;;; find-lisp.el --- emulation of find in Emacs Lisp -*- lexical-binding: t -*-
;; Author: Peter Breton
;; Created: Fri Mar 26 1999
;; Keywords: unix
;; Copyright (C) 1999-2022 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;
;; This is a very generalized form of find; it basically implements a
;; recursive directory descent. The conditions which bound the search
;; are expressed as predicates, and I have not addressed the question
;; of how to wrap up the common chores that find does in a simpler
;; format than writing code for all the various predicates.
;;
;; Some random thoughts are to express simple queries directly with
;; user-level functions, and perhaps use some kind of forms interface
;; for medium-level queries. Really complicated queries can be
;; expressed in Lisp.
;;
;;; Todo
;;
;; It would be nice if we could sort the results without running the find
;; again. Maybe that could work by storing the original file attributes?
;;; Code:
(require 'dired)
(defvar dired-buffers)
(defvar dired-subdir-alist)
;; Internal variables
(defvar find-lisp-regexp nil
"Internal variable.")
(defconst find-lisp-line-indent " "
"Indentation for Dired file lines.")
(defvar find-lisp-file-predicate nil
"Predicate for choosing to include files.")
(defvar find-lisp-directory-predicate nil
"Predicate for choosing to descend into directories.")
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Debugging Code
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defvar find-lisp-debug-buffer "*Find Lisp Debug*"
"Buffer for debugging information.")
(defvar find-lisp-debug nil
"Whether debugging is enabled.")
(defun find-lisp-debug-message (message)
"Print a debug message MESSAGE in `find-lisp-debug-buffer'."
(set-buffer (get-buffer-create find-lisp-debug-buffer))
(goto-char (point-max))
(insert message "\n"))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Directory and File predicates
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun find-lisp-default-directory-predicate (dir parent)
"True if DIR is not a dot file, and not a symlink.
PARENT is the parent directory of DIR."
(and find-lisp-debug
(find-lisp-debug-message
(format "Processing directory %s in %s" dir parent)))
;; Skip current and parent directories
(not (or (string= dir ".")
(string= dir "..")
;; Skip directories which are symlinks
;; Easy way to circumvent recursive loops
(file-symlink-p (expand-file-name dir parent)))))
(defun find-lisp-default-file-predicate (file dir)
"True if FILE matches `find-lisp-regexp'.
DIR is the directory containing FILE."
(and find-lisp-debug
(find-lisp-debug-message
(format "Processing file %s in %s" file dir)))
(and (not (file-directory-p (expand-file-name file dir)))
(string-match find-lisp-regexp file)))
(defun find-lisp-file-predicate-is-directory (file dir)
"True if FILE is a directory.
Argument DIR is the directory containing FILE."
(and find-lisp-debug
(find-lisp-debug-message
(format "Processing file %s in %s" file dir)))
(and (file-directory-p (expand-file-name file dir))
(not (or (string= file ".")
(string= file "..")))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Find functions
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun find-lisp-find-files (directory regexp)
"Find files under DIRECTORY, recursively, that match REGEXP."
(let ((file-predicate 'find-lisp-default-file-predicate)
(directory-predicate 'find-lisp-default-directory-predicate)
(find-lisp-regexp regexp))
(find-lisp-find-files-internal
directory
file-predicate
directory-predicate)))
;; Workhorse function
(defun find-lisp-find-files-internal (directory file-predicate
directory-predicate)
"Find files under DIRECTORY which satisfy FILE-PREDICATE.
FILE-PREDICATE is a function which takes two arguments: the file and its
directory.
DIRECTORY-PREDICATE is used to decide whether to descend into directories.
It is a function which takes two arguments, the directory and its parent."
