Re: [pysnmp-users] pysnmp / pyasn1 decode problem with multi-line traps

[Ilya E. <il...@gl...>]

That's right, .asOctets() is only defined for OctetString type and its 
subclasses. Therefore, to deal with octets of OctetString() you should 
do additional check:

from pysnmp.proto.rfc1902 import OctetString

...

if isinstance(val, OctetString):
     val = val.asOctets()

Keep in mind that octet string is not always the same as printable 
string. The former is not immune to your terminal potentially eating 
non-printable characters or garbling output in a funny way. Also, text 
encoding is not defined by OctetString. To be on a safe side default 
OctetString printout is done in hex whenever a non-printable is seen in 
its contents.

-ilya

On 03/11/2015 03:18 PM, Craig Small wrote:
> On Wed, Mar 11, 2015 at 07:02:44AM +0100, Tom wrote:
>>     ;AttributeError: ObjectSyntax instance has no attribute 'asOctets'
> Are you sure each row is returning something asOctets makes sense for?
> An Integer doesn't make sense.
>
>>     Does it only works if a hex value is send by snmp?
> I believe it works for certain types of values, such as an OctetString
>
>>     How can I check if the value is hex or not?
> Not sure, but the types are found in pyasn1.type.univ so you could
> compare it to, say, univ.OctetString
>
> ObjectSyntax seems to be the superset of all types, from what I can tell
> it means pysnmp wasn't sure what the type should be.
>
> It's been an interesting and educational discussion anyhow.
>
>   - Craig