Client/Server Question

[diffuser78@gmail.com]

My server.py looks like this

---------------------------------------------CODE----------------------------------
#!/usr/bin/env python
import socket
import sys
import os

s = socket.socket(s ocket.AF_INET, socket.SOCK_STR EAM)
host = ''
port = 2000

s.bind((host,po rt))
s.listen(1)
conn, addr = s.accept()
print 'client is at', addr

while True:
data = conn.recv(10000 00)
if (data == 'MaxSim'):
print 'MaxiSim'
os.system('note pad')
elif (data == 'Driving Sim'):
print 'Driving Sim'
os.system('expl orer')
elif (data == 'SHUTDOWN'):
print 'Shutting down...'
os.system('shut down -s')
conn.close()
break
-------------------------------------------CODE
END-------------------------------------

I am running this above program on a windows machine. My client is a
Linux box. What I want to achieve is that server.py should follows
instructions till I send a 'SHUTDOWN' command upon which it should shut
down.

When I run this program and suppose send 'MaxSim' to it, it launches
notepad.exe fine, but then after that it doesn't accept subsequent
command. I want is that it should accept subsequent commands like
Driving Sim and launch windows explorer etc untill I send a 'SHUTDOWN'
command.

Any help on this, it will be greatly appreciated.

[Dennis Benzinger]

Re: Client/Server Question

diffuser78@gmai l.com wrote:

My server.py looks like this
>
---------------------------------------------CODE----------------------------------
#!/usr/bin/env python
import socket
import sys
import os
>
s = socket.socket(s ocket.AF_INET, socket.SOCK_STR EAM)
host = ''
port = 2000
>
s.bind((host,po rt))
s.listen(1)
conn, addr = s.accept()
print 'client is at', addr
>
while True:
data = conn.recv(10000 00)
if (data == 'MaxSim'):
print 'MaxiSim'
os.system('note pad')
elif (data == 'Driving Sim'):
print 'Driving Sim'
os.system('expl orer')
elif (data == 'SHUTDOWN'):
print 'Shutting down...'
os.system('shut down -s')
conn.close()
break
-------------------------------------------CODE
END-------------------------------------
>
I am running this above program on a windows machine. My client is a
Linux box. What I want to achieve is that server.py should follows
instructions till I send a 'SHUTDOWN' command upon which it should shut
down.
>
When I run this program and suppose send 'MaxSim' to it, it launches
notepad.exe fine, but then after that it doesn't accept subsequent
command. I want is that it should accept subsequent commands like
Driving Sim and launch windows explorer etc untill I send a 'SHUTDOWN'
command.
>
Any help on this, it will be greatly appreciated.
>

os.system() blocks until the called program has finished. Use the
subprocess module <http://docs.python.org/lib/module-subprocess.html >:

<untested_cod e>

import subprocess

subprocess.Pope n("notepad")

</untested_code>


Dennis

[diffuser78@gmail.com]

Re: Client/Server Question

Is os.system() going to be deprecated in future ?.....I read somewhere.

Dennis Benzinger wrote:

diffuser78@gmai l.com wrote:

My server.py looks like this

---------------------------------------------CODE----------------------------------
#!/usr/bin/env python
import socket
import sys
import os

s = socket.socket(s ocket.AF_INET, socket.SOCK_STR EAM)
host = ''
port = 2000

s.bind((host,po rt))
s.listen(1)
conn, addr = s.accept()
print 'client is at', addr

while True:
data = conn.recv(10000 00)
if (data == 'MaxSim'):
print 'MaxiSim'
os.system('note pad')
elif (data == 'Driving Sim'):
print 'Driving Sim'
os.system('expl orer')
elif (data == 'SHUTDOWN'):
print 'Shutting down...'
os.system('shut down -s')
conn.close()
break
-------------------------------------------CODE
END-------------------------------------

I am running this above program on a windows machine. My client is a
Linux box. What I want to achieve is that server.py should follows
instructions till I send a 'SHUTDOWN' command upon which it should shut
down.

