=261x25-0+0 \
    --tab -e "bash -c 'set-title TAB1; sleep 10'" \
    --tab -e "bash -c 'set-title TAB2; sleep 10'"

If you somehow don't have /usr/local/bin/ in your $PATH, you can try with absolute path to the set-title command:

--tab -e "bash -c '/usr/local/bin/set-title TAB1; sleep 10'"

-------- updated at 2011-11-15 22:00:00 --------

So... that worked for me on Solaris 11 Express, with gnome-terminal 2.30.2.

Since then, I've been able to test it on Ubuntu 11.04 (Natty), which uses 2.32.1, and found exactly the same behavior as you.

In the case of Ubuntu, I was able to track it to the ubuntu .bashrc file. In particular, the section that looks like:

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
    PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
    ;;
*)
    ;;
esac

In this case, the PS1 variable is being expanded for terminal types matching xterm* and rxvt*.

PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"

specifically the part between PS1="\[\e]0; and \a\]. Those get turned into the window title.

Once I commented out that whole case statement, the behavior of gnome-terminal with the -t option worked as expected. I'll see if I can find a CentOS 6 box to test this with, too.

-------- updated at 2017-11-1 09:38:00 --------

So it looks like more recent versions of Gnome-Terminal have made away with some useful features, like the simple -t option to set terminal titles.

It is still possible to set terminal titles at runtime, it's just ugly as hell now. You can use printf or echo in the command to effect a title.

For example:

To start a terminal window with 1 tab, titled 'My Fancy Title' using printf:

gnome-terminal --tab -e 'bash -c "printf \"\e]2;My Fancy Title\a\"; bash -i"'

To start a terminal window with 2 tabs, one running top, and one with a title, using echo:

gnome-terminal \
--tab -e 'bash -c "echo -ne \"\033]0;my tab running top\007\"; top"' \
--tab -e 'bash -c "echo -ne \"\033]0;My Fancy Title\007\"; bash -i"'

This does at least offer an option for setting the terminal title at runtime.

See this post for an option to put a simple function in your ~/.bashrc to allow for setting and resetting the title at will.

Shell – Change the current terminal tab title inside a shell script

The script works by setting the shell's interactive prompt to a string which includes control codes to manipulate the xterm window title. Each time the shell's prompt is displayed, the control codes to change the window title are output.

But of course, inside a script, no interactive prompt is ever displayed, so these commands have no observable effect (though if you started another interactive shell from within the script, you could see the window title change). And because no script can change the environment of its parent process, the change is lost once your script terminates.

Anyway, from your script, you could of course print out the control codes directly.

printf '\033]2;Hello\a'

This changes the window's title once, but if any other program later changes it again, your old title will be lost. The trick to change your prompt is widespread because some popular programs in the past would often change your window title soon after you changed it to your liking (though I don't think this is a common problem any longer). The drawback is that if something has a genuine reason to change your window title, that will now be superseded as soon as your shell displays its prompt again.

If you want code to change your current shell's prompt, you can't put those in a regular script; but you can source the script file, or put the commands in a shell function instead (commonly done in your Bash profile in order to make it persistent).

Incidentally, the Bash prompt should include additional control codes to tell Bash when a part of the prompt is effectively zero width, as far as calculating the display width of the prompt is concerned. You will find that line wrapping is erratic if you type a long command and then need to backspace, for example; Bash will attempt to redraw the prompt, but does it in the wrong place, because it thinks the screen control codes contribute to the prompt's width. You'll want to add these \[ and \] Bash control codes around them.

PS1="$ORIG\[$TITLE\]"

(The curly braces aren't really contributing anything, and hamper legibility, so I took them out.)

Best Answer

Related Solutions

How to launch gnome-terminal with unique titles for multiple tabs

-------- updated at 2011-11-15 22:00:00 --------

-------- updated at 2017-11-1 09:38:00 --------

Shell – Change the current terminal tab title inside a shell script

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