Re: [screen-devel] feature request: screen session recovery after reboot

[Eric Wald]

On 10/20/07, Vaida Bogdan wrote:
> I've been a happy screen user for over 4 years and I use it daily on
> my desktop computer or while developing on a remote server. I found I
> needed only one feature more:
>
> --- the ability to resume sessions after a reboot ---
>
> What I mean by this is a way for screen to retain the last place it
> visited in each window, which file it edited and the commands history.

If you offer a decent programmer an extremely generous amount of money,
half of it up front, he can deliver a feature that almost approximates
what you desire, but reduces performance of the system as a whole, opens
files that no longer exist, and occasionally destroys things.  Anything
better is impossible by hacking screen alone.

What you really want is an interface that asks a program to save its
state, and start up in that state.  Every program on your system will
need to be modified to support that interface.  That will most likely
take more manpower than you can hire, unless you own Red Hat or Google.

Alternatively, you can hack the kernel to allow a program to save the
memory and resources of its child processes to disk.  Fortunately, most
of that work has been done, in the form of hibernation technology.
Unfortunately, the idea has serious security implications, and can fail
if the file system has changed at all; for example, if any time has
passed between the save point and a crash.  In fact, it probably will
fail unless the entire operating system is hibernated, which means that
manual reboots will be worthless.

I would advise against pursuing this dream.

- Eric