You run long processes over SSH, perhaps over the WAN, and when you get disconnected you lose a lot of work. Or perhaps you started a long job from work, but need to go home and be able to check on the job later; you could run your process using nohup, but then you won’t be able to reattach to it when your connection comes back or you get home.
Install and use GNU screen.
Using screen is very simple. Type
-a option includes
all of screen’s capabilities even at the expense of
some redraw (thus bandwidth) efficiency. Honestly, we use
-a but have never noticed a difference.
When you do this, it will look like nothing happened, but you are
now running inside a screen.
$SHLVL should return a number greater than one if this worked
(see also :
L$SHLVL in Customizing Your Prompt). To test it, do an
ls -la, then
kill your terminal (do not exit cleanly, as
you will exit screen as well). Log back into the
machine and type
screen -r to
reconnect to screen. If that doesn’t put you back
where you left off, try
screen -d -r.
If that doesn’t work, try
ps auwx | grep
[s]creen to see if screen is still
running, and then try
man screen for
troubleshooting information—but it should just work. If you run into
problems with that ps command on a system other
than Linux, see Finding Out Whether a Process Is Running.
Starting screen with something like the following will make it easier to figure out what session to reattach ...