perl how to grab spesific string in paragraph style - perl

Question

I'm new on perl and still learning by doing some case. I've some case on parsing a log with perl.
There is a data log :
Physical interface: ge-1/0/2, Unit: 101, Vlan-id: 101, Address: 10.187.132.3/27
Index: 353, SNMP ifIndex: 577, VRRP-Traps: enabled
Interface state: up, Group: 1, State: backup, VRRP Mode: Active
Priority: 190, Advertisement interval: 1, Authentication type: none
Advertisement threshold: 3, Delay threshold: 100, Computed send rate: 0
Preempt: yes, Accept-data mode: yes, VIP count: 1, VIP: 10.187.132.1
Dead timer: 2.715s, Master priority: 200, Master router: 10.187.132.2
Virtual router uptime: 5w5d 12:54
Tracking: disabled
Physical interface: ge-1/0/2, Unit: 102, Vlan-id: 102, Address: 10.187.132.35/27
Index: 354, SNMP ifIndex: 580, VRRP-Traps: enabled
Interface state: up, Group: 2, State: master, VRRP Mode: Active
Priority: 200, Advertisement interval: 1, Authentication type: none
Advertisement threshold: 3, Delay threshold: 100, Computed send rate: 0
Preempt: yes, Accept-data mode: yes, VIP count: 1, VIP: 10.187.132.33
Advertisement Timer: 0.816s, Master router: 10.187.132.35
Virtual router uptime: 5w5d 12:54, Master router uptime: 5w5d 12:54
Virtual Mac: 00:00:5e:00:01:02
Tracking: disabled
Physical interface: ge-1/0/2, Unit: 103, Vlan-id: 103, Address: 10.187.132.67/27
Index: 355, SNMP ifIndex: 581, VRRP-Traps: enabled
Interface state: up, Group: 3, State: backup, VRRP Mode: Active
Priority: 190, Advertisement interval: 1, Authentication type: none
Advertisement threshold: 3, Delay threshold: 100, Computed send rate: 0
Preempt: yes, Accept-data mode: yes, VIP count: 1, VIP: 10.187.132.65
Dead timer: 2.624s, Master priority: 200, Master router: 10.187.132.66
Virtual router uptime: 5w5d 12:54
Tracking: disabled
I curious how we can retrieve some value and store it to array. I've tried grep it but I'm confuse how to take a spesific value.
Expected Value on Array of Hashes:
$VAR1 = {
'interface' => 'ge-1/0/2.101',
'address' => '10.187.132.3/27',
'State' => 'backup'
'Master-router' => '10.187.132.2'
};
$VAR2 = {
'interface' => 'ge-1/0/2.102',
'address' => '10.187.132.35/27',
'State' => 'master'
'Master-router' => '10.187.132.35'
};
$VAR3 = {
'interface' => 'ge-1/0/2.103',
'address' => '10.187.132.67/27',
'State' => 'backup'
'Master-router' => '10.187.132.66'
};

Answer 1

You could use regex to split each paragraph up. Something like this might work:
/((\w|\s|-)+):\s([^,]+)/m
The matching groups would then look something like:
Match 1
1. Physical interface
2. e
3. ge-1/0/2
Match 2
1. Unit
2. t
3. 101
Match 3
1. Vlan-id
2. d
3. 101
As you can see 1. corresponds to a key whereas 3. is the corresponding value. You can store the set of pairs any way you like.
For this to work each attribute in the log would need to be comma-seperated, which the example you have listed isn't. Assuming the example you have listed is correct, you would have to adjust the regex a little to make it work. You can test it online at rubular until it works. If it is comma seperated you might just want to split each paragraph by "," and then split each result on ":".
EDIT:
It seems to me like each line is comma seperated so the methods mentioned above might work perfectly well if you use them on a single line at a time.

Answer 2

To parse the data:
Obtain a section from the file by reading lines into a section while the lines start with whitespace.
Split the sections at the item separators which are either commas or linebreaks
Split each item at the first colon into a key and value
Case-fold the key and store the pair into a hash
A sketch of an implementation:
my #hashes;
while (<>) {
push #hashes, {} if /\A\S/;
for my $item (split /,/) {
my ($k, $v) = split /:/, $item, 2;
$hashes[-1]{fc $k} = $v;
}
}
Then you can extract those pieces of information from the hash which you are interested in.

Answer 3

Since each record is a paragraph, you can have Perl read the file in those chunks by local $/ = ''; (paragraph mode). Then, use a regex to capture each value that you want within that paragraph, pair that value with a hash key, and then push a reference to that hash onto an array to form an array of hashes (AoH):
use strict;
use warnings;
use Data::Dumper;
my #arr;
local $/ = '';
while (<DATA>) {
my %hash;
( $hash{'interface'} ) = /interface:\s+([^,]+)/;
( $hash{'address'} ) = /Address:\s+(\S+)/;
( $hash{'State'} ) = /State:\s+([^,]+)/;
( $hash{'Master-router'} ) = /Master router:\s+(\S+)/;
push #arr, \%hash;
}
print Dumper \#arr;
__DATA__
Physical interface: ge-1/0/2, Unit: 101, Vlan-id: 101, Address: 10.187.132.3/27
Index: 353, SNMP ifIndex: 577, VRRP-Traps: enabled
Interface state: up, Group: 1, State: backup, VRRP Mode: Active
Priority: 190, Advertisement interval: 1, Authentication type: none
Advertisement threshold: 3, Delay threshold: 100, Computed send rate: 0
Preempt: yes, Accept-data mode: yes, VIP count: 1, VIP: 10.187.132.1
Dead timer: 2.715s, Master priority: 200, Master router: 10.187.132.2
Virtual router uptime: 5w5d 12:54
Tracking: disabled
Physical interface: ge-1/0/2, Unit: 102, Vlan-id: 102, Address: 10.187.132.35/27
Index: 354, SNMP ifIndex: 580, VRRP-Traps: enabled
Interface state: up, Group: 2, State: master, VRRP Mode: Active
Priority: 200, Advertisement interval: 1, Authentication type: none
Advertisement threshold: 3, Delay threshold: 100, Computed send rate: 0
Preempt: yes, Accept-data mode: yes, VIP count: 1, VIP: 10.187.132.33
Advertisement Timer: 0.816s, Master router: 10.187.132.35
Virtual router uptime: 5w5d 12:54, Master router uptime: 5w5d 12:54
Virtual Mac: 00:00:5e:00:01:02
Tracking: disabled
Physical interface: ge-1/0/2, Unit: 103, Vlan-id: 103, Address: 10.187.132.67/27
Index: 355, SNMP ifIndex: 581, VRRP-Traps: enabled
Interface state: up, Group: 3, State: backup, VRRP Mode: Active
Priority: 190, Advertisement interval: 1, Authentication type: none
Advertisement threshold: 3, Delay threshold: 100, Computed send rate: 0
Preempt: yes, Accept-data mode: yes, VIP count: 1, VIP: 10.187.132.65
Dead timer: 2.624s, Master priority: 200, Master router: 10.187.132.66
Virtual router uptime: 5w5d 12:54
Tracking: disabled
Output:
$VAR1 = [
{
'Master-router' => '10.187.132.2',
'interface' => 'ge-1/0/2',
'address' => '10.187.132.3/27',
'State' => 'backup'
},
{
'Master-router' => '10.187.132.35',
'interface' => 'ge-1/0/2',
'address' => '10.187.132.35/27',
'State' => 'master'
},
{
'Master-router' => '10.187.132.66',
'interface' => 'ge-1/0/2',
'address' => '10.187.132.67/27',
'State' => 'backup'
}
];
Hope this helps!