(setq directory (file-name-as-directory directory))
(let (results sub-results)
(dolist (file (directory-files directory nil nil t))
(let ((fullname (expand-file-name file directory)))
(when (file-readable-p (expand-file-name file directory))
;; If a directory, check it we should descend into it
(and (file-directory-p fullname)
(funcall directory-predicate file directory)
(progn
(setq sub-results
(find-lisp-find-files-internal
fullname
file-predicate
directory-predicate))
(if results
(nconc results sub-results)
(setq results sub-results))))
;; For all files and directories, call the file predicate
(and (funcall file-predicate file directory)
(if results
(nconc results (list fullname))
(setq results (list fullname)))))))
results))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Find-dired all in Lisp
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;###autoload
(defun find-lisp-find-dired (dir regexp)
"Find the files within DIR whose names match REGEXP.
A Dired buffer with the results will be opened."
(interactive "DFind files in directory: \nsMatching regexp: ")
(let ((find-lisp-regexp regexp))
(find-lisp-find-dired-internal
dir
'find-lisp-default-file-predicate
'find-lisp-default-directory-predicate
"*Find Lisp Dired*")))
(defun find-lisp-find-dired-other-window (dir regexp)
"Same as `find-lisp-find-dired', but use another window."
(interactive "DFind files in directory: \nsMatching regexp: ")
(let ((find-lisp-regexp regexp))
(find-lisp-find-dired-internal
dir
'find-lisp-default-file-predicate
'find-lisp-default-directory-predicate
"*Find Lisp Dired*"
'OTHER-WINDOW)))
;; Just the subdirectories
;;;###autoload
(defun find-lisp-find-dired-subdirectories (dir)
"Find all subdirectories of DIR."
(interactive "DFind dired subdirectories of directory: ")
(find-lisp-find-dired-internal
dir
'find-lisp-file-predicate-is-directory
'find-lisp-default-directory-predicate
"*Find Lisp Dired Subdirectories*"))
;;;###autoload
(defun find-lisp-find-dired-subdirs-other-window (dir)
"Same as `find-lisp-find-dired-subdirectories', but use another window."
(interactive "DDired descendent dirs of directory: ")
(find-lisp-find-dired-internal dir
'find-lisp-file-predicate-is-directory
'find-lisp-default-directory-predicate
"*Find Lisp Dired Subdirectories*"
'OTHER-WINDOW))
;; Most of this is lifted from find-dired.el
;;
(defun find-lisp-find-dired-internal (dir file-predicate
directory-predicate buffer-name
&optional other-window)
"Run find (Lisp version) and go into Dired mode on a buffer of the output."
(let ((dired-buffers dired-buffers)
(regexp find-lisp-regexp))
;; Expand DIR ("" means `default-directory'), ensuring a trailing slash.
(setq dir (file-name-as-directory (expand-file-name dir)))
;; Check that it's really a directory.
(or (file-directory-p dir)
(error "find-dired needs a directory: %s" dir))
(unless (and (buffer-name) (string= buffer-name (buffer-name)))
(let ((buf (get-buffer-create buffer-name)))
(if other-window (pop-to-buffer buf) (switch-to-buffer buf))))
(widen)
(kill-all-local-variables)
(setq buffer-read-only nil)
(erase-buffer)
(setq default-directory dir)
(dired-mode dir)
(use-local-map (append (make-sparse-keymap) (current-local-map)))
(setq-local find-lisp-file-predicate file-predicate)
(setq-local find-lisp-directory-predicate directory-predicate)
(setq-local find-lisp-regexp regexp)
(setq-local revert-buffer-function
(lambda (_ignore1 _ignore2)
(find-lisp-insert-directory
default-directory
find-lisp-file-predicate
find-lisp-directory-predicate
'ignore)))
;; Set subdir-alist so that Tree Dired will work:
(if (fboundp 'dired-simple-subdir-alist)
;; will work even with nested dired format (dired-nstd.el,v 1.15
;; and later)
(dired-simple-subdir-alist)
;; else we have an ancient tree dired (or classic dired, where
;; this does no harm)
(setq dired-subdir-alist
(list (cons default-directory (point-min-marker)))))
(find-lisp-insert-directory
dir file-predicate directory-predicate 'ignore)
(goto-char (point-min))
(dired-goto-next-file)))
(defun find-lisp-insert-directory (dir
file-predicate
directory-predicate
_sort-function)
"Insert the results of `find-lisp-find-files' in the current buffer."
