#!/usr/bin/perl
# test1.pl
use strict;
use warnings;

my $array = ( 1, 2, 3, 4);
open my $FH, '| ./test2.pl';
print $FH @{$array};
close $FH;

#!/usr/bin/perl
# test2.pl
use strict;
use warnings;

while (my $var = <>){
    print $var;
}

##</code><code>##

#!/usr/bin/perl
# test1.pl
use strict;
use warnings;

my $array = ( 1, 2, 3, 4);
my $program = 'test2.pl';
exec { $program } @{$array};

#!/usr/bin/perl
# test2.pl
use strict;
use warnings;

print "$_ " foreach @ARGV;

##</code><code>##

`exec` can be written:

exec { $program } @{$array};
exec $program, @{$array};
exec { './test2.pl' } @{$array};
exec './test2.pl', @{$array};
exec './test2.pl', 1, 2, 3, 4;