I have a hash, much like the one below:

%cmdData = (
     'command_1' => {
          'subfields' => [],
          'description' => 'descriptive text',
          'safety' => 'SAFE'
                    },
     'command_2' => {
          'subfields' => [
               {
                  '_size' => 32,
                   'state_conversions' => [],
                   'subfield_name' => 'sub_1',
                   '_fsw_type' => 'UINT32',
               },
               {
                  '_size' => 32,
                   'state_conversions' => [],
                   'subfield_name' => 'sub_2',
                   '_fsw_type' => 'UINT32',
               },
                          ],
          'description' => 'descriptive text',
          'safety' => 'SAFE',
                    }
)
[download]

What I want to do is to loop through each command (key) in the hash, and do X if it has one or more subfields, and Y if it has 0 subfields. So I have a foreach loop in my code (below), with an if/else statement.

Problem is, I can't get the if/else conditions right. I have tried it as below, and I have tried if (not defined $cmdData->{$cmd}{subfields}). In both cases, it prints all the command names, followed by "defined".

#!/usr/bin/perl -w
use strict;
use warnings;
use Storable;

my %info;
my $cmdData = retrieve('file.pm')

foreach my $cmd ( sort { $cmdData->{$a}{pkt_target} cmp $cmdData->{$b}
+{pkt_target} || $a cmp $b } keys %{$cmdData}) {
    print "$cmd   ";

    if ($cmdData->{$cmd}{subfields} eq "") {
        print "undef\n";
    } else {
        print "defined\n";
    }
};
[download]

Yes, I can change the hash I'm working with - sort of. I have a preprocessing script that is compiling a whole mess of hashes of the same format into one big one in a file (so it's easier to iterate through later). I can change that script to output something nicer, but I still need to know how to tell if there are subfields or not (this is how they appear in the original hashes I'm pulling from) so I can fix them.

Thanks a million, Monks!

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.