Re: Using Screen

["Andrew Brooks" <arb@sat.dundee.ac.uk>]

On Thu, 15 Jan 2009 18:38:01 -0000, Alain M. <alainm@pobox.com> wrote:
>
> Do you have instructions about using screen that you can share?

Below are my notes which I hope you find helpful.  The remote viewer
logs in with ssh and runs "start_viewer".  On the dos PC you have
already started "start_screen" which calls "start_dos".

> If it is still needed, I can digg info about installing DOS's fonts
> in the client machine. it should solve the box-drawing problem.

That would be useful, thanks.

Andrew


On the "viewer" PC

To view a dosemu session properly you need to open a terminal window
with the correct character encoding. eg. Gnome Terminal using IBM850.
Although the example below says UTF-8 for some reason.

DOSView.desktop:
[Desktop Entry]
Version=1.0
Encoding=UTF-8
Name=DOSView
Type=Application
Exec=ssh -t user@dospc /bin/bash -lc ./start_viewer
TryExec=
X-GNOME-DocPath=
Terminal=true
Name[en_US]=DOSView
GenericName[en_US]=
Comment[en_US]=
GenericName=
Comment=

Gnome terminal preferences are stored in ~/.gconf/apps/gnome-terminal

However Gnome terminal sucks up too much CPU time so xterm is better.
But I haven't yet found a way of getting the correct character encoding
in xterm.


On the "server" PC (let's call it dospc)

The start_viewer script:

---------------------------------------------------------
#!/bin/sh

numscreens=`ls ~user/tmp/*.drive | wc -l`
if [ 0$numscreens -ne 1 ]; then
        echo There is not a single screen session for attachment
        echo Is start_screen running?
        exit 1
fi

session=`basename ~opr/tmp/*.drive`
#screen -x $session
screen -rx
--------------------------------------------------------


The start_screen script:
--------------------------------------------------------
#!/bin/sh
# default terminal type is "linux" but use "vt100" because the
# line-drawing characters work better
export TERM=vt100
screen -S drive -s ./start_dos #-T ansi
--------------------------------------------------------


The start_dos script:
-------------------------------------------------------
#!/bin/sh
# 1.00 arb Thu Mar  3 12:12:44 GMT 2005
# Limit processes to 128MB of virtual memory (limit).
# Run dosemu in super-user mode in order to access hardware (-s).
# Automatically restart dosemu (after 30 seconds) if it fails.
vm_limit=131072     # KB
TZ=UTC0; export TZ  # Timezone without daylight savings
ulimit -v $vm_limit
while true; do
        dosemu -s
        echo Restarting dosemu in 30 seconds
        echo Press CTRL-C to abort
        sleep 30
done
-------------------------------------------------------


The .screenrc config file has the following additions:

multiuser on # allow multiple users
defc1 off    # allow 8-bit chars ("on" uses top bit set chars as control funcs)
vbell off    # use audible bell


The dosemu.conf config file changes:
$_term_char_set = "ibm"


When viewing using screen you can use ctrl-a then d to detach the
session and reconnect to it later.


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