Using Emacs 66 - an eshell switcher in elisp

I thought it was time to give eshell in Emacs another try. It has some pretty cool features but for whatever reason, I've never really been able to adopt Emacs as my go to shell.

Eshell out of the box is pretty cool but could use some enhancements. When launching at login it doesn't know about the path you set in your .bashrc or .zshrc in my case files. It just seemed to have problems with paths in general but that was fixed with the exce-path-from-shell package. The prompt also needed some fixing up along with some other tweaks.

I found aweshell which looked promising but it wasn't on melpa so I had to clone it separately. I also noticed that it basically tied together some packages I could download myself and added a shell switcher but didn't bind the keys.

I thought I'd dive into elisp -something I haven't done in a while to write my own.

Here's my current complete eshell config:

(use-package exec-path-from-shell
  :ensure t
  :config
  (exec-path-from-shell-initialize))


    (use-package fish-completion
    :ensure t
    :config
    (global-fish-completion-mode))
  ;; (use-package eshell-prompt-extras 
  ;; :ensure t
  ;; :config
  ;; (setq epe-show-python-info nil)
  ;; )

  (use-package eshell-git-prompt
  :ensure t
  :config
  (eshell-git-prompt-use-theme 'git-radar)
  )

And here's the code I ended up with for my shell switcher:

#+BEGIN_SRC emacs-lisp
  (require 'cl-lib)
  (defun select-or-create (arg)
    "Commentary ARG."
    (if (string= arg "New eshell")
        (eshell t)
      (switch-to-buffer arg)))
  (defun eshell-switcher (&optional arg)
    "Commentary ARG."
    (interactive)
    (let* (
           (buffers (cl-remove-if-not (lambda (n) (eq (buffer-local-value 'major-mode n) 'eshell-mode)) (buffer-list)) )
           (names (mapcar (lambda (n) (buffer-name n)) buffers))
           (num-buffers (length buffers) )
           (in-eshellp (eq major-mode 'eshell-mode)))
      (cond ((eq num-buffers 0) (eshell (or arg t)))
            ((not in-eshellp) (switch-to-buffer (car buffers)))
            (t (select-or-create (completing-read "Select Shell:" (cons "New eshell" names)))))))

I currently bound eshell-switcher to CTRL-z e.

The video goes through the whole process:

2020-02-08

emacs