Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!yale!cmcl2!kramden.acf.nyu.edu!brnstnd
From: brnstnd@kramden.acf.nyu.edu (Dan Bernstein)
Newsgroups: comp.unix.wizards
Subject: Re: Session management
Message-ID: <14760:Aug2714:50:2990@kramden.acf.nyu.edu>
Date: 27 Aug 90 14:50:29 GMT
References: <8319:Aug2617:20:3690@kramden.acf.nyu.edu> <105387@convex.convex.com> <MOSS.90Aug27081600@ibis.cs.umass.edu>
Organization: IR
Lines: 47

In article <MOSS.90Aug27081600@ibis.cs.umass.edu> moss@cs.umass.edu writes:
> An additional feature I definitely want is for the session manager to retain a
> session for some user-selectable time (with a system chosen upper bound) if
> the remote end drops before logout.

I agree, and pty does this too! It's very nice to be able to just flip
my terminal off in case of trouble, then reconnect later from anywhere.
I don't know how I lived without this feature.

pty doesn't implement the time limit: I was thinking of including it in
the code, but it's easy enough to do manually. (Under the session, check
every once in a while through sesslist. If the session is disconnected
and has the same signaller at two successive checks, kill -HUP all the
processes and sesskill the session.)

> I lose modem connections because of noise
> frequently, and it is really annoying to have to reconstruct my whole job tree
> when that happens.

Agreed. pty also lets you manually disconnect. This machine had to be
taken down a couple of days ago, but before that I had a single shell
running for a month. I just disconnected and reconnected every time,
saving on shell startup time, eliminating the need for vi -r, and
generally reducing angst.

> (The VMS pty stuff keeps sessions around as described, and
> when you relogin you get the option of connecting to your abandoned job or
> creating a new one.)

I source this script early in my login sequence (before aliases):

$HOME/links/sesslist
$HOME/links/sesslist | grep -s disconnected \
  && ( echo -n 'Reconnect to session (return to ignore): '; \
       set reconnect="$<"; \
       if ( a"$reconnect"b != ab ) exec sess reconnect "$reconnect"; \
     )

Primitive, but it gets the job done. A few minutes ago I just typed qf
and popped back into this session.

Once again, pty 3.001, the ultimate pseudo-terminal manager (implemented
for BSD variants only at the moment), will appear soon on c.s.unix. If
you're desperate, ask rsalz@bbn.com. If you're really desperate, anon
ftp to the pub/ directory on 128.122.128.22.

---Dan