shell: Measure command durations.

.emacs.d/lisp/init-shell.el

@@ -32,10 +32,56 @@ prefix arg shell buffer doesn't exists, create it and switch to it."
 
 (advice-add 'helm-ff-switch-to-eshell :override 'ambrevar/helm-ff-switch-to-shell)
 
-(defun ambrevar/shell-ignore-history ()
+(defun ambrevar/shell-setup ()
   (set (make-variable-buffer-local 'comint-input-history-ignore)
-       (regexp-opt '("^#" "^ " "^cd "))))
+       (regexp-opt '("^#" "^ " "^cd ")))
+  (setq comint-prompt-regexp "^[^#$%>]*
+[#$%>] *"))
 
-(add-hook 'shell-mode-hook 'ambrevar/shell-ignore-history)
+(add-hook 'shell-mode-hook 'ambrevar/shell-setup)
+
+(defun ambrevar/shell-prompt ()
+  (buffer-substring-no-properties
+   (save-excursion
+     (re-search-backward comint-prompt-regexp))
+   (save-excursion
+     (comint-bol))))
+
+(defun ambrevar/shell-propertize-prompt ()        ; Inspired by `shx--propertize-prompt'.
+  "Add a mouseover timestamp to the last prompt."
+  (let ((inhibit-read-only t)
+        (inhibit-field-text-motion t))
+    (add-text-properties
+     (save-excursion
+       (re-search-backward comint-prompt-regexp)
+       (point))
+     (process-mark (get-buffer-process (current-buffer)))
+     `(help-echo ,(format-time-string "%F %T")))))
+
+(defun ambrevar/shell-send-input ()
+  "Send or parse the input currently written at the prompt.
+In normal circumstances this input is additionally filtered by
+`shx-filter-input' via `comint-mode'."
+  (interactive)
+  (ambrevar/shell-propertize-prompt)
+  (comint-send-input))
+(define-key shell-mode-map (kbd "<return>") 'ambrevar/shell-send-input)
+
+(defun ambrevar/shell-command-duration ()
+  "Return duration of command at point in a `shell' buffer."
+  (interactive)
+  (let ((begin (save-excursion
+                 (comint-previous-prompt 1)
+                 (re-search-backward comint-prompt-regexp)
+                 (parse-time-string (get-text-property (point) 'help-echo))))
+        (end (save-excursion
+               (comint-next-prompt 1)
+               (re-search-backward comint-prompt-regexp)
+               (parse-time-string (ambrevar/shell-prompt)))))
+    (message "Command took %fs seconds."
+             (- (float-time (apply 'encode-time end))
+                (float-time (apply 'encode-time begin))))))
+
+;; TODO: Narrow to output.
 
 (provide 'init-shell)