REBOL [Title: "REBOL Renamer"]
my_path: copy system/options/path
files_data: []
feedback_data: []
do-update-files-data: func []                                       					(1)
[
  change-dir my_path
  if exists? %../ [append files_data %../]
  append files_data sort read my_path
]
update-text-list: func [current_list [object!]]                    		 (2)
[
  current_list/sld/data: 0
  current_list/sn: 0
  current_list/sld/redrag current_list/lc / max 1 length? head current_list/lines
  show current_list
]
do-change-folder: func [selected [file!]]                           			(3)
[
  test_selection: to-file rejoin [my_path selected]
  if dir? test_selection
  [
    my_path: copy test_selection
    lab_path/text: clean-path my_path
    show lab_path
    clear files_data
    do-update-files-data
    update-text-list list_files
  ]
]
do-rename: func []                                                  						(4)
[
  messages: copy []
  foreach file read my_path
  [
    if not dir? file
    [
      if not none? find file fld_search/text
      [
        new-file: to-file replace to-string file fld_search/text fld_replace/text
        either exists? new-file
        [
          append messages rejoin ["FILENAME " new-file " ALREADY IN USE"]
        ]
        [
          append messages rejoin ["Renamed " file " to " new-file]
          rename file new-file
        ]
      ]
    ]
  ]
  return messages
]
do-go-action: func []                                               							(5)
[
  clear feedback_data
  insert feedback_data sort do-rename
  update-text-list list_feedback
  clear files_data
  do-update-files-data
  update-text-list list_files
]
do-update-files-data                                                							(6)
view layout [
  across
  label "Current Folder:"
  lab_path: label to-string my_path 300x50 top                      			(7)
  return
  list_files: text-list data files_data [do-change-folder value]  	(8)
  list_feedback: text-list data feedback_data
  return
  label "Search pattern:"
  fld_search: field
  return
  label "Replace pattern:"
  fld_replace: field
  return
  btn_go: button "Go" [do-go-action]                              				(9)
  btn_quit: button "Quit" [quit]
]