Filtering text through a shell command in Emacs

Question

In vi[m] there is the ! command which lets me pipe text through a shell command -- like sort or indent -- and get the filtered text back into the buffer. Is there an equivalent in emacs?

Answer 1

You can select a region and type `C-u M-| command RET', and it replaces the region with the command output in the same buffer due to the interactive prefix argument of shell-command-on-region.

Answer 2

I wrote this a few years back, it might help you:

(defun generalized-shell-command (command arg)   "Unifies `shell-command' and `shell-command-on-region'. If no region is selected, run a shell command just like M-x shell-command (M-!).  If no region is selected and an argument is a passed, run a shell command and place its output after the mark as in C-u M-x `shell-command' (C-u M-!).  If a region is selected pass the text of that region to the shell and replace the text in that region with the output of the shell command as in C-u M-x `shell-command-on-region' (C-u M-|). If a region is selected AND an argument is passed (via C-u) send output to another buffer instead of replacing the text in region."   (interactive (list (read-from-minibuffer "Shell command: " nil nil nil 'shell-command-history)                      current-prefix-arg))   (let ((p (if mark-active (region-beginning) 0))         (m (if mark-active (region-end) 0)))     (if (= p m)         ;; No active region         (if (eq arg nil)             (shell-command command)           (shell-command command t))       ;; Active region       (if (eq arg nil)           (shell-command-on-region p m command t t)         (shell-command-on-region p m command))))) 

I've found this function to be very helpful. If you find it useful as well, I suggest binding it to some function key for convenience, personally I use F3:

(global-set-key [f3] 'generalized-shell-command)