#!/usr/bin/perl
use strict;
use warnings;

die("File does not exist.\n") unless -e $ARGV[0];

open(QUINE, "+<", shift);
my @quine = <QUINE>;

push @quine,
  'my @data = <DATA>;'."\n",
  'print @data, @data'."\n",
  "__END__\n";
push @quine, @quine;

seek(QUINE, 0, 0);
print QUINE @quine;
close(QUINE);
my @data = <DATA>;
print @data, @data
__END__
#!/usr/bin/perl
use strict;
use warnings;

die("File does not exist.\n") unless -e $ARGV[0];
open(QUINE, "+<", shift);
my @quine = <QUINE>;

push @quine, 
  'my @data = <DATA>;'."\n",
  'print @data, @data'."\n",
  "__END__\n";
push @quine, @quine;

seek(QUINE, 0, 0);
print QUINE @quine;
close(QUINE);
my @data = <DATA>;
print @data, @data
__END__