+
+Within PROGRAM, %i denotes the input file, and %o denotes the
+output file.
+
+Otherwise, the rule is a compression rule, and compression is done with gzip.
+ARGS are command switches passed to PROGRAM.")
+
+(defvar dired-compress-files-alist
+ '(("\\.tar\\.gz\\'" . "tar -c %i | gzip -c9 > %o")
+ ("\\.tar\\.bz2\\'" . "tar -c %i | bzip2 -c9 > %o")
+ ("\\.tar\\.xz\\'" . "tar -c %i | xz -c9 > %o")
+ ("\\.zip\\'" . "zip %o -r --filesync %i"))
+ "Control the compression shell command for `dired-do-compress-to'.
+
+Each element is (REGEXP . CMD), where REGEXP is the name of the
+archive to which you want to compress, and CMD the the
+corresponding command.
+
+Within CMD, %i denotes the input file(s), and %o denotes the
+output file. %i path(s) are relative, while %o is absolute.")
+
+;;;###autoload
+(defun dired-do-compress-to ()
+ "Compress selected files and directories to an archive.
+You are prompted for the archive name.
+The archiving command is chosen based on the archive name extension and
+`dired-compress-files-alist'."
+ (interactive)
+ (let* ((in-files (dired-get-marked-files))
+ (out-file (read-file-name "Compress to: "))
+ (rule (cl-find-if
+ (lambda (x)
+ (string-match (car x) out-file))
+ dired-compress-files-alist)))
+ (cond ((not rule)
+ (error
+ "No compression rule found for %s, see `dired-compress-files-alist'"
+ out-file))
+ ((and (file-exists-p out-file)
+ (not (y-or-n-p
+ (format "%s exists, overwrite?"
+ (abbreviate-file-name out-file)))))
+ (message "Compression aborted"))
+ (t
+ (when (zerop
+ (dired-shell-command
+ (replace-regexp-in-string
+ "%o" out-file
+ (replace-regexp-in-string
+ "%i" (mapconcat #'file-name-nondirectory in-files " ")
+ (cdr rule)))))
+ (message "Compressed %d file(s) to %s"
+ (length in-files)
+ (file-name-nondirectory out-file)))))))