Choosing Emacs settings based on operating system

snippet.el

;; Taken from https://karl-voit.at/2017/02/11/my-system-is-foobar/
;; Check if system is Darwin/macOS
(defun my-system-type-is-darwin ()
  "Return true if system is darwin-based (Mac OS X)"
  (string-equal system-type "darwin")
  )

;; Check if system is Microsoft Windows
(defun my-system-type-is-windows ()
  "Return true if system is Windows-based (at least up to Win7)"
  (string-equal system-type "windows-nt")
  )

;; Check if system is GNU/Linux
(defun my-system-type-is-gnu ()
  "Return true if system is GNU/Linux-based"
  (string-equal system-type "gnu/linux")
  )

(when (my-system-type-is-darwin)
  ;; EXAMPLE: (global-set-key (kbd "C-z") 'shell)
  ;; https://www.gnu.org/software/emacs/manual/html_node/emacs/Init-Rebinding.html#Init-Rebinding
  (global-set-key (kbd "s-/") 'comment-or-uncomment-region-or-line)
  )

(when (my-system-type-is-windows)
  (add-to-list 'exec-path "c:/sqlite/")
  (add-to-list 'exec-path "c:/Python/Python39")
  (add-to-list 'exec-path "c:/Windows/System32")
  (add-to-list 'exec-path "c:/MinGW/bin")
  (add-to-list 'exec-path "C:/MinGW/mingw32/bin")
  (add-to-list 'exec-path "C:/MinGW/msys/1.0/bin")
  (add-to-list 'exec-path "C:/tools/Git/usr/bin")
  (setenv "PATH" (mapconcat #'identity exec-path path-separator))
  )