monitoring "screen"

[papaschtroumpf]

I use the "screen" command a lot because I'm not always at my linux machine, but I can use SSH to access it from anywhere, so I can for example start a bittorrent download, an FTP download and restart my UT2004 server remotely and monitor them from somewhere else.

 

So I often have multiple screen sessions going (I'm downloading 3 different liveCDs as I type this for example).

 

I often want to check on all sessions at some time, for example to see how much time is left on a download, or if my game server is busy.

 

 

I don't know of a way to skip form one session to another from within screen, so I have to retype "screen -d -r xxxxx.pts-y.Mandrake" where xxxxx is the session number and y the terminal number. Is this truly not possible? it would be so convenient if you could press Ctrl-A + a key and mvoe to the next session.

 

 

Also, I'd like to have a cron job send me a status of the screen sessions, such as making sure that the torrents I'm seeding are still conencted to their tracker, or whatever.

Ideally I'd liketo simple capture a "snapshot" of a screen session to a file by simply issuing a command line. Is this possible at all?

 

 

I did read the screen man page, but for whatever reason most of it just doesn't register with my brain, for exampel from the man page I thoguh Ctrl-A + n would do exactly what I describe in my first question.

[Steve Scrimpshire]

If you start just one screen session and just create a new window for each command, you could do Ctrl-a <n> to switch between windows and then you only have one screen session to detach/reattach and deal with.

 

To create a new window:

 

Ctrl-a Ctrl-c

 

There's a way to name your windows, too, but I would have to look at 'man screen' a little longer to be able to help you there. As far as logging...I dunno, but I'm sure it's possible. When I get the time, I'll play around with it.

[Hirogen2]

I did read the screen man page, but for whatever reason most of it just doesn't register with my brain, for exampel from the man page I thoguh Ctrl-A + n would do exactly what I describe in my first question.

Read what it says.

 

Ctrl+A,Ctrl+N = next window

Ctrl+A,Ctrl+P = previous window

Ctrl+A,0 = 1st window

Ctrl+A,1 = 2nd window

and so on. (Ctrl-A + n was meant to be a number)

[iphitus]

hokai

currently you are using multiple different sessions, one for each command. you want to use one session for all of them.

 

in future start a command line with screen -D -R

 

this will start your session. Then run your command to do whatever. to add another command prompt to the session, press ctrl-a and then 'c' this will pop up a new command line. do whatever you like there. to swap between them, do ctrl-a, and then spacebar.

 

When you want to reattatch the session so you can access it, manipulate it, whatever, do: screen -D -R again.

 

iphitus.

[papaschtroumpf]

Yes, that's the par t I missed when I read the man page, you can get several "windows" within a single session.

[Steve Scrimpshire]

If you use separate windows instead of separate instances of screen, you can monitor them like this:

 

screen

Ctrl-a H <<starts logging output from that window to screenlog.0>>

btdownloadheadless.py <<whatever>>

Ctrl-a c <<starts a new window and switches to that window>>

Ctrll-a H <<starts logging output from that window to screenlog.1>>

btdownloadheadless.py <<whatever>>

Ctrl-a d <<detaches window>>

 

You can now see the output of each screen window with

cat screenlog.<<window#>>

 

Note that only the output of the windows is sent to the screenlog. The log seems all screwy if you use btdownloadcurses, which is why I suggest btdownloadheadless.py

Edited February 27, 2005 by Steve Scrimpshire