$ perl -e 'use Digest::MD5; print Digest::MD5->new->md5_hex("foobarbaz")
,$/'
e05e07ceb87ddb19ccba8a51a57ac120

$ perl -e 'use Digest::MD5 qw(md5_hex); print md5_hex("foobarbaz"),$/'
6df23dc03f9b54cc38a0fc1483df6e21

$ echo -n foobarbaz | md5sum 
6df23dc03f9b54cc38a0fc1483df6e21 *-

$ mysql -e "select md5('foobarbaz')"
+----------------------------------+
| md5('foobarbaz')                 |
+----------------------------------+
| 6df23dc03f9b54cc38a0fc1483df6e21 |
+----------------------------------+

##</code><code>##

    use Digest::MD5;
    
    $md5 = Digest::MD5->new;
    $md5->add('foo', 'bar');
    $md5->add('baz');
    $digest = $md5->hexdigest;

##</code><code>##

sub create_checksum {

    my $self = shift;
    my $data = shift;

    my $foo = $$data;

    my $ctx = Digest::MD5->new;
    $ctx->add($foo);
    my $cs = $ctx->hexdigest();
    return $cs;
}

##</code><code>##

$ perl -e 'use Digest::MD5; my $x= Digest::MD5->new; $x->add("foobarbaz"); 
print $x->hexdigest,$/'
6df23dc03f9b54cc38a0fc1483df6e21