hashing it out.

penguinfuz has asked for the wisdom of the Perl Monks concerning the following question:

Currently I am pushing certain values into an array, but I think my goal would be best accomplished by populating a hash with values from another hash and a `back-tick` command.

The first hash is a Value=>Label which I loop over pushing "Label" into another hash as the key and passing the "Value" to a back-tick command, to be used as the associated keys value. I hope that makes sense. ;)

Here is a snippet of where I am at:

$direction = shift;
%iface = (
          "if${direction}Octets.2"   => 'FastEthernet0/1',
          "if${direction}Octets.3"   => 'FastEthernet0/2',
          "if${direction}Octets.4"   => 'FastEthernet0/3',
          "if${direction}Octets.5"   => 'FastEthernet0/4',
          "if${direction}Octets.26"  => 'GigabitEthernet0/1',
  );

foreach my $oid (sort keys(%iface)) {
  %oids = ("$iface{$oid}" => `$snmpwalk $ip $community $oid`);
}
[download]

The %oids hash seems to be overwriten with each loop, leading me to re-think the process. I was previously pushing the above data onto an array, but I need to keep the label and 'return values' together for later pushing into a db.

I was thinking of another variation on the loop, something like:

foreach my $oid (sort keys(%iface)) {
  @oids = ({"$iface{$oid}" => `$snmpwalk $ip $community $oid`});
}
[download]

However, I am not exactly sure how to get the data pairs back out of the @oids array. Can anyone nudge me in the right direction?

Comment on hashing it out. Select or Download Code

Replies are listed 'Best First'.
Re: hashing it out. by graff (Chancellor) on May 10, 2002 at 22:19 UTC
If I understand you right (??), I think you're just using the wrong syntax for the hash assignment inside the foreach. Instead of this: foreach my $oid (sort keys(%iface)) { %oids = ("$iface{$oid}" => `$snmpwalk $ip $community $oid`); } [download] I think you want this: foreach my $oid (sort keys(%iface)) { $oids{$iface{$oid}} = `$snmpwalk $ip $community $oid`; } [download] because I think your description said something to the effect of "keys of %iface are used as parameters in a set of back-tick operations, and values of %iface are then used as keys of of %oids -- the values in %oids are the strings returned by the back-ticks." (I'm not asserting that this is any clearer than your own description, but if you get what I mean, then I must have gotten what you meant.)	[reply] [d/l] [select]
Re: Re: hashing it out. by penguinfuz (Pilgrim) on May 15, 2002 at 17:05 UTC
> ...I think your description said something to the effect... > ...if you get what I mean, then I must have gotten what you meant. I think you understand my goal precisely; However, I'm not sure your suggestion will work either. After an initial attempt it did not work but I will continue thinking on it, but for now I am simply pushing the data into an array: foreach my $oid (sort keys(%iface)) { push @oids,"$iface{$oid}: ",`$snmpwalk $ip $community $oid`; } [download] Not exactly what I want, so I think I will look into Net::SNMP now and revisit the issue when my "hash" skills are a bit stronger. ;) Cheers.	[reply] [d/l]
Re: hashing it out. by Anonymous Monk on May 10, 2002 at 22:17 UTC
It sounds like you might be looking for this: %oids = ( ); foreach my $oid ( sort keys %iface ) { $oids{$iface{$oid}} = `$snmpwalk $ip $community $oid`; }; [download] Does that help? -Jules K.	[reply] [d/l]
Re: hashing it out. by lshatzer (Friar) on May 10, 2002 at 22:45 UTC
Unrelated to your question, but I like to advocate it's use. Use qx as oppsed to `backticks`. To me it is easier to read, and know what is going on, then backticks. At least with certian fonts.	[reply]
Re: hashing it out. by dsheroh (Monsignor) on May 11, 2002 at 13:53 UTC
If I read your question correctly, and you want to store multiple oids for each iface, then you'd probably be best off using a hash of arrays.	[reply]
Re: hashing it out. by yodabjorn (Monk) on May 11, 2002 at 10:43 UTC
Not a direct answer, but instead of using ticks and snmpwalk is this somthing that can be handled with Net::SNMP(CPAN). There seems to be a lot of data on PM about using Net::SNMP(Perlmonks)	[reply]
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