Re: customize Debian 11 evironment in lightdm (and in general?)

[David <bouncingcats@gmail.com>]

On Fri, 6 May 2022 at 04:24, Greg Wooledge <greg@wooledge.org> wrote:
> On Thu, May 05, 2022 at 06:48:49PM +0200, Giovanni Biscuolo wrote:

> > I'm trying to customize my user environment when using the lightdm
> > display manager (then the LXDE desktop environment)

Hello

TLDR: try defining the variables you need in ~/.xsessionrc

I don't have time to read the detail of the OP message, but
I use LXDE on Debian 11, so I can offer some information
that might be useful to others in the thread.

I configured all this years ago and it has been working ever since,
so I have forgotten all the details.

To achieve the same LXDE login configuration and environment
as a console login, I have these two lines in $HOME/.xsessionrc:
  . "/etc/profile"
  . "${HOME}/.profile"

(the double quotes just highlight strings in my editor)

The file $HOME/.xsessionrc is sourced by
  /etc/X11/Xsession
via
  /etc/X11/Xsession.d/40x11-common_xsessionrc
which contains this self-documentation:
  # This file is sourced by Xsession(5), not executed.
  # Source user defined xsessionrc (locales and other environment variables)

Some do-it-yourself tracing that I have placed into my scripts
when I was trying to figure out how to get this working informs me that
this is the sequence of events:
  lightdm(1310) > lightdm(1393) > Xsession(1414) . ~/.xsessionrc
  lightdm(1310) > lightdm(1393) > Xsession(1414)   . ~/.profile
  lightdm(1310) > lightdm(1393) > Xsession(1414)     . ~/bin/_my_export
  lightdm(1310) > lightdm(1393) > lxsession(1414) > lxpanel(1503) >
x-terminal-emul(2403) > bash(2433) . ~/.bashrc
The format of this data is:
  "parent(PID) > subparent(PID) > process(PID)
some_statement_invoked_in_a_sourced_script_indented_if_child_of_above_script"
The indented statements at the far right show the statements being
executed in my instrumented scripts.

So it appears that . ~/.profile runs when Xsession starts,
but ~/.bashrc is not run until I manually open a terminal
in LXDE, which appears in the above as x-terminal-emul.

I assume that Xsession and lxsession are the same process
because they have the same PID.

I have chosen to use lxterminal to provide x-terminal-emul.
One quirk of lxterminal is that there is only one process
which handles all open terminal windows.

~/bin/_my_export file is where I set and export environment variables
so that this file can be sourced by either ~/.profile or ~/.bashrc
as needed.