pexpect child.before empty for commands executed after connect device

[Bobin Thomas]

Hi all,

I am trying to code a script which will login into HPNA then connect to a device and execute a command and receive the output. Like
Using Python pexpect. Steps inside script I am following is 

1. Using pexpect connect to NA Proxy

2. Execute "Connect <device_ip>"

3. On connected device , execute "show version"

4. Get "show version" output to a variable, using "child.before"

Everything works fine except #4. I am getting nothing as show version output.

But If use same env and script to login/ssh directly  to device and execute the "show version" I get output to my variable child.before.
Also if using script, I login into NA Proxy and execute any local command (for ex : show task) I see child.before output.

Only when script login to NA proxy and then connect to another device and execute command, command output or child.before is blank.

Can someone please help .

 --------------------------- Python Script ~~~~~~~~~~~~~~~~~~~~~~~~

# Connecting to HP NA cli

child = pexpect.spawn('ssh -l %s %s -p %s %s' %(HostTacUser,HostName,ssh_port,SSH_OPTIONS))
child.delaybeforesend = 0.05
child.expect('assword:', timeout=20)

child.sendline(HostTacPass)

child.expect ('NA>')
logfile_prefix = str(time.time());
logfile = "/tmp/ACI_BUG_CHECK_"+logfile_prefix
print "Log File : %s" % logfile
child.logfile = open(logfile, "w")

#Connecting to a Cisco device from HP NA cli

child.sendline('connect 10.1.1.1')

index = child.expect (["[a-z|A-Z|0-9|\-]{3,30}>","]#",pexpect.EOF, pexpect.TIMEOUT], timeout=20)

child.sendline('show version')
index = child.expect (["[a-z|A-Z|0-9|\-]{3,30}>","]#",pexpect.EOF, pexpect.TIMEOUT], timeout=20)

show_out = []
if index == 0:
show_out = child.before.splitlines()

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

but show_out doesnt contain any output

Thanks

Bobin

[Melissa_C_UCMDB · Accepted solution]

Hello,

Please refer to the original thread :

https://community.softwaregrp.com/t5/Network-Automation-User/pexpect-child-before-empty-for-commands-executed-after-connect/td-p/1654981

Regards,