Question

Say I am editing a Perl file or buffer in Emacs in the default Perl mode (the one that comes with Emacs 23.1.1).

Is there a way to directly send the full file (or buffer) to the Perl interpreter and see the result (on a separate buffer)?

Answer 1

There are third party modes for running inferior perl processes and interacting with them (e.g. inf-perl.el), but nothing that comes included with emacs 23.1.1.

However, an easy way to run your buffer with perl is with shell-command-on-region. For example, this function will run perl on your buffer and display the output in a buffer called *Perl Output*:

(defun perl-on-buffer ()
  (interactive)
  (shell-command-on-region (point-min) (point-max) "perl" "*Perl Output*")
  (display-buffer "*Perl Output*"))

Run it in a perl buffer with M-x perl-on-buffer or bind it to a key like so:

(eval-after-load 'perl-mode
  '(define-key perl-mode-map (kbd "C-c C-c") 'perl-on-buffer))

Another option is to use compile/recompile with perl <filename> as the compile command. This works on the file contents rather than the buffer contents, and has the added advantage of navigating errors with C-x ` (next-error).