SSH and Windows

[Isaac Raway]

Hello. I'm writing a Python program that connects to servers through
telnetlib to execute a few commands. I've discovered that some of the
servers that I have to connect to with this program run only SSH, so I
need to add support for SSH to the program. I'm looking for a library
that behaves similarly to telnetlib for SSH connections. Does anyone
know of one? I was going to try using pexpect to control the Windows
telnet command, but pexpect only works on Unix.

Any help is appreciated.

[Peter Hansen]

Re: SSH and Windows

Isaac Raway wrote:[color=blue]
>
> Hello. I'm writing a Python program that connects to servers through
> telnetlib to execute a few commands. I've discovered that some of the
> servers that I have to connect to with this program run only SSH, so I
> need to add support for SSH to the program. I'm looking for a library
> that behaves similarly to telnetlib for SSH connections. Does anyone
> know of one? I was going to try using pexpect to control the Windows
> telnet command, but pexpect only works on Unix.[/color]

If it's just to execute a few commands, consider downloading PLink
(from the PuTTY site) and use it via os.system(). It works well.

-Peter

[Isaac Raway]

Re: SSH and Windows

Peter Hansen <peter@engcorp. com> wrote in message news:<3F2069BD. 1FE2EC2@engcorp .com>...[color=blue]
> Isaac Raway wrote:[color=green]
> >
> > Hello. I'm writing a Python program that connects to servers through
> > telnetlib to execute a few commands. I've discovered that some of the
> > servers that I have to connect to with this program run only SSH, so I
> > need to add support for SSH to the program. I'm looking for a library
> > that behaves similarly to telnetlib for SSH connections. Does anyone
> > know of one? I was going to try using pexpect to control the Windows
> > telnet command, but pexpect only works on Unix.[/color]
>
> If it's just to execute a few commands, consider downloading PLink
> (from the PuTTY site) and use it via os.system(). It works well.[/color]

Thank you, it worked perfectly. You have ended a week of headaces.
[color=blue]
> -Peter[/color]

[Fazer]

Re: SSH and Windows

Peter Hansen <peter@engcorp. com> wrote in message news:<3F2069BD. 1FE2EC2@engcorp .com>...[color=blue]
> Isaac Raway wrote:[color=green]
> >
> > Hello. I'm writing a Python program that connects to servers through
> > telnetlib to execute a few commands. I've discovered that some of the
> > servers that I have to connect to with this program run only SSH, so I
> > need to add support for SSH to the program. I'm looking for a library
> > that behaves similarly to telnetlib for SSH connections. Does anyone
> > know of one? I was going to try using pexpect to control the Windows
> > telnet command, but pexpect only works on Unix.[/color]
>
> If it's just to execute a few commands, consider downloading PLink
> (from the PuTTY site) and use it via os.system(). It works well.
>
> -Peter[/color]

Hmm...is there a *nix version for PLink? I checked PuTTY's site and
it's all for Windows. Or maybe an alternative for PLink for *nix?

[Peter Hansen]

Re: SSH and Windows

Fazer wrote:[color=blue]
>
> Peter Hansen <peter@engcorp. com> wrote in message news:<3F2069BD. 1FE2EC2@engcorp .com>...[color=green]
> > Isaac Raway wrote:[color=darkred]
> > >
> > > Hello. I'm writing a Python program that connects to servers through
> > > telnetlib to execute a few commands. I've discovered that some of the
> > > servers that I have to connect to with this program run only SSH, so I
> > > need to add support for SSH to the program. I'm looking for a library
> > > that behaves similarly to telnetlib for SSH connections. Does anyone
> > > know of one? I was going to try using pexpect to control the Windows
> > > telnet command, but pexpect only works on Unix.[/color]
> >
> > If it's just to execute a few commands, consider downloading PLink
> > (from the PuTTY site) and use it via os.system(). It works well.
> >
> > -Peter[/color]
>
> Hmm...is there a *nix version for PLink? I checked PuTTY's site and
> it's all for Windows. Or maybe an alternative for PLink for *nix?[/color]

Maybe try this. Tested (mostly) under Python 1.5.2 (as I recall, under
Linux) and Python 2.0 under Windows:

import sys
import os
import time

True, False = 1, 0

class SshException(Ex ception): pass

class LinuxSshSession :

