Perl

dcarrington · 04-11-2012, 06:04 PM

Hello,

I'm trying to write a script to clean up my RH Satellite repositories so I can get rid of a lot of the old rpm's that are taking up space.

Most of the API's that I've been looking up are functioning as I would expect. However, some are not.

For example, I'm trying to identify what channel a package is in. There is an API called listProvidingChannels that seems like it might be useful, but when I use it, I can't seem to get any useful information out of it.

I've got an open session set up in the code already and I run the following line:

Quote:

my $channels = $client->call('packages.listProvidingChannels', $session, $packageid);

When I try to get information out of $channels, however, I can't get anything useful.

Any reference to $channels->{'name'} gives me the following errors:

Quote:

Pseudo-hashes are deprecated at ./cleansat.pl line 53, <> line 4.
Argument "\x{52}\x{65}..." isn't numeric in hash element at ./cleansat.pl line 53, <> line 4.
Bad index while coercing array into hash at ./cleansat.pl line 53, <> line 4.

If I simply do:

Quote:

print "$channels\n";

I get

Quote:

ARRAY(0x94ae35c)

Not sure where to find more information about these API's (this one specifically). Other API's that I use the same type of syntax for work as one would expect. For example, I have a line:

Quote:

my $latestpackages = $client->call('channel.software.listLatestPackages', $session, $chan);

If I reference $latestpackages->{'name'}, I get "acl" for example. If I reference $latestpackages->{'id'}, I get "54079" and so on.

Does anyone know more about this? Or know where I can find better, more detailed information?

Thanks!!!

CTM · 04-11-2012, 06:17 PM

Use Data::Dumper (one of the Perl core modules) to recursively dump data structures:

Code:

print Dumper($channels), "\n";

If $channels is an object, it'll give you the class name so you can look up the code for that package and figure out what it represents.

dcarrington · 04-11-2012, 06:27 PM

CTM,

Awesome! I'll give that a try. Been banging my head on this one for the last three hours.

dcarrington · 04-11-2012, 06:32 PM

Nope. Unfortunately, that did not work:

Quote:

Undefined subroutine &main::Dumper called at ./cleansat.pl line 53, <> line 4.

dcarrington · 04-11-2012, 06:37 PM

Never mind....I missed the reference to 'Use Data:

umper;' at the top of the post.

That did give me more info. Now to see if I can figure out why I can't get at it inside the code.

CTM · 04-11-2012, 06:46 PM

The syntax that Data::Dumper uses in its output will give you some hints about how to use the data structure - although I don't use Red Hat myself, if you paste the output here I might be able to give you a push in the right direction

dcarrington · 04-11-2012, 06:55 PM

CTM,

I added a Dumper call with one of the other similar calls (the listLatestPackages one mentioned earlier) and the structure seems pretty much exactly the same...just different entries..but same format.

The one below is the one that's failing.

Quote:

$VAR1 = [
{
'parent_label' => ' ',
'name' => 'Red Hat Enterprise Linux Server (v. 6 for 64-bit x86_64)',
'label' => 'rhel-x86_64-server-6'
}
];

Pseudo-hashes are deprecated at ./cleansat.pl line 59, <> line 4.
Argument "\x{72}\x{68}..." isn't numeric in hash element at ./cleansat.pl line 59, <> line 4.
Bad index while coercing array into hash at ./cleansat.pl line 59, <> line 4.

CTM · 04-11-2012, 07:04 PM

Okay, the data structure you dumped is an arrayref ([]) of hashrefs ({}), so I assume it represents a list of available channels (I don't know any RHEL-specific terminology so I'm not sure what a "channel" really is). You can iterate over the arrayref in the usual way, but remember to dereference the arrayref before operating on it as if it were an array:

Code:

foreach my $channel (@{$channels}) {
    print $channel->{name}, "\n";
}

dcarrington · 04-12-2012, 10:01 AM

CTM,

That's pretty much exactly the code I have...before removing anything I wanted to just print out each element to verify I was getting the right information. That exact code that you have there is what throws the errors I put in the original post. That's why I'm so confused about this. It seems like that should work. But it's not. :-(

CTM · 04-13-2012, 10:15 AM

That's bizarre. Could you post your full source code?