G'day george59,

Welcome to the Monastery.

I added an extra line to your input file. This tests that non-sequential ranges and numbers with more than one digit work correctly.

$ cat pm_11137734_input.txt
[0..1]
[2..4]
[5..8]
[10..13]
[download]

Here's the code I used:

#!/usr/bin/env perl

use strict;
use warnings;
use autodie;

my $infile = 'pm_11137734_input.txt';
my @values;
my $re = qr{^\[(\d+)\.\.(\d+)\]$};

{
    open my $fh, '<', $infile;
    /$re/ && push @values, $1 .. $2 while <$fh>;
}

# For demo purposes only:
use Data::Dump;
dd \@values;
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Output:

[0 .. 8, 10 .. 13]
[download]

You have some strange code related to I/O and no error checking. See how I've used open and autodie.