While the documentation states that archive mode supports rar files, I seem to have no luck with it. Trying to view/open a rar file in dired, lead to this message:

File mode specification error: (file-error Searching for program No such file or directory lsar)

My emacs version is 25.2.1. I suspect the source of the error is here, in using unar instead of unrar:

(defun archive-rar-extract (archive name)
  ;; unrar-free seems to have no way to extract to stdout or even to a file.
  (if (file-name-absolute-p name)
      ;; The code below assumes the name is relative and may do undesirable
      ;; things otherwise.
      (error "Can't extract files with non-relative names")
    (archive-extract-by-file archive name `("unar" "-no-directory" "-o") "Successfully extracted")))

I don't have experience modifying compiled emacs lisp libraries. Would love to know what is causing this error.

  • 1
    Yep, that looks like a bug to me. I would report it to the Emacs team, and try fixing it yourself in the meantime. You can require the library (require 'arc-mode) and then use the same function name and everything, while just changing the program name. In my own setup, I actually substituted it with an absolute path to a registered version of unrar which required modifying some of the regexp functions since the output was slightly different. My recollection is that arc-mode was based on the assumption everyone would be using an unrar free version, which was not available to me.
    – lawlist
    Commented Sep 10, 2017 at 5:30

1 Answer 1


On Arch Linux, installing unarchiver from the AUR solved the problem. The programs unar and lsar are provided by the said package from the AUR.

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