Confused about accessing hashes

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

Was rather proud of myself. Wrote a script that takes a badly formated xml file and coverts it into something that XML::Simple can handle. But, now that XML::Simple successfully reads in the XML file and puts into a hash. I can't figure out how to access the hash. This part always confuses me. I'd appreciate not only help, but perhaps a good document written at kindergarten level that explains this stuff. After running, Dumper shows the hash was loaded like so:

$VAR1 = {
          'ETPT' => {
                      'SERVER' => [
                                    {
                                      'RESPONSE' => '07:14:59,60,1236,
+31789,61,61,61,61,61,61,61,61,61,61,61,61,61,61,61,61,61,61,61
,61,61,61,61,61,61,61,61,61,61,186,61,119,61,61,119,119,61,92,61,92,14
+754,1397,1475,1625,365,1085,1660,1249,1883,928,672,366002,1821
,3591,3880,4505,4580,2877,1104,3165,4650,2420,1842,2548,2069,1382,3947
+,3913,4478,3096,2356,2857,3877,3398,3663,4134,1850,3661,5713,2
896,2173,4057,3161,1446,1497,3518,6443,4410,5154,11025,11907,8277,7890
+,5209,7109,5408,6133,5204,7057,6601,4907,7465,6403,6655,111717
,5640,6052,6000. . . .
                                      'CMD' => 'cq/quoteserver/qsclien
+ts/client-X.X.X.13.1057|showgraphwbu@',
                                      'CLIENT' => 'X.X.X.13.1057',
                                      'IP' => 'X.X.X.41'
                                    },
                                    {
                                      'RESPONSE' => '07:14:59,60,618,3
+2,32,922,32,32,31,32,31,32,32,31,32,32,31,32,31,32,32,31,32,31
,32,32,31,32,32,31,32,31,32,32,31,32,47,4047,32,31,32,32,1203,32,31,32
+,32,62,2063,31,32,469,31,32,32,31,32,31,32,32,31,32,31,32,32,3
1,32,32,31,63,1000,47,32,31,32,31,32,32,31,32,32,47,32,47,1906,32,31. 
+. .
etc etc etc
[download]

I want to be able to pull out all of the RESPONSE's for each IP. (there are multiple RESPONSE's per IP). Help me please...

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Re: Confused about accessing hashes by ambs (Pilgrim) on Apr 19, 2005 at 14:14 UTC
First, your $VAR1 is a reference to a hash with only one key, so `$VAR1->{ETPT}` [download] is needed. This one is another reference to another hash with only the key 'SERVER', so `$VAR1->{ETPT}{SERVER}` [download] Now, this is a reference to an array. You want to get all responses... `$VAR1->{ETPT}{SERVER}[0]{RESPONSE} # First element of the array $VAR1->{ETPT}{SERVER}[1]{RESPONSE} # Second element of the array` [download] Probably you want to go for each element of the array like this: `for (@{$VAR1->{ETPT}{SERVER}}) { # here $_->{RESPONSE} is each response of the array }` [download] Hope this helps. Alberto Simões	[reply] [d/l] [select]
Re^2: Confused about accessing hashes by ear (Acolyte) on Apr 19, 2005 at 14:23 UTC
Eureka! That was perfect and I actually get it now. Thanks MUCH. `$data = $xml->XMLin ("good.xml"); . . . for (@{$data->{ETPT}{SERVER}}) { print "$_->{IP}\n\t$_->{RESPONSE}\n"; }` [download]	[reply] [d/l]
Re: Confused about accessing hashes by RazorbladeBidet (Friar) on Apr 19, 2005 at 14:18 UTC
Might want to try perlreftut because those are actually hash references :) But here's a quick synopsis that (hopefully) helps (note that this is not complete): `Prepending: $ - a single item (scalar) @ - multiple items (array) % - hash Accessors: -> - dereference [] - array subscript {} - hash key` [download] If you work to combine those, then you should be able to access anything wrt hashes/arrays/keys. e.g. - `$var1->{$var2}->[$var3]` would return one element (the prepended $) from var1 which is a reference (->) to a hash ( {}'s ) with a key $var2 whose value is a reference (->) to an array ([]'s) with an index $var3 I hope that is more helpful than confusing :) The perldocs are much more complete. This is a rudimentary example, not intended to be 100% complete (fileglobs, lists, etc.) so please don't jump all over it (this addressed to the monastery at large :) ) -------------- "But what of all those sweet words you spoke in private?" "Oh that's just what we call pillow talk, baby, that's all."	[reply] [d/l] [select]
Re: Confused about accessing hashes by blazar (Canon) on Apr 19, 2005 at 14:19 UTC
I want to be able to pull out all of the RESPONSE's for each IP. (there are multiple RESPONSE's per IP). Help me please... Then just use... ehm... another hash!! Precisely a "HoA" with the IPs as keys and arrayrefs contaning the various responses as values.	[reply]