$ cat foo.pl
#!/usr/bin/perl

use strict;
use warnings;

my $file=shift;
open my $fh, $file or die $!;

print "The contents of `$file' are:\n", <$fh>;

__END__

$ ./foo.pl aaa 
The contents of `aaa' are:
asdfdaf
sfdfdd
sffgsdd

$ ./foo.pl '|echo "Gotcha!">foo.pl'
The contents of `|echo "Gotcha!">foo.pl' are:

$ cat foo.pl
Gotcha!