message: [interactive] let user specify files.  If none, then scan for new/changed files.
diff: @@ -37,6 +37,7 @@ formatter="$script_dir"/verible-verilog-format
  # version control system
  # auto-detect by default
  rcs=auto
  +files=()
  function usage() {
  cat <<EOF
  @@ -44,9 +45,10 @@ $0:
  Interactively prompts user to accept/reject formatter tool changes,
  based only on touched lines of code in a revision-controlled workspace.
  -Usage: $script_name [script_options]
  +Usage: $script_name [script_options] [FILES...]
  Run this from a version-controlled directory.
  +If FILES is empty, scan for all Verilog files under the current directory.
  script options:
  --help, -h : print help and exit
  @@ -81,8 +83,8 @@ do
  --rcs ) prev_opt=rcs ;;
  --rcs=* ) rcs="$optarg" ;;
  --* | -* ) msg "Unknown option: $opt" ; exit 1 ;;
  - # This script expects no positional arguments.
  - *) { msg "Unexpected positional argument: $opt" ; usage ; exit 1 ;} ;;
  + # Positional arguments [optional] are files.
  + *) files+=( "$opt" ) ;;
  esac
  shift
  done
  @@ -124,8 +126,12 @@ case "$rcs" in
  *) { msg "Unsupported version control system: $rcs" ; exit 1;} ;;
  esac
  +# If files is unspecified, scan for all locally modified files.
  +if [[ "${#files[@]}" == 0 ]]
  +then
  # File extensions are currently hardcoded to Verilog files.
  files=($("$touched_files" | grep -e '\.sv$' -e '\.v$' -e '\.svh$' -e '\.vh$' ))
  +fi
  # Note about --per-file-transform-flags:
  # The file name is stripped away to yield only line numbers, which is why
  