Convert snmp octet string to human readable date format

Question

Using the pysnmp framework i get some values doing a snmp walk. Unfortunately for the oid

1.3.6.1.21.69.1.5.8.1.2 (DOCS-CABLE-DEVICE-MIB)

Answer 1

@Paulo Scardine: This was the best answer I found online when working to resolve a very similar problem. It still took me a little while to resolve my issue even with this answer, so I wanted to post a follow up answer that may add more clarity. (specifically the issue with the date having different length options).

The following piece of code connects to a server and grabs the system time and then outputs it as a string to illustrate the method.

import netsnmp
import struct
oid = netsnmp.Varbind('hrSystemDate.0')
resp = netsnmp.snmpget(oid, Version=1, DestHost='', Community='public')
oct = str(resp[0])
# hrSystemDate can be either 8 or 11 units in length.
oct_len = len(oct)
fmt_mapping = dict({8:'>HBBBBBB', 11:'>HBBBBBBcBB'})
if oct_len == 8 or oct_len == 11:
    t = struct.unpack(fmt_mapping[oct_len], oct)
    print 'date tuple: %s' % (repr(t))
else:
    print 'invalid date format'

I hope this helps other people who are having similar issues trying to work with this type of data.