Inconsistent output with write_channel and read_channel

Thanks again for the help on https://github.com/ktbyers/netmiko/issues/1315

I am using write_channel and read_channel to parse the possible subcommands for all commands in a router.

I wrote this function below

def getCommandsList(input_cmd):
    res = []
    print('cmd = show {} ?'.format(input_cmd))
    net_connect.write_channel("show {} ?".format(input_cmd))
    time.sleep(0.5)
    output = net_connect.read_channel()
    output = output.split('\n')
    for i in range(len(output)):
        if i != 0 and i != len(output) - 1: # skip first and last since they are not commands
            line = output[i]
            line = line.lstrip()
            cmd, description = line.split(' ', 1)
            description = description.lstrip().replace('\r', '')
            print(cmd, description)
            res.append(str(cmd))
    return res

and for a single run, it works great.

Input: 'aaa' (show aaa ?)
Output: ['ikegroup', 'locald', 'login', 'password-policy', 'sync', 'task', 'taskgroup', 'trace', 'userdb', 'usergroup']

However, if I run it continuously, it gives me a weird output

Input: 'aaa ikegroup' (show aaa ikegroup)
Error:
Traceback (most recent call last):
  File "parse.py", line 50, in <module>
    print(getCommandsList('aaa ikegroup'))
  File "parse.py", line 35, in getCommandsList
    cmd, description = line.split(' ', 1)
ValueError: need more than 1 value to unpack

and when I print out the output, it gives me

[u'show aaa ikegroup ?\r', u'\r ^\r', u"% Invalid input detected at '^' marker.\r", u'RP/0/RP1/CPU0:FRETTA-1#show aaa show aaa ikegroup ']

So, it seems like the output is inconsistent.

I am trying to do it recursively, but if the output is inconsistent, it will be very hard to do it.

Any help?

===========MORE INFO================

I tried to do this just to see the pattern of output:

net_connect.write_channel("show {} ?".format('aaa'))
time.sleep(0.5)
output = net_connect.read_channel()
print(output)
print('-------------')
net_connect.write_channel("show {} ?".format('aaa'))
time.sleep(0.5)
output = net_connect.read_channel()
print(output)
print('-------------')
net_connect.write_channel("show {} ?".format('aaa'))
time.sleep(0.5)
output = net_connect.read_channel()
print(output)
print('-------------')

this shows

-bash-4.2# python parse2.py
show aaa ?
  ikegroup         Show local IKE group(s)
  locald           locald sub system(cisco-support)
  login            login sub system
  password-policy  Show all the password policies configured in the system
  sync             aaa_lib_sync sub system(cisco-support)
  task             Show task information
  taskgroup        Show all the local taskgroups configured in the system
  trace            Show trace data for AAA sub system
  userdb           Show all local users with the usergroups each belong to
  usergroup        Show all the local usergroups configured in the system
RP/0/RP1/CPU0:FRETTA-1#show aaa
-------------
show aaa ?
                                 ^
% Invalid input detected at '^' marker.
RP/0/RP1/CPU0:FRETTA-1#show aaa show aaa
-------------
show aaa ?
                                 ^
% Invalid input detected at '^' marker.
RP/0/RP1/CPU0:FRETTA-1#show aaa show aaa show aaa
-------------

So it seems like I need a way to completely clear my input when I use the next write_channel.

[whyjay17]

@ktbyers Thanks again!

[ktbyers]

You will have to figure out what they translate to in terms of ASCII and then send that character code using write_channel.