Emacs Lisp: Run Current File

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This page shows a emacs lisp command that execute the current programing language file.

Problem Description

I want to be able to press a button, and have the current file executed or compiled. The file may be a Perl, Python, Ruby, PHP, Bash.

This way is even better than using a interactive command line (aka REPL), because you can write and edit normally with full emacs power. And you can run it by just pressing a key, such as F8.


Here's the solution:

(defun xah-run-current-file ()
  "Execute the current file.
For example, if the current buffer is the file xx.py, then it'll call 「python xx.py」 in a shell.
The file can be php, perl, python, ruby, javascript, bash, ocaml, vb, elisp.
File suffix is used to determine what program to run.

If the file is modified, ask if you want to save first.

URL `http://ergoemacs.org/emacs/elisp_run_current_file.html'
version 2014-10-28"
  (let* (
          ;; (‹extension› . ‹shell program name›)
            ("php" . "php")
            ("pl" . "perl")
            ("py" . "python")
            ("py3" . ,(if (string-equal system-type "windows-nt") "c:/Python32/python.exe" "python3"))
            ("rb" . "ruby")
            ("js" . "node") ; node.js
            ("sh" . "bash")
            ("clj" . "java -cp /home/xah/apps/clojure-1.6.0/clojure-1.6.0.jar clojure.main")
            ("ml" . "ocaml")
            ("vbs" . "cscript")
            ;; ("pov" . "/usr/local/bin/povray +R2 +A0.1 +J1.2 +Am2 +Q9 +H480 +W640")
         (ξfName (buffer-file-name))
         (ξfSuffix (file-name-extension ξfName))
         (ξprogName (cdr (assoc ξfSuffix ξsuffixMap)))
         (ξcmdStr (concat ξprogName " \""   ξfName "\"")))

    (when (buffer-modified-p)
      (when (y-or-n-p "Buffer modified. Do you want to save first?")

    (if (string-equal ξfSuffix "el") ; special case for emacs lisp
        (load ξfName)
      (if ξprogName
            (message "Running…")
            (shell-command ξcmdStr "*xah-run-current-file output*" ))
        (message "No recognized program file suffix for this file.")))))

The code is very easy to understand.

(info "(elisp) Association Lists")

(info "(elisp) Buffer File Name")

(info "(elisp) File Name Components")

Now, we can define a keyboard shortcut for this:

(global-set-key (kbd "<f8>") 'xah-run-current-file)

So now, doesn't matter we are writing in Perl, Python, elisp, …, we can just press a button and have the file executed or compiled.

Determine Language by Major Mode

If you don't have file extension, you might use the current major mode to determine what language it is.

The major mode's name is stored in the variable major-mode.

You also need to redefine your associative list to store major mode names corresponding to program paths.

(thanks to Matic Bojan for suggesting major mode for determining language.)

emacs ♥

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