Recreating hash

The data you show has an error in it. There should be a ' following "(UTC)".

Assuming the code shown in the OP with the syntax error corrected:

my %hash = %$VAR1;

print "At $hash{alerts}[0]{timestamp}: $hash{alerts}[0]{text}\n";
[download]

Prints:

At 1347395226: 95.019 (value) &gt; 95 (max limit) between Tue 20:19 - 
+Tue 20:20 (UTC)
[download]

If that's not the help you wanted you'll need to be more explicit.

True laziness is hard work

[reply]
[d/l]
[select]

Whops on the syntax error.. Thanks for your quick reply GF. I got the second part of my answer and now looking for the first part. Since this is the output of the hash, how would you recreate this hash from scratch in a perl program (with the same elements and what not)? I'm having trouble with the elements and the double references of => into =>.

[reply]

I don't understand "how to create it in the perl code" given that what you show is Perl code. What are you actually having trouble with? Maybe you should give us some context so we understand where you are coming from?

True laziness is hard work

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References quick reference

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use strict;
use warnings;

my %hash =(
          'alerts' => [
                        {
                          'min_failure_count' => '3',
                          'status_history' => {
                                                'status' => [
                                                              1,
                                                              1,
                                                              1,
                                                              0,
                                                              0,
                                                              0,
                                                              1,
                                                              1,
                                                              0,
                                                              0
                                                            ],
                                                'ts' => [
                                                          1347395526,
                                                          1347395226,
                                                          1347394926,
                                                          1347394626,
                                                          1347394326,
                                                          1347394026,
                                                          1347393726,
                                                          1347393426,
                                                          1347393126,
                                                          1347392826
                                                        ]
                                              },
                          'status_code' => 1,
                          'original_status_code' => 'BAD',
                          'dimensions' => {
                                            'cluster' => '1',
                                            'filesystem' => '/',
                                            'hostgroup' => 'hiho',
                                            'service' => 'system.fs-us
+ed_pct',
                                            'host' => 'limonata'
                                          },
                          'best_group' => 'NO GROUP',
                          'timestamp' => 1347395226,
                          'text' => '95.019 (value) &gt; 95 (max limit
+) between Tue 20:19 - Tue 20:2+0 (UTC)',
                          'check_type' => 'system.fs-used_pct',
                          'window_size' => '3'
                        }
                      ],
          'bad_alerts' => 1,
          'recovery_alerts' => 0
 );
[download]

I hope life isn't a big joke, because I don't get it.
-SNL

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[d/l]

NetWallah showed how to recreate the hash, and GrandFather demonstrated "...how to extract data from the hash...:"

print "At $hash{alerts}[0]{timestamp}: $hash{alerts}[0]{text}\n";
                   ^    ^      ^
                   |    |      |
                   |    |      + - hash key
                   |    + - zeroth element of array
                   + - hash key

# {} means hash; [] means array
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If you add and run the following line below the initialized hash:

say "$_ => $hash{$_}" for keys %hash;
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it'll generate the following output:

alerts => ARRAY(0x2562880)
recovery_alerts => 0
bad_alerts => 1
[download]

The key recovery_alerts is associated with the value 0, and the key bad_alerts is associated with the value 1. However, the key alerts is associated with an array reference, thus the 'alerts' => [... notation above in the hash initialization.

So, what's in that array--or at least the zeroth element? Try the following (the [0] notation dereferences the array reference, specifying element 0):

print $hash{alerts}[0];
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Output:

HASH(0x379350)
[download]

It's a hash reference, and the hash begins here in the hash initialization:

'alerts' => [
                {
                ^
                |
                + - beginning of hash
[download]

We can print the keys of this hash with the following:

say "$_ => $hash{alerts}[0]{$_}" for keys %{$hash{alerts}[0]};
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Output:

min_failure_count => 3
status_history => HASH(0x4ec628)
status_code => 1
original_status_code => BAD
dimensions => HASH(0x4f9440)
best_group => NO GROUP
timestamp => 1347395226
text => 95.019 (value) &gt; 95 (max limit) between Tue 20:19 - Tue 20:
+20 (UTC)
window_size => 3
check_type => system.fs-used_pct
[download]

Remember that $hash{alerts}[0] contains a hash reference. We enclose this with %{} to dereference it to get its keys in the line above. Each key (the values taken by $_) from the hash is 'plugged' into $hash{alerts}[0]{$_}, to get the key's associated value.

Does the structure $hash{alerts}[0]{$_} look familiar? Look back to the line GrandFather created:

print "At $hash{alerts}[0]{timestamp}: $hash{alerts}[0]{text}\n";
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^^^^^
[download]

From the structure you provided, he showed "...how to extract data from the hash..."

Hope this helps!

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[d/l]
[select]

Data::Dumper is used to create such dumps. For example,

use Data::Dumper;
print Dumper \%myhash;
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\

To get your structure back in the program, you can use do or eval. See Data::Dumper and eval for more info on restoring Dumper files.

Sorry if my advice was wrong.

[reply]
[d/l]
[select]

if ($hash{alerts}[0]{status_history}{status}  =~ /1,1,1,1,1,1/)
{
do cool stuff
}
[download]

[reply]
[d/l]


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