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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-16 09:50:25 +00:00
emacs/lisp/find-lisp.el
Paul Eggert bc511a64f6 Prefer HTTPS to FTP and HTTP in documentation
Most of this change is to boilerplate commentary such as license URLs.
This change was prompted by ftp://ftp.gnu.org's going-away party,
planned for November.  Change these FTP URLs to https://ftp.gnu.org
instead.  Make similar changes for URLs to other organizations moving
away from FTP.  Also, change HTTP to HTTPS for URLs to gnu.org and
fsf.org when this works, as this will further help defend against
man-in-the-middle attacks (for this part I omitted the MS-DOS and
MS-Windows sources and the test tarballs to keep the workload down).
HTTPS is not fully working to lists.gnu.org so I left those URLs alone
for now.
2017-09-13 15:54:37 -07:00

362 lines
12 KiB
EmacsLisp

;;; find-lisp.el --- emulation of find in Emacs Lisp -*- lexical-binding: t -*-
;; Author: Peter Breton
;; Created: Fri Mar 26 1999
;; Keywords: unix
;; Copyright (C) 1999-2017 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 files in DIR, matching REGEXP."
(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*")))
;; Just the subdirectories
;;;###autoload
(defun find-lisp-find-dired-subdirectories (dir)
"Find all subdirectories of DIR."
(interactive "DFind subdirectories of directory: ")
(find-lisp-find-dired-internal
dir
'find-lisp-file-predicate-is-directory
'find-lisp-default-directory-predicate
"*Find Lisp Dired Subdirectories*"))
;; Most of this is lifted from find-dired.el
;;
(defun find-lisp-find-dired-internal (dir file-predicate
directory-predicate buffer-name)
"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), and make sure it has 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))
(or
(and (buffer-name)
(string= buffer-name (buffer-name)))
(switch-to-buffer (get-buffer-create buffer-name)))
(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)))
(make-local-variable 'find-lisp-file-predicate)
(setq find-lisp-file-predicate file-predicate)
(make-local-variable 'find-lisp-directory-predicate)
(setq find-lisp-directory-predicate directory-predicate)
(make-local-variable 'find-lisp-regexp)
(setq find-lisp-regexp regexp)
(make-local-variable 'revert-buffer-function)
(setq revert-buffer-function
(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)
(set (make-local-variable '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
(function
(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)
(set-buffer buffer)
(insert find-lisp-line-indent
(find-lisp-format file (file-attributes file 'string) (list "")
(current-time))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; 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 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 (nth 0 file-attr)))
(concat (if (memq ?i switches) ; inode number
(format "%6d " (nth 10 file-attr)))
;; nil is treated like "" in concat
(if (memq ?s switches) ; size in K
(format "%4d " (1+ (/ (nth 7 file-attr) 1024))))
(nth 8 file-attr) ; permission bits
(format " %3d %-8s %-8s %8d "
(nth 1 file-attr) ; no. of links
(if (numberp (nth 2 file-attr))
(int-to-string (nth 2 file-attr))
(nth 2 file-attr)) ; uid
(if (eq system-type 'ms-dos)
"root" ; everything is root on MSDOS.
(if (numberp (nth 3 file-attr))
(int-to-string (nth 3 file-attr))
(nth 3 file-attr))) ; gid
(nth 7 file-attr) ; size in bytes
)
(find-lisp-format-time file-attr switches now)
" "
file-name
(if (stringp file-type) ; is a symbolic link
(concat " -> " file-type)
"")
"\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))
(diff16 (- (car time) (car now)))
(diff (+ (ash diff16 16) (- (car (cdr time)) (car (cdr now)))))
(past-cutoff (- (* 6 30 24 60 60))) ; 6 30-day months
(future-cutoff (* 60 60))) ; 1 hour
(format-time-string
(if (and
(<= past-cutoff diff) (<= diff future-cutoff)
;; Sanity check in case `diff' computation overflowed.
(<= (1- (ash past-cutoff -16)) diff16)
(<= diff16 (1+ (ash future-cutoff -16))))
"%b %e %H:%M"
"%b %e %Y")
time)))
(provide 'find-lisp)
;;; find-lisp.el ends here