Hello zarath,

Something like that could work.

I am sure that another Monk will come up with a better solution but is a good working starting point.

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

open(my $fh1, ">>", "output1.txt")
    or die "Can't open > output1.txt: $!";

open(my $fh2, ">>", "output2.txt")
    or die "Can't open > output2.txt: $!";

my $count = 1;
while (<>) { # Read all files that provided through ARGV
    chomp;
    if ($count == 1 or $count == 2) {
    say $fh1 $_;
    }
    elsif ($count == 3 or $count == 4) {
    say $fh2 $_;
    }
    if ($count == 4) {
    $count = 1;
    }
    else {
    $count++;
    }
} continue {
    close ARGV if eof; # reset $. each file
}

close($fh1)
    or warn "Can't close output1.txt: $!";

close($fh2)
    or warn "Can't close output2.txt: $!";

__END__

$ cat output1.txt
Sample of text line 1
Sample of text line 2
Sample of text line 5
Sample of text line 6
$ cat output2.txt
Sample of text line 3
Sample of text line 4
[download]

The code is self explained, you provide the script $ perl test.pl in.txt and then the output files are defined inside. I open them in append mode so every line that we print is bellow the other.

Update: Minor code modification:

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

open(my $fh1, ">>", "output1.txt")
    or die "Can't open > output1.txt: $!";

open(my $fh2, ">>", "output2.txt")
    or die "Can't open > output2.txt: $!";

my $count = 1;
while (<>) { # Read all files that provided through ARGV
    chomp;
    if ($count == 1 or $count == 2) {
    say $fh1 $_;
    }
    elsif ($count == 3 or $count == 4) {
    say $fh2 $_;
    }
    if ($count == 4) { $count = 1; next; }
    $count++;
} continue {
    close ARGV if eof; # reset $. each file
}

close($fh1)
    or warn "Can't close output1.txt: $!";

close($fh2)
    or warn "Can't close output2.txt: $!";
[download]

Update2: Minor code improvement:

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

open(my $fh1, ">>", "output1.txt")
    or die "Can't open > output1.txt: $!";

open(my $fh2, ">>", "output2.txt")
    or die "Can't open > output2.txt: $!";

while (<>) { # Read all files that provided through ARGV
    chomp;
    if ($. == 1 or $. == 2) {
    say $fh1 $_;
    }
    elsif ($. == 3 or $. == 4) {
    say $fh2 $_;
    }
    $. = 0 if ($. == 4);
} continue {
    close ARGV if eof; # reset $. each file
}

close($fh1)
    or warn "Can't close output1.txt: $!";

close($fh2)
    or warn "Can't close output2.txt: $!";
[download]

Final Update:

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

open(my $fh1, ">>", "output1.txt")
    or die "Can't open > output1.txt: $!";

open(my $fh2, ">>", "output2.txt")
    or die "Can't open > output2.txt: $!";

while (<>) { # Read all files that provided through ARGV
    chomp;
    if ($. == 1 or $. == 2) {
    say $fh1 $_;
    next;
    }
    say $fh2 $_;
    $. = 0 if ($. == 4);
} continue {
    close ARGV if eof; # reset $. each file
}

close($fh1)
    or warn "Can't close output1.txt: $!";

close($fh2)
    or warn "Can't close output2.txt: $!";
[download]