Re: How to persist text on the screen when the client exits?

Hi Richard,

I've attached a VERY quick and dirty "proxy" script / hack that might help.
It keeps a persistent connection to a remote server (such as lcdproc), and
passes data from one active client client (at a given moment) to the remote
server.

Start it as a background process, or add code to your script to fork a
"proxy" process once when you are not able to connect to it. (Then again, a
duplicate process will just die harmlessly)

Just update the host & port settings to reflect your lcdproc settings. Only
1-way comms is implemented.

Regards,
Niel

On 2 January 2013 01:59, Richard Neill <[email protected]> wrote:

> Dear Eric,
>
> Thanks for your quick reply.
>
> I'm afraid that my simplified bash script
> may have added confusion - I do know about the -t option for the client.
> Also, I'd rather not respawn python every time - but in this case it's OK
> (the performance hit, while wasteful, is not actually an issue). The
> machine I'm monitoring is actually an ADSL router - it's job is just to run
> multilink ppp, and is rather overspecd,
>
> So, I'm attaching my script, which may make things a bit clearer. This is
> launched from cron with "@reboot".
>
> Anyway, it works fine, except that the screen is blank about half the time.
>
> What I really want is to treat the LCD display like a simple character
> device, into which I can echo text. I appreciate the sophistication of the
> lcdproc architecture, with support for buttons, menus etc, but in this
> particular use-case, I don't need it.
>
> Best wishes,
>
> Richard
>
>
>
> On 01/01/13 23:44, Eric Pooch wrote:
>
>> You need to re-imagine your client rather than the change the server.
>> Your client is spawning 4 processes every 2 seconds. This doesn't
>> seem like a good idea.
>>
>> As a temporary fix, the -t option  for lcdproc_client.py will keep
>> the connection open for the time you specify.  I would change your
>> final sleep command to account for this.
>>
>> --Eric
>>
>> On Jan 1, 2013, at 3:27 PM, Richard Neill wrote:
>>
>>  Dear All,
>>>
>>> I've just joined this list, so please excuse me if I ask an obvious
>>> question.
>>>
>>> I'm trying to get a server status monitor system working,
>>> monitoring a set of parameters of my choice (the lcdproc defaults
>>> aren't suitable for me here)
>>>
>>> So, I have LCDd running   (with a 20x2 picolcd), and found the text
>>> client here:  http://lcdproc-client.**sourceforge.net/<http://lcdproc-client.sourceforge.net/>
>>>
>>> I have a bash-script that sends strings to the client every few
>>> seconds, and they display on the LCD as expected. A simplified
>>> example:
>>>
>>> while : ; do hostname | lcdproc_client.py -f - sleep 1 date  |
>>> lcdproc_client.py -f - sleep 1 done
>>>
>>>
>>> This displays the hostname and the date, alternately, as I expect.
>>>
>>> BUT, between these, every time the python script exits, the system
>>> keeps going back to either the LCDd default screen, or to blank
>>> (the value of ServerScreen).
>>>
>>> How can I get LCDd to just leave the text on screen as it was,
>>> until I explicitly overwrite it?
>>>
>>> Thanks very much,
>>>
>>> Richard
>>>
>>>
>>> P.S. Might I suggest that a "--text" option to lcdproc i.e. "write
>>> this line to screen, and exit" would be really useful in the
>>> default distribution.
>>>
>>>
>>> ______________________________**_________________ LCDproc mailing
>>> list [email protected]
>>> http://lists.omnipotent.net/**mailman/listinfo/lcdproc<http://lists.omnipotent.net/mailman/listinfo/lcdproc>
>>>
>>
>>
>>
>
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#!/usr/bin/env python

# Quick and dirty "Proxy" - Python 3

import socket

s_addr = ('127.0.0.1',50000)
c_addr = ('127.0.0.1',50001)

c = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
c.connect(c_addr) 
c.send('Hello World!'.encode())
    
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(s_addr)
s.listen(5)
print("Listening", s_addr)

while 1:    
    client, address = s.accept()
    print("Connected", address)
    while 1:
    	data = client.recv(1024)
    	if not data:
    		client.close()
    		break
    	print("Read:",data.decode())
    	c.send(data)
    client.close()
    print("Disconnected", address)