How to Pass array and hash from one script to another script?

I'm not sure if this is the best method, but you could use Data::Dumper and read the data from stdin.

test.pl

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

my %data = ( 
    key => 'value',
    arr => [ 0..5 ],
);

my $fh = FileHandle->new('| ./sample.pl') or
    die "Could not open pipe to './sample.pl': $!\n";
print $fh Data::Dumper->Dump([\%data], [qw(data)]);
$fh->close();

sample.pl

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

my $str = do { local $/; <STDIN> };
my $data;
eval $str;
if ($@) {
    die "Error in eval: $@\n";
}
$data->{key} = 'new value';
print Data::Dumper->Dump([$data], [qw(data)]);

output

$ ./test.pl 
$data = {
          'key' => 'new value',
          'arr' => [
                     0,
                     1,
                     2,
                     3,
                     4,
                     5
                   ]
        };

You can pass them as command-line arguments with their type as one of the cmd line values

And then check that cmd-line value containing type, which will be in @ARGV, in other script as below:

mainscript.pl

use strict;
use warnings;

# Variable
my $ele = 10;
system("perl sample.pl $ele varval");

# Array
my @arr = (1,2,3);
system("perl sample.pl @arr arrval");

# Hash
my %h = (
    'a' => 1,
    'b' => 2
);
my @a = %h;
system("perl sample.pl @a hashval");

Sample.pl

use Data::Dumper;
print("\nIn sample\n");

if($ARGV[-1] eq 'varval')
{
    print("\nIts var\n");
    delete($ARGV[-1]);
    print($ARGV[0]);
}
elsif ($ARGV[-1] eq 'arrval')
{
    print("\nIts array\n");
    delete($ARGV[-1]);
    @temparr = @ARGV;
    print(@temparr);
}
elsif ($ARGV[-1] eq 'hashval')
{
    print("\nIts hash\n");
    delete($ARGV[-1]);
    my %h1 = @ARGV;
    print(Dumper(\%h1));
}

Output:

D:\perlp>perl mainscript.pl

In sample

Its var 10

In sample

Its array 123

In sample

Its hash $VAR1 = { 'a' => '1', 'b' => '2' };

D:\perlp>

Why do you want to pass them via STDIN? I think its easier to write a short file before you start the system call. And read that file with the other script. You could pass the filename via STDIN, when you want to create a dynamic filename (when you have multiple executions or so).

Even when its a complex Object you want to pass. You could use that for Serialization. Its a CORE-Module.