(let ((buffer-read-only nil)
(files (find-lisp-find-files-internal
dir
file-predicate
directory-predicate))
(len (length dir)))
(erase-buffer)
;; Subdir headlerline must come first because the first marker in
;; subdir-alist points there.
(insert find-lisp-line-indent dir ":\n")
;; Make second line a ``find'' line in analogy to the ``total'' or
;; ``wildcard'' line.
;;
;; No analog for find-lisp?
(insert find-lisp-line-indent "\n")
;; Run the find function
(mapc
(lambda (file)
(find-lisp-find-dired-insert-file
(substring file len)
(current-buffer)))
(sort files 'string-lessp))
;; FIXME: Sort function is ignored for now
;; (funcall sort-function files))
(goto-char (point-min))
(dired-goto-next-file)))
;;;###autoload
(defun find-lisp-find-dired-filter (regexp)
"Change the filter on a `find-lisp-find-dired' buffer to REGEXP."
(interactive "sSet filter to regexp: ")
(setq find-lisp-regexp regexp)
(revert-buffer))
(defun find-lisp-find-dired-insert-file (file buffer)
"Insert line for FILE in BUFFER.
FILE is a file or a directory name.
This function heeds `dired-actual-switches'."
(set-buffer buffer)
(insert find-lisp-line-indent
(find-lisp-format
(propertize file 'dired-filename t)
(file-attributes file 'string)
(or (and dired-actual-switches
(split-string-and-unquote dired-actual-switches))
(list ""))
nil)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Lifted from ls-lisp. We don't want to require it, because that
;; would alter the insert-directory function.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun find-lisp-format (file-name file-attr switches now)
"Format one line of long `ls' output for file or directory FILE-NAME.
FILE-ATTR and FILE-SIZE give the file's attributes and size.
SWITCHES and TIME-INDEX give the full switch list and time data."
(let ((file-type (file-attribute-type file-attr)))
(concat (and (memq ?i switches) ; inode number
(format "%6d " (file-attribute-inode-number file-attr)))
(and (memq ?s switches) ; size in K
(format "%4d " (1+ (/ (file-attribute-size file-attr) 1024))))
(file-attribute-modes file-attr)
(format " %3d %-8s %-8s %8d "
(file-attribute-link-number file-attr)
(if (numberp (file-attribute-user-id file-attr))
(int-to-string (file-attribute-user-id file-attr))
(file-attribute-user-id file-attr))
(if (eq system-type 'ms-dos)
"root" ; everything is root on MSDOS.
(if (numberp (file-attribute-group-id file-attr))
(int-to-string (file-attribute-group-id file-attr))
(file-attribute-group-id file-attr)))
(file-attribute-size file-attr))
(find-lisp-format-time file-attr switches now)
" "
file-name
(and (eq t file-type) (memq ?F switches)
"/") ; Add `/' for dir if `F' switch
(and (stringp file-type)
(concat " -> " file-type)) ; Add " -> " for symbolic link
"\n")))
(defun find-lisp-time-index (switches)
"Return index into file-attributes according to ls SWITCHES."
(cond
((memq ?c switches) 6) ; last mode change
((memq ?u switches) 4) ; last access
;; default is last modtime
(t 5)))
(defun find-lisp-format-time (file-attr switches now)
"Format time string for file.
This is done with attributes FILE-ATTR according to SWITCHES (a
list of ls option letters of which c and u are recognized). Use
the same method as \"ls\" to decide whether to show time-of-day or
year, depending on distance between file date and NOW."
(let* ((time (nth (find-lisp-time-index switches) file-attr))
(diff (time-convert (time-subtract time now) 'integer))
(past-cutoff -15778476) ; 1/2 of a Gregorian year
(future-cutoff (* 60 60))) ; 1 hour
(format-time-string
(if (<= past-cutoff diff future-cutoff)
"%b %e %H:%M"
"%b %e %Y")
time)))
(provide 'find-lisp)
;;; find-lisp.el ends here