Add command to kill the current date

Comes up often enough, e.g. to add a stamp to a filename; probably was
the original motivation for my/kill-shell.

Gave a honest attempt at using a transient for this, but got bogged
down second-guessing whether I should define my arguments as
shorthands inside my transient-define-prefix form, or as dedicated
transient-define-argument forms; gave up while trying to figure out
whether the shorthand form could use transient-read-date.

1 files changed, 22 insertions, 1 deletions

diff --git a/.emacs b/.emacs
index e6d10bd..b3866da 100644
--- a/.emacs
+++ b/.emacs
@@ -186,6 +186,26 @@
 ;;   * executable: (info "(manual) Node"), "man 7 manual"
 ;;   * <https://somewhe.re/manual.html#node>
 
+(defun my/read (prompt default)
+  (read-string (format-prompt prompt default) nil nil default))
+
+(defun my/run (program &rest args)
+  (let ((handler (lambda (status)
+                   (unless (eq status 0)
+                     (user-error
+                      "%s returned %d:\n%s"
+                      program status (buffer-string))))))
+    (apply 'process-lines-handling-status program handler args)))
+
+(defun my/kill-date (date format)
+  (interactive
+   (if current-prefix-arg
+       (list (my/read "Date spec?" "today")
+             (my/read "Format?" "%F"))
+     (list "today" "%F")))
+  (my/kill
+   (car (my/run "date" (concat "-d" date) (concat "+" format)))))
+
 (defun my/kill-filename ()
   (interactive)
   (my/kill (or (buffer-file-name) default-directory)))
@@ -276,7 +296,8 @@
 
 (my/define-prefix-command my/kill-map
   "Keymap for adding things to the kill ring."
-  '(("f" my/kill-filename)
+  '(("d" my/kill-date)
+    ("f" my/kill-filename)
     ("|" my/kill-pipe-region)
     ("!" my/kill-shell)))