Question

I’m using Fsharp mode in emacs.
The key of ^C x is mapped to Run ... command which is as follows.

(defun fsharp-run-executable-file ()
  (interactive)
  (let ((name (buffer-file-name)))
    (if (string-match "^\\(.*\\)\\.\\(fs\\|fsi\\)$" name)
        (shell-command (concat (match-string 1 name) ".exe")))))

The problem is that it tries to run bash something.exe, whereas I need to run the command of mono something.exe. I got error message of /bin/bash ...exe: cannot execute binary file.

How can I come up with a new elisp command to launch mono, and then get the result to show it to *compilation* buffer?

Answer 1

You can redefine fsharp-run-executable-file and use this one instead:

(defun fsharp-run-executable-file ()
  (interactive)
  (let ((name (buffer-file-name)))
    (if (string-match "^\\(.*\\)\\.\\(fs\\|fsi\\)$" name)
        (compile (concat "mono " (match-string 1 name) ".exe")))))

There are two changes: 1) concat mono before the command (as petebu wrote); 2) use the compile function so that the output is in the *compilation* buffer.

To test quickly, just evaluate the above function (add it in your Emacs init file for a permanent change). Note that you shouldn’t modify fsharp.el file, at I might update at some point (you don’t want to lost your changes).

Edit

One issue with the previous function is that it modifies the last compilation command. This might might annoying if you compile your code with compile or recompile commands. Here is a fix:

(defun fsharp-run-executable-file ()
  (interactive)
  (let ((name (buffer-file-name)))
    (if (string-match "^\\(.*\\)\\.\\(fs\\|fsi\\)$" name)
        (compilation-start (concat "mono " (match-string 1 name) ".exe")))))