open(FILE, "data.txt") or die "$!";
while(<FILE>){
  chomp;
  my @data = split(/,/,$_);
  print "test:\t$_\n" foreach (@data);
}
close FILE;
[download]

or

my @lines;
open(FILE, "data.txt") or die "$!";
while(<FILE>){
  chomp;
  my @data = split(/,/,$_);
  push @lines,\@data;
}
close FILE; 
foreach(@lines){
  print "test:\t$_\n" foreach (@$_);
}
[download]

depending on whether you want to store all of the lines in the file in an array for later processing....