Mc Digest, Vol 43, Issue 9

kilgota at banach.math.auburn.edu kilgota at banach.math.auburn.edu
Tue Dec 11 05:57:03 UTC 2007


A note in regard to:

>>>
>>>> previous posters wrote:
>>> |>>> Do you refer to the notorious "The shell is already running a
>>>> command" issue ?
>>>
>>> |>> Yes, this one exactly.
>>>
>>>> |Ok. Yes - it is really hard to fix. You've been around for many years
>>>> |now so I'd expect you to know more about this issue. Anyway...
>>>> .... snip ..
>>>> | It really is not
>>>> |that simple to fix it. And it really isn't and error.
>>>> ==================
>>>> It's not an error, but it's very annoying.
>>>> I.e. it doesn't have a technical solution, but it does
>>>> have a 'socio-managment' solution: just make it known up-front
>>>> and suggest a work around.
>>>
>>>> The problem which is as annoying as "getting a mesg to first
>>>> complete some other task, when you want to apply breaks on
>>>> your vehicle", and should not be trivialised.
>>>
>>>> Only after much frustration did I find a work-around:
>>>> * Ctrl O to get 'behind the current ?shell?',
>>>> * Ctrl C to stop/attend to the 'problematic proccess',
>>>> * ls : just to select some task to confirm that some thing
>>>>     can be done,
>>>> * Ctrl O to get back to select what was intended to be done.

I have been thinking about this exchange, and, based upon reflection, 
I will mention one thing which triggers this problem and IMHO it ought not 
to trigger any problem:


Run a command either (a) from the MC command shell, or (b) from a command 
prompt obtained by Cntrl-O (having put MC into the background).

If having done (a), then do Cntrl-O

and then do Shift-PageUp to look at any debug output from the command.

Or, if having done (b) then MC is already in the background (having 
previously been started and you did Cntrl-O before running the command 
instead of after)

So, in case (b) also do Shift-PageUp to look at debug output from the 
command.

It matters not which sequence one followed, and it also matters not if one 
has pressed Enter or the Down-arrow key to get back to the command prompt. 
In either case, if one now does Cntrl-O and pulls up MC in the foreground 
again, then when one tries to run the next command from the command line 
at the bottom of the MC display, there is the error message

"The shell is already running a command"

and progress is blocked until one does Cntrl-O, then Enter, then Cntrl-O 
again, and then the command is still sitting at the command prompt at the 
bottom of MC's blue screen, unexecuted, still waiting to be run.

This is irritating, in part because it is not natural to regard 
Shift-PageUp as something which is exactly a command, particularly if the 
user perceives that he/she has been conscientious and has already taken 
the trouble to make sure that the effect of the Shift-PageUp has been 
"cleared" by making sure that the cursor has been brought back to the 
command prompt.

Is it not possible for certain key combinations such as Shift-PageUp to be 
detected as what they are, as not being in the same category as shell 
commands which have or may have initiated some process, and then 
either ignored, cancelled, or overridden? Perhaps it is not possible. Not 
saying it is. Just asking.

Theodore Kilgore



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