I sent a message to this forum nearly two weeks ago asking for hints about how
to convert a particular MUMPS construct into a Perl construct. I recevied
several helpful answers and have been able to implement a solution. I'd like
to thank everyone who kindly took the time to respond. Here is the solution I
have implemented:
The application in question is an SNMP program that is querying routers and
switches for various data. A number of SNMP variables, or Object Identifiers
(OIDs), are placed into an SNMP message and a GetBulk query is sent to the
device in question. The returned answer is placed in a hash that has all the
descendants of the OIDs as the key and the contents of the OIDs as the value.
There may be 10 entries returned, there may be 1000, but the large sized
returns are rare and they don't get much bigger. The problem I was trying to
resolve was how to take each of the original OIDs and find all of their
descendants in the hash. Answer:
A single for loop is executed against the sorted hash (the Net::SNMP module
provides a means to lexically sort SNMP OIDs). An array is built with each key
found. A second hash is also built that has the original OIDs as its keys and
the starting and ending points within the array of the descendants of that OID.
I am able to duplicate everything I was doing with the MUMPS $ORDER function by
using this construct. Here is a brief example:
Original OIDs in the SNMP query:
$ifDescr = '1.3.6.1.2.1.2.2.1.2';
$ifInOctets = '1.3.6.1.2.1.2.2.1.10';
$ifOutOctets = '1.3.6.1.2.1.2.2.1.16';
Resulting answer in hash (after sorting):
1.3.6.1.2.1.2.2.1.2.1 => FastEthernet0/0
1.3.6.1.2.1.2.2.1.2.2 => FastEthernet0/1
1.3.6.1.2.1.2.2.1.2.3 => FastEthernet0/1/0
1.3.6.1.2.1.2.2.1.2.4 => FastEthernet0/1/1
1.3.6.1.2.1.2.2.1.2.5 => FastEthernet0/1/2
1.3.6.1.2.1.2.2.1.2.6 => FastEthernet0/1/3
1.3.6.1.2.1.2.2.1.2.7 => Serial0/2/0
1.3.6.1.2.1.2.2.1.2.8 => Serial0/2/1
1.3.6.1.2.1.2.2.1.2.10 => Null0
1.3.6.1.2.1.2.2.1.2.11 => Vlan1
1.3.6.1.2.1.2.2.1.2.14 => Tunnel1
1.3.6.1.2.1.2.2.1.2.15 => Dialer1
1.3.6.1.2.1.2.2.1.2.16 => Tunnel207
1.3.6.1.2.1.2.2.1.2.17 => Tunnel1000
1.3.6.1.2.1.2.2.1.2.18 => Loopback7
1.3.6.1.2.1.2.2.1.10.1 => 874730985
1.3.6.1.2.1.2.2.1.10.2 => 1811311832
1.3.6.1.2.1.2.2.1.10.3 => 0
1.3.6.1.2.1.2.2.1.10.4 => 0
1.3.6.1.2.1.2.2.1.10.5 => 0
1.3.6.1.2.1.2.2.1.10.6 => 0
1.3.6.1.2.1.2.2.1.10.7 => 0
1.3.6.1.2.1.2.2.1.10.8 => 0
1.3.6.1.2.1.2.2.1.10.10 => 810178717
1.3.6.1.2.1.2.2.1.10.11 => 0
1.3.6.1.2.1.2.2.1.10.14 => 7028243
1.3.6.1.2.1.2.2.1.10.15 => 976914585
1.3.6.1.2.1.2.2.1.10.16 => 2208958682
1.3.6.1.2.1.2.2.1.10.17 => 330703546
1.3.6.1.2.1.2.2.1.10.18 => 0
1.3.6.1.2.1.2.2.1.16.1 => 2555943293
1.3.6.1.2.1.2.2.1.16.2 => 1303511954
1.3.6.1.2.1.2.2.1.16.3 => 0
1.3.6.1.2.1.2.2.1.16.4 => 0
1.3.6.1.2.1.2.2.1.16.5 => 0
1.3.6.1.2.1.2.2.1.16.6 => 0
1.3.6.1.2.1.2.2.1.16.7 => 0
1.3.6.1.2.1.2.2.1.16.8 => 0
1.3.6.1.2.1.2.2.1.16.10 => 0
1.3.6.1.2.1.2.2.1.16.11 => 0
1.3.6.1.2.1.2.2.1.16.14 => 27898498
1.3.6.1.2.1.2.2.1.16.15 => 679742996
1.3.6.1.2.1.2.2.1.16.16 => 1497913589
1.3.6.1.2.1.2.2.1.16.17 => 329425921
1.3.6.1.2.1.2.2.1.16.18 => 43584486
These keys are then placed in an array indexed from 0 to n. The "original OID"
hash then looks like the following:
$OID{$ifDescr} = "0,17"
$OID{$ifInOctets} = "18,35"
$OID{$ifOutOctets} = "36,53"
I can now find the answers for each variable I queried, from the beginning
forward or the end backward, with only one scan of the hash table.
Thanks again, everyone.
One final note:
I did take a look at Language-Mumps-1.07. This is based on a very old,
primitive flavor of MUMPS and, when I wrote a very small test program and
ran it agains this "translator" it returned the wrong results. I don't
recommend anyone using it.
Mark Berryman
