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

# use Benchmark qw(:all) ; # WindowsOS
use Benchmark::Forking qw( timethese cmpthese ); # LinuxOS

my @preserved = @ARGV;

=Hash Of Arrays
my %HoA;
while (<>) {
    chomp;
    push @{ $HoA{$ARGV} }, $_;
} continue {
    close ARGV if eof;
}

print Dumper \%HoA;

__END__

$ perl test.pl in.txt out.txt
$VAR1 = {
          'in.txt' => [
                        'Sample of text line 1',
                        '',
                        'Sample of text line 2'
                      ],
          'out.txt' => [
                         'Sample of text line 1 second file',
                         '',
                         'Sample of text line 2 second file'
                       ]
        };
=cut

sub while_loop {
    my @output;
    @ARGV = @preserved; # restore original @ARGV
    while (<>) {
	chomp;
	push @output, $_;
    } continue {
	close ARGV if eof;
    }
    return;
}

sub file_to_array {
    @ARGV = @preserved; # restore original @ARGV
    chomp (my @data = <>);
    close ARGV if eof;
    return;
}

my $results = timethese(10000000, { Array => \&file_to_array,
				    While => \&while_loop }, 'none');
cmpthese( $results );

__END__

$ perl test.pl in.txt in2.txt
          Rate Array While
Array 115513/s    --   -4%
While 120846/s    5%    --