Getting readable results from Net::SNMP get_table method

[fingers]

I am trying write a script that will poll cisco gear for information regarding it's CDP neighbors.

I had pretty much completed the project using telnet to get the information I wanted when I realized it would be quicker and less intrusive to gather this info with SNMP. I tracked down the appropriate oid and am using the Net::SNMP get_table method. It seems to be working, but I am getting output that looks like this:

HASH(0x82753ec)

What do I need to do to extract some meaningful information from this?

I have read the docs on the Net::SNMP module and am feeling very obtuse right now. I would love to see some actual examples of the get_table method if anyone has any existing code that uses it.

This is the pretty bare bones code I am using to test this method.

#!/usr/bin/perl -w
use Net::SNMP;
# requires a hostname and a community string as its arguments
($session,$error) = Net::SNMP->session(Hostname => $ARG[0], Community 
+=> $ARGV[1]);
die "session error: $error" unless ($session);
#1.3.6.1.4.1.9.9.23.1.2.1.1 is the OID that the CDP info starts at
$result = $session->get_table("1.3.6.1.4.1.9.9.23.1.2.1.1");
die "request error: ".$session->error unless (defined $result);
print "$result \n";
$session->close;

Thanks in advance on any light you can shine on this. I do believe that my eyes will start bleeding if I stare at any more docs.

[Ovid]

Data::Dumper is a quick and easy method of seeing what's really in variables. In this case, the scalar $result appears to be a reference to an anonymous hash. Try this:

use Data::Dumper;
print Dumper( $result );

That will let you see what you're getting back.

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.

[srawls]

Whenever you see code like this: HASH(0x82753ec) then you are referencing the entire hash, this is obviosly not what you want, so try this:

print "$result{$_}\n" for keys $result;

I am not familiar with the module you are using, but I think this code should work; if you have any more questions - just ask.

UPDATE: Thanks Ovid, I missed that one.

The 15 year old, freshman programmer,
Stephen Rawls

[Ovid]

Close, but here's what you actually want.

print "$result->{$_}\n" for keys %$result;

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.

[fingers]

When I use

print "$result->{$_}\n" for keys %$result;

I get output that looks like

HASH(0x82a08e0)->(1.3.6.1.4.9.9.23.1.2.1.1.8.4.2)

when I use the Data::Dumper module you suggest I get results that look like.

'1.3.6.1.4.9.9.23.1.2.1.1.8.4.2' => 'WS-C6509'

I assume that the oid is the key and the WS-C6509 is the object in the hash.

How would I pull that all into hash that I would be able to manipulate?

[fingers]

Now that I can print out the entire hash and I know that I'm getting the data that I eventually want to use. I am stuck at trying to figure out how to access values in my hash without knowing exactly what the keys are.

[dws]

I am stuck at trying to figure out how to access values in my hash without knowing exactly what the keys are.

@values = values %hash;

[Anonymous Monk]

after giving oid can i use grep in get_table

[mr.nick]

(deleted)

Bzzzt! Sorry, I messed up. I'm not sure what I was thinking.