for my $file (@test_files) {
  # use $file here
  while (<TEST_FILE>) {
    # use $_ here
  }
}

##</code><code>##

for (1..3) {
  print "_ before = $_\n";
  for ('a'..'c') {
    print "_ inner loop = $_\n";
  }
  print "_ after = $_\n"; # prints same as before inner loop
}