Looks like you didn't set a value for your CSV data file variable, "$datafile". You need to specify a file for that variable. Then, it should work like a charm.

use Text::CSV::Simple;
my $parser = Text::CSV::Simple->new;
my $datafile = "SamnsCSVFile.csv";
my @data = $parser->read_file($datafile);
print @$_ foreach @data;

Enjoy,
D-Day