When I run this program and suppose send 'MaxSim' to it, it launches
notepad.exe fine, but then after that it doesn't accept subsequent
command. I want is that it should accept subsequent commands like
Driving Sim and launch windows explorer etc untill I send a 'SHUTDOWN'
command.

Any help on this, it will be greatly appreciated.

>
>
os.system() blocks until the called program has finished. Use the
subprocess module <http://docs.python.org/lib/module-subprocess.html >:
>
<untested_cod e>
>
import subprocess
>
subprocess.Pope n("notepad")
>
</untested_code>
>
>
Dennis

[faulkner]

Re: Client/Server Question

i highly doubt it.

http://www.google.com/search?domains=www.python.org&sitesearch=www.python.org&sourceid=google-search&q=os+system+deprecate&submit=search

diffuser78@gmai l.com wrote:

Is os.system() going to be deprecated in future ?.....I read somewhere.
>
Dennis Benzinger wrote:

diffuser78@gmai l.com wrote:

My server.py looks like this
>
---------------------------------------------CODE----------------------------------
#!/usr/bin/env python
import socket
import sys
import os
>
s = socket.socket(s ocket.AF_INET, socket.SOCK_STR EAM)
host = ''
port = 2000
>
s.bind((host,po rt))
s.listen(1)
conn, addr = s.accept()
print 'client is at', addr
>
while True:
data = conn.recv(10000 00)
if (data == 'MaxSim'):
print 'MaxiSim'
os.system('note pad')
elif (data == 'Driving Sim'):
print 'Driving Sim'
os.system('expl orer')
elif (data == 'SHUTDOWN'):
print 'Shutting down...'
os.system('shut down -s')
conn.close()
break
-------------------------------------------CODE
END-------------------------------------
>
I am running this above program on a windows machine. My client is a
Linux box. What I want to achieve is that server.py should follows
instructions till I send a 'SHUTDOWN' command upon which it should shut
down.
>
When I run this program and suppose send 'MaxSim' to it, it launches
notepad.exe fine, but then after that it doesn't accept subsequent
command. I want is that it should accept subsequent commands like
Driving Sim and launch windows explorer etc untill I send a 'SHUTDOWN'
command.
>
Any help on this, it will be greatly appreciated.
>

os.system() blocks until the called program has finished. Use the
subprocess module <http://docs.python.org/lib/module-subprocess.html >:

<untested_cod e>

import subprocess

subprocess.Pope n("notepad")

</untested_code>


Dennis

[faulkner]

Re: Client/Server Question

you might want to look at sshd. if you're on a windows box, you may
need cygwin. if you're on linux, you either already have it, or it's in
your package manager.

diffuser78@gmai l.com wrote:

My server.py looks like this
>
---------------------------------------------CODE----------------------------------
#!/usr/bin/env python
import socket
import sys
import os
>
s = socket.socket(s ocket.AF_INET, socket.SOCK_STR EAM)
host = ''
port = 2000
>
s.bind((host,po rt))
s.listen(1)
conn, addr = s.accept()
print 'client is at', addr
>
while True:
data = conn.recv(10000 00)
if (data == 'MaxSim'):
print 'MaxiSim'
os.system('note pad')
elif (data == 'Driving Sim'):
print 'Driving Sim'
os.system('expl orer')
elif (data == 'SHUTDOWN'):
print 'Shutting down...'
os.system('shut down -s')
conn.close()
break
-------------------------------------------CODE
END-------------------------------------
>
I am running this above program on a windows machine. My client is a
Linux box. What I want to achieve is that server.py should follows
instructions till I send a 'SHUTDOWN' command upon which it should shut
down.
>
When I run this program and suppose send 'MaxSim' to it, it launches
notepad.exe fine, but then after that it doesn't accept subsequent
command. I want is that it should accept subsequent commands like
Driving Sim and launch windows explorer etc untill I send a 'SHUTDOWN'
command.
>
Any help on this, it will be greatly appreciated.