PAT_PASSWORD = '[pP]assword:'

def __init__(self, host, user, password, timeout=30):
self.host = host
self.user = user
self.password = password
self.timeout = timeout
self.verbose = True

def scp(self, src, dest):
import pexpect
user = self.user
host = self.host

if self.verbose:
sys.stdout.writ e('scp %(src)s %(user)s@%(host )s:%(dest)s ...' % locals())
sys.stdout.flus h()
began = time.time()

try:
# use compression (not that that would help with a .tgz file
# and make sure we don't get messed up by the known_hosts file
child = pexpect.spawn(' scp -C'
' -o UserKnownHostsF ile=/dev/null'
' -o StrictHostKeyCh ecking=no'
' %(src)s %(user)s@%(host )s:%(dest)s' % locals())
state = 'authorizing'
while 1:
#~ print '%s: %r///%r' % (state, child.before, child.after)
if state == 'authorizing':
match = child.expect([pexpect.EOF, pexpect.TIMEOUT , self.PAT_PASSWO RD],
timeout=self.ti meout)
if match == 0:
raise SshException('f ailed to authenticate')
elif match == 1:
raise SshException('t imeout waiting to authenticate')
elif match == 2:
child.sendline( self.password)
state = 'copying'

elif state == 'copying':
match = child.expect([pexpect.EOF, pexpect.TIMEOUT , 'stalled', 'ETA'],
timeout=self.ti meout)
if match == 0:
break
elif match == 1:
raise SshException('t imeout waiting for response')
elif match == 2:
state = 'stalled'

elif state == 'stalled':
match = child.expect([pexpect.EOF, pexpect.TIMEOUT , 'ETA'],
timeout=self.ti meout)
if match == 0:
break
elif match == 1:
import pdb
pdb.set_trace()
raise SshException('s talled for too long, aborted copy')
elif match == 2:
state = 'copying'

finally:
if self.verbose:
elapsed = time.time() - began
try:
size = os.stat(src)[os.path.stat.ST _SIZE]
rate = size / elapsed
sys.stdout.writ e(' %.1fs (%d cps)\n' % (elapsed, rate))
except:
sys.stdout.writ e(' %.1fs\n' % (elapsed))


def ssh(self, cmd):
import pexpect
user = self.user
host = self.host

if self.verbose:
sys.stdout.writ e('ssh -l %(user)s %(host)s \"%(cmd)s\"\ n' % locals())
sys.stdout.flus h()

# use compression
# -o options make sure we don't get messed up by the known_hosts file
child = pexpect.spawn(' ssh -C'
' -o UserKnownHostsF ile=/dev/null'
' -o StrictHostKeyCh ecking=no'
' -l %(user)s %(host)s '
'\"%(cmd)s\"' % locals())
state = 'authorizing'
while 1:
if state == 'authorizing':
match = child.expect([pexpect.EOF, pexpect.TIMEOUT , self.PAT_PASSWO RD],
timeout=self.ti meout)
if match == 0:
raise SshException('f ailed to authenticate')
elif match == 1:
raise SshException('t imeout waiting to authenticate')
elif match == 2:
child.sendline( self.password)
state = 'running'

elif state == 'running':
match = child.expect([pexpect.EOF, pexpect.TIMEOUT],
timeout=self.ti meout)
if match == 0:
break
elif match == 1:
raise SshException('t imeout waiting to finish')

return child.before


class WindowsSshSessi on:
def __init__(self, host, user, password, timeout=30):
self.host = host
self.user = user
self.password = password

def scp(self, src, dest):
user = self.user
host = self.host
password = self.password
return os.system('pscp -pw %(password)s %(src)s %(user)s@%(host )s:%(dest)s' % locals())

def ssh(self, cmd):
user = self.user
host = self.host
password = self.password
os.system('plin k -pw %(password)s -ssh %(user)s@%(host )s "%(cmd)s"' % locals())


def SshSession(host , user, password, timeout=30):
if sys.platform == 'win32':
sessionClass = WindowsSshSessi on
else:
# assume we're on linux if platform is not windows
sessionClass = LinuxSshSession
return sessionClass(ho st, user, password, timeout)


-Peter

[Peter Hansen]

Re: SSH and Windows

Peter Hansen wrote:[color=blue]
>
> Maybe try this. Tested (mostly) under Python 1.5.2 (as I recall, under
> Linux) and Python 2.0 under Windows:
>
> elif state == 'stalled':
> match = child.expect([pexpect.EOF, pexpect.TIMEOUT , 'ETA'],
> timeout=self.ti meout)
> if match == 0:
> break
> elif match == 1:
> import pdb
> pdb.set_trace()
> raise SshException('s talled for too long, aborted copy')[/color]

Ugh... remove the "import pdb" and subsequent pdb.set_trace() before attempting
to use the above... sorry about that. Must have checked a debugging version
in to CVS. :-(

-Peter