#!

use Data::Dumper;
use strict;
use warnings;

{ # open one input - works with TieInput
    warn "opening in1.txt:\n";
    open my $in1,"<","in1.txt" or die $!;
    my $s=<$in1>;
    warn Data::Dumper->Dump([\$s],[qw(*s)]).' ';
    my @a=<$in1>;
    warn Data::Dumper->Dump([\@a],[qw(*a)]).' ';
    close $in1;
     };

{ # open two inputs - fails with TieInput
    warn "opening in1.txt and in2.txt:\n";
    open my $in1,"<","in1.txt" or die $!;
    open my $in2,"<","in2.txt" or die $!;
    my $s=<$in1>;
    warn Data::Dumper->Dump([\$s],[qw(*s)]).' ';
    $s=<$in2>;
    warn Data::Dumper->Dump([\$s],[qw(*s)]).' ';
    my @a=<$in1>;
    warn Data::Dumper->Dump([\@a],[qw(*a)]).' ';
    @a=<$in2>;
    warn Data::Dumper->Dump([\@a],[qw(*a)]).' ';
    close $in1;
    close $in2;
     };

exit;