#!perl -w

=head1 USAGE

./combine.pl output_file input_1 input_2 [..., input_x]

Where output_file is the file to which all input files
(input_1, input_2, ..., input_x) should be combined to.

=cut

use strict;

my $out = shift @ARGV;

open( my $out_fh, '>', $out )
    or die("Could not open output file '$out': $!\n");

for my $file (@ARGV) {
    open( my $in_fh, '<', $file )
        or die("Error opening '$file': $!\n");
    print $out_fh $_ while (<$in_fh>);
    close($in_fh) or die("Error closing '$file': $!\n");

    print $out_fh "\n";    
}

close($out_fh) or die("Error closing '$out': $!\n");