[Dennis Benzinger]

Re: Client/Server Question

diffuser78@gmai l.com wrote:

Is os.system() going to be deprecated in future ?.....I read somewhere.
[...]

Sometime in the future it will. But that won't happen soon. Read the
second paragraph of "Backwards Compatibility" in the subprocess PEP
<http://www.python.org/dev/peps/pep-0324/>.


Dennis

[bryanjugglercryptographer@yahoo.com]

Re: Client/Server Question


diffuser78@gmai l.com wrote:

My server.py looks like this
>
---------------------------------------------CODE----------------------------------
#!/usr/bin/env python
import socket
import sys
import os
>
s = socket.socket(s ocket.AF_INET, socket.SOCK_STR EAM)
host = ''
port = 2000
>
s.bind((host,po rt))
s.listen(1)
conn, addr = s.accept()
print 'client is at', addr
>
while True:
data = conn.recv(10000 00)
if (data == 'MaxSim'):
print 'MaxiSim'
os.system('note pad')
elif (data == 'Driving Sim'):
print 'Driving Sim'
os.system('expl orer')
elif (data == 'SHUTDOWN'):
print 'Shutting down...'
os.system('shut down -s')
conn.close()
break
-------------------------------------------CODE
END-------------------------------------
>
I am running this above program on a windows machine. My client is a
Linux box. What I want to achieve is that server.py should follows
instructions till I send a 'SHUTDOWN' command upon which it should shut
down.
>
When I run this program and suppose send 'MaxSim' to it, it launches
notepad.exe fine, but then after that it doesn't accept subsequent
command.

As others noted, that's because os.system() blocks.
You have more bugs than that.

The recv() might return "MaxiSimDri ving Sim". It could return
"MaxiS" on one call, and "im" on the next. If the remote side
closes the connection, recv() will keep returning the empty
string, and your program will be stuck in an infinite loop.

Did you understand Faulkner's suggustion? Anyone who connects to
TCP port 2000 can invoke "shutdown -s" (which I assume shuts down
your host).


--
--Bryan

[diffuser78@gmail.com]

Re: Client/Server Question

The subprocess module didn't work here. I tried using os.popen(), that
won't help it either.


What I am trying to achieve is that the server daemon is sitting and
listening to command from the client. As client send "MaxSim" it
launches MaxSim.exe and then again waits for subsequent commands.
Support client sends "DrivingSim " it should launch DrivingSim.exe etc.
It does till client sends a "SHUTODWN" message upon which it shuts down
itself.

Any pointers to achieve this more seamlessly.

Every help is greatly appreciated.

Thanks


Dennis Benzinger wrote:

os.system() blocks until the called program has finished. Use the
subprocess module <http://docs.python.org/lib/module-subprocess.html >:
>
<untested_cod e>
>
import subprocess
>
subprocess.Pope n("notepad")
>
</untested_code>
>
>
Dennis

[diffuser78@gmail.com]

Re: Client/Server Question

The recv() might return "MaxiSimDri ving Sim". It could return
"MaxiS" on one call, and "im" on the next. If the remote side
closes the connection, recv() will keep returning the empty
string, and your program will be stuck in an infinite loop.

How to overcome this problem ?

Did you understand Faulkner's suggustion? Anyone who connects to
TCP port 2000 can invoke "shutdown -s" (which I assume shuts down
your host).

I did, anyone who connects to port 2000 might be able to send a
shutdown and close the computer. I am aware that its not the best way
to achieve this but my app runs on a small network without actually
connecting to internet.

Can you give any tips to overcome the above mentioned problem.

--Bryan

[diffuser78@gmail.com]

Re: Client/Server Question

I apologize.

subprocess did work for me like a charm I made a mistake in my code.
Appreciate your help.

Dennis Benzinger wrote:

os.system() blocks until the called program has finished. Use the
subprocess module <http://docs.python.org/lib/module-subprocess.html >:
>
<untested_cod e>
>
import subprocess
>
subprocess.Pope n("notepad")
>
</untested_code>
>
>
Dennis