in reply to Generation of Array of hashes by reading a file

Doing a two step via flag is not needed 


#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;
################
my @AoH;
my $rec;
open my $fh, '<', 'interface.txt' or die;
while (<$fh>) {
    chomp;
    if (/^(\w+\d{1}):\s+flags=(.*?>)/) {
        $rec = {};
        push @AoH, $rec;
        $rec->{'interface'} = $1;
        $rec->{'flags'} = $2;
    } elsif (/ether\s+(.*$)/) {
        $rec->{'ether'} = $1;
    } elsif (/media:\s+(\w+)/) {
        $rec->{'media'} = $1;
    } elsif (/inet\s+(\w+\.\w+\.\w+\.\w+)/) {
        $rec->{'inet'} = $1;
    }  elsif (/status: (\w+)/) {
        $rec->{'status'} = $1;
    }
}

close($fh);
print Dumper \@AoH;

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Re^2: Generation of Array of hashes by reading a file
by NetWallah (Canon) on Jan 04, 2018 at 21:27 UTC
    Slightly shorter loop: 
    # After "open" ..
my %wanted = map {$_=>1} qw|media inet status ether|;
while (<$fh>) {
    chomp;
    if (/^(\w+\d{1}):\s+flags=(.*?>)/) {
        $rec = {};
        push @AoH, $rec;
        $rec->{'interface'} = $1;
        $rec->{'flags'} = $2;
        next;
    }
    if (/(\w+):?\s+(.*$)/ and $wanted{$1}) {
        $rec->{$1} = $2;
    } 
}

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                    We're living in a golden age. All you need is gold. -- D.W. Robertson.

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[d/l]
Re^2: Generation of Array of hashes by reading a file
by pr33 (Scribe) on Jan 04, 2018 at 21:58 UTC

    Thanks Huck and other Monks. All the solutions work. One of the doubt I had with this, Every time when the line matches the key related to interface, we are making the hash empty and then pushing that on to Array. I was assuming the Array will only contain a list of empty hashes, But not the case when I run the script with your solution. Can you please explain or help me understand the push statement after assigning empty hash to rec

[reply]
      $rec is not a hash, it's a hash reference. When you change the referenced hash, all references pointing to it see the new value.

      my $hash_ref = {};
push my @arr, $hash_ref;
$hash_ref->{key} = 'value';
print $arr[0]{key};  # value

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      ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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[reply]
[d/l]
[select]

        Thanks Choroba. That cleared my confusion around this.

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