#!/usr/bin/env perl

use strict;
use warnings;

my @filter;

my $line = <DATA>;
#open (my $ffile, '<','filterfile') or die "cannot open filterfile: $!
+";
#my $line = <$ffile>;
#while ($line = <$ffile>) {
while ($line = <DATA>) {
    chomp $line;
    my ($col,$rel,$val,$foa,$ord) = split /\s+/,$line;
    $filter[$ord] = [ $col,$rel,$val,$foa ];
}

for my $ord (1 .. 3) {
    print "$ord:\n",
          "\tcol: "   ,$filter[$ord]->[0],"\n",
          "\trsh: "   ,$filter[$ord]->[1],"\n",
          "\tvalue: " ,$filter[$ord]->[2],"\n",
          "\tf_o_a: " ,$filter[$ord]->[3],"\n\n";
}

__DATA__
column relationship value filter_or_append order
a      <=           0.3   filter           1
b      =            abc   append           3
c      <=           0.3   filter           2
[download]

Each element of @filter is a reference to an anonymous array which contains values: [...].

Produces:

1:
    col: a
    rsh: <=
    value: 0.3
    f_o_a: filter

2:
    col: c
    rsh: <=
    value: 0.3
    f_o_a: filter

3:
    col: b
    rsh: =
    value: abc
    f_o_a: append
[download]

Awesome!! Quick question. Did you mean to comment out the three lines under my $line = <DATA>. If so, why? Thanks again. Much appreciated.

In this example, I use __DATA__ section and read it with <DATA>. This way, all is included in one file.

But you will probably use an external file. To do that, just delete my $line = <DATA>; and while ($line = <DATA>) { (and __DATA__ section). Then uncomment the three lines.

Excelent choice of data structure if $ord is always a small interger and there are few (if any) gaps in the sequence.

True. It could be better to push $ord in an array to sort and write an hash using $ord as key...

Looking for sparse array perl, I find that: Implementing a Sparse Array

#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;

my @filter;

<>; # read one line from the file/stdin

while (<>) { # read other lines
 chomp; # remove "\n" from the end of the line
 push @filter,[(split /\t/,$_)]; # create an array of the line by spli
+tting it by <TAB>, make a reference of it and push the reference to t
+he @filter array
}

@filter = sort { $a->[4] <=> $b->[4] } @filter; # sort the array by 5t
+h element of embedded arrays

print Dumper \@filter;
[download]

This method is also great. I know that I can print any specific clump of data. Ex.  print Dumper \@filter[0] to get the first clump of data in the array. My question is, can I (and if I can, how can I) pull out the individual elements in the array. Ex.

 
$VAR1 = \[
            '1000_Genomes',
            '<=',
            '0.03',
            'filter ',
'           '1
          ];
[download]

is the output I get when I print  Dumper \@filter[0] . I need to be able to use each individual element (1000_Genomes, <=, 0.03, etc..) separately throughout my program. Should I store these values in variables or what? Thanks for your assistance!!!!

You can access elements by their nubmers. For example, print $filter[0]->[0],"\n" should print 1000_Genomes.

-> is necessary because @filter array contents are not real arrays, but references to arrays.

Sorry if my advice was wrong.