problems with system-config-display and crtl-alt-backspace

[Paul Allen Newell]

Suvayu and Ed:

Thanks for these replies. Points taken as they help me see the 
weaknesses in my understanding. So, yeah, I got hacking / homework ahead 
... and seeing if I can figure out enough to feel comfortable learning / 
switch to bash from tcsh.

Paul

Suvayu Ali wrote:
> Hi Paul,
>
> On Monday 28 December 2009 09:21 PM, Paul Allen Newell wrote:
>> Ed Greshko wrote:
>>>
>>> The man page tells you under what conditions the various files
>>> (/etc/profile, ~/.bash_profile ~/.bash_login etc) are read depending on
>>> what type of shell (interactive, login).
>>> Are you saying there is a situation not covered?
>>>
>>> Remember, everything that is executed is executed under a shell.
>>
>> I think part of my confusion is that I am not understanding whether a
>> login shell covers everything that is done once I have logged in via
>> splash screen or if it is confined to "logining into a shell". If the
>> former, then I would assume bash_profiles is hit once and everything
>> done thereafter would be under its command. If the latter, then I am
>> probably unclear about whether launching a terminal is a "login" act
>> (hence under bash_profile only within that shell).
>>
>
> I think a small experiment is in order. Open up any terminal emulator 
> of your choice, go fullscreen (well just stretching it to be really 
> big should be enough for the experiment ;) )
>
> Now run the following,
>
> $ ps uf -u `whoami`
>
> The output might be a little truncated on the right depending on the 
> size of your monitor, but that is not too important. As you can see, 
> the command to start your desktop is initiated by a shell. So if you 
> setup your environment variables appropriately, then all those should 
> be available to the shell starting your desktop. This allows you to 
> have a consistent environment for your applications no matter how you 
> launch them, from a terminal or from the gui of your desktop.
>
> The lesson to learn here are the differences between shells/apps 
> inheriting the environment of its parent shell/process depending on 
> how you set the environment.
>
> If you are interested, you can try another small experiment to see for 
> yourself what I mean. Try putting this in your ~/.bash_profile,
>
> export PATH=$PATH:${HOME}/bin
>
> And then put a symbolic link to some small application of your choice 
> in your ${HOME}/bin.
>
> For example I did this, (I chose thunar as I use XFCE)
>
> $ ln -s -T `which thunar` ${HOME}/bin/fakethunar
>
> Now logout and log back in. Try running `fakethunar' with the Alt-F2 
> dialogue. It will open up thunar. Now comment out those lines, logout, 
> login again and repeat that. You will get an error message. You can do 
> many different variations of this to explore some more subtleties. But 
> I think this paints a clearer picture now. :)
>
>>
>> Paul
>>
>
> Have fun hacking.
>
> PS: This kind of info is usually in the FILES or INVOCATION section of 
> the man pages.