Using Screen

Using Screen

[Julieto Agbay]

I search the mailing archive and could not found an entry related to
screen. I am not sure if what I found is a bug, feature request or
unsupported function at all.

Screen is a full-screen window manager that multiplexes a physical
terminal with interactive  shells.  See "man screen" for details or
"yum install screen" on CentOS systems is not installed yet.  What I
am am trying to do is to run DOSEMU in one of this virtual screen so
remote users of  a DOS program can share their session for debugging
and support.

I am using putty to ssh remote session with character set translation
of UTF-8.  Everything seems to display characters correctly but when
try to navigate the menu using arrow up/down, the session freezes or
hangs.  This DOS program is already running in a regular shell so I
hope this is only a configutation so DOS users can use virtual screen
to share their sessions.

rgds,

Re: Using Screen

[C.J. Adams-Collier]

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FWIW, I've seen this same issue.  I'd like to run a BBS on a server
and connect it to a PTY with ssh or something.  sysop console on a
screen.

But I'm a little light on the details.

I'll be listening intently :)

On Thu, Jan 15, 2009 at 07:44:45AM +0800, Julieto Agbay wrote:
> I search the mailing archive and could not found an entry related to
> screen. I am not sure if what I found is a bug, feature request or
> unsupported function at all.
> 
> Screen is a full-screen window manager that multiplexes a physical
> terminal with interactive  shells.  See "man screen" for details or
> "yum install screen" on CentOS systems is not installed yet.  What I
> am am trying to do is to run DOSEMU in one of this virtual screen so
> remote users of  a DOS program can share their session for debugging
> and support.
> 
> I am using putty to ssh remote session with character set translation
> of UTF-8.  Everything seems to display characters correctly but when
> try to navigate the menu using arrow up/down, the session freezes or
> hangs.  This DOS program is already running in a regular shell so I
> hope this is only a configutation so DOS users can use virtual screen
> to share their sessions.
> 
> rgds,
> --
> To unsubscribe from this list: send the line "unsubscribe linux-msdos" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

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Re: Using Screen

[Alain M.]

Hi,

I have been able to use ssh to open a dosemu session remotely, it 
requires installing some fonts only. Would this help?

BUT I am also very interested in screen, because it should allow a 
session to remain open and reconnect to it.

Alain

C.J. Adams-Collier escreveu:
> FWIW, I've seen this same issue.  I'd like to run a BBS on a server
> and connect it to a PTY with ssh or something.  sysop console on a
> screen.
> 
> But I'm a little light on the details.
> 
> I'll be listening intently :)
> 
> On Thu, Jan 15, 2009 at 07:44:45AM +0800, Julieto Agbay wrote:
>> I search the mailing archive and could not found an entry related to
>> screen. I am not sure if what I found is a bug, feature request or
>> unsupported function at all.
>>
>> Screen is a full-screen window manager that multiplexes a physical
>> terminal with interactive  shells.  See "man screen" for details or
>> "yum install screen" on CentOS systems is not installed yet.  What I
>> am am trying to do is to run DOSEMU in one of this virtual screen so
>> remote users of  a DOS program can share their session for debugging
>> and support.
>>
>> I am using putty to ssh remote session with character set translation
>> of UTF-8.  Everything seems to display characters correctly but when
>> try to navigate the menu using arrow up/down, the session freezes or
>> hangs.  This DOS program is already running in a regular shell so I
>> hope this is only a configutation so DOS users can use virtual screen
>> to share their sessions.
>>
>> rgds,

Re: Using Screen

[Andrew Brooks]

On Thu, 15 Jan 2009 16:37:15 -0000, Alain M. <alainm@pobox.com> wrote:
> I have been able to use ssh to open a dosemu session remotely, it
> requires installing some fonts only. Would this help?
>
> BUT I am also very interested in screen, because it should allow a
> session to remain open and reconnect to it.

I can confirm that I've used dosemu successfully in one screen session
and simultaneously accessed that session using a second connection
coming in remotely via ssh.  I had some trouble with DOS box-drawing
characters (unresolved) but no trouble that I recall with cursor keys.
Sorry I can't help but I can say that screen was useful with dosemu.

Andrew

Re: Using Screen

[Andrew Brooks]

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.


-------------------------------------------------------

Re: Using Screen

[Julieto Agbay]

Thanks Andrew for your notes.  I get hint from your script about the
terminal environment.  I guess this is needed.  I run this command and
the keyboard arrow up/down key is now captured correctly when running
DOSEMU.

[me@host ~]$ screen -U -T vt100

My test is continuing.

rgds,
Yul

On Fri, Jan 16, 2009 at 3:08 AM, Andrew Brooks <arb@sat.dundee.ac.uk> wrote:
> 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.
>
>
> -------------------------------------------------------
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-msdos" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>