# mkmcconn meaning here:
while (<DATA>) { # not "for"... no need to suck all into memory
    (my ($base, $ext) = /(\w+)\.(tiff?)\b/)
    if ($base) {
      # we have a good $base
    }
  }

# merlyn style here
while (<DATA>) { # not "for"... no need to suck all into memory
    if (my ($base, $ext) = /(\w+)\.(tiff?)\b/) {
      # we have a good $base or $ext
    }
  }