Tokenize_a_string

#!/usr/local/bin/perl
#u# http://rosettacode.org/wiki/Tokenize_a_string
#c# 2018-08-10 <RC
#p# OK

use strict;
use warnings;
use feature 'say';
my $result;

$result .= join('.', split /,/, 'Hello,How,Are,You,Today') . "\n";

#CLI one-liner form:

# echo "Hello,How,Are,You,Today" | perl -aplF/,/ -e '$" = "."; $_ = "@F";'
# which is a compact way of telling Perl to do

BEGIN { $/ = "\n"; $\ = "\n"; }
#LINE: while (defined($_ = <ARGV>)) {
LINE: while (defined($_ = <DATA>)) {
    chomp $_;
    our(@F) = split(/,/, $_, 0);
    $" = '.';
    $_ = "@F";
}
continue {
    die "-p destination: $!\n" unless $result .= $_;
}

say $result; 

my $ref = <<'EOD';
Hello.How.Are.You.Today
Hello.How.Are.You.Today
EOD

use Test::More;
chop $ref;
is ($result, $ref);
done_testing;

__END__
Hello,How,Are,You,Today