Passing Emacs variables to minibuffer shell commands

Question

I can run a shell command quickly by hitting M-!. One thing I\'d like to do is perform shell quick operations on the current file. An example would be checking th

Answer 1

Everyone seems to be rolling their own version, so here's mine -- it will substitue the current filename or marked dired-files or current dired file wherever a % is in the shell command. It follows the same conventions as M-! so I bind it to that.

(defun my-shell-command (command &optional output-buffer error-buffer)
  "Run a shell command with the current file (or marked dired files).
In the shell command, the file(s) will be substituted wherever a '%' is."
  (interactive (list (read-from-minibuffer "Shell command: "
                                           nil nil nil 'shell-command-history)
                     current-prefix-arg
                     shell-command-default-error-buffer))
  (cond ((buffer-file-name)
         (setq command (replace-regexp-in-string "%" (buffer-file-name) command nil t)))
        ((and (equal major-mode 'dired-mode) (save-excursion (dired-move-to-filename)))
         (setq command (replace-regexp-in-string "%" (mapconcat 'identity (dired-get-marked-files) " ") command nil t))))
  (shell-command command output-buffer error-buffer))