do not reset PS1

[juhp]

Describe the bug Toolbox currently overrides the shell prompt (PS1). I feel it would be better if it just prepended ⬢ to the existing PS1 rather than overwriting the setting.

Steps how to reproduce the behaviour For example for Fedora 39 the default bash prompt (now green) is:

petersen@localhost-live:~$ 

which on toolbox enter then changes to:

⬢[petersen@toolbox ~]$ 

Expected behaviour I think it would be good if the prompt just modified to:

⬢petersen@toolbox:~$ 

Then the prompt would also be closer to (derived from) the default system prompt for the toolbox container OS I think.

Actual behaviour

⬢[petersen@toolbox ~]$ 

[debarshiray]

This is a good point!

I remember trying to prepend to PS1 when I first did this, and for some reason it didn't work. It might have been due to the order in which PS1 is set by the start-up scripts on Fedora for Bash as a login shell. I don't remember.

[juhp]

It is a little tricky since the setup order of PS1 is different for a fedora bash login shell, but I got it working now with bash-color-prompt after changing toolbox.sh to:

    [ "${BASH_VERSION:-}" != "" ] && PS1="\[\033[35m\]⬢\[\033[0m\] ${PS1@P}"

But without it, one gets ⬢bash-5.2$ which is perhaps what you ran into?

In a sense toolbox.sh is setting (modifying) PS1 too early (ie before /etc/bashrc has set the fedora default prompt, and hence it then no longer detects it is a bash default prompt...). Arguably that is also a Fedora bug in my mind - not sure the reason.

[debarshiray]

You seem to have jogged my memory a bit. I think it had something to do with the order in which the snippets in /etc/profile.d are invoked depending on whether Bash is invoked as a login shell or a non-login shell. The order isn't stable. My memory is still very vague. :)

Anyway, if you have already found a way to improve the situation, then feel free to file a pull request against Toolbx or Fedora's shell start-up scripts, whichever is appropriate. Or, I can dig into it later myself.

[swick]

Just to add one more data point: for developing mutter we use a script to create a nested D-Bus session and it modifies PS1 to show the prompt is in this nested session. This is broken currently on toolbox and I often am not sure if a terminal is in this nested D-Bus context or not.

[glemco]

This may have side effects, but what about not touching PS1 at all and just overriding the PROMPT_COMMAND, it may fight with vte.sh in case the command is not an array, this works on Fedora 40:

PROMPT_COMMAND+=('printf "\033[35m⬢\033[0m"')

[debarshiray]

This may have side effects, but what about not touching PS1 at all and just overriding the PROMPT_COMMAND, it may fight with vte.sh in case the command is not an array, this works on Fedora 40:

PROMPT_COMMAND+=('printf "\033[35m⬢\033[0m"')

That's actually a really interesting idea.

We need to check if PROMPT_COMMAND is an array on all the operating systems we claim to support. ie., Arch, Fedora, RHEL and Ubuntu. We could perhaps fall back to the current approach if PROMPT_COMMAND is not an array?

[debarshiray]

The current approach with the hexagon doesn't work on some host/container combinations. eg., Arch and Ubuntu, but I forgot the details. I wonder if one of these ideas improve that situation or something can be done to improve it.