From 8fd98de30046174a6f0c2960a5c7b32252809912 Mon Sep 17 00:00:00 2001
From: Case Duckworth
Date: Fri, 28 May 2021 20:47:58 -0500
Subject: Add eshell last argument

https://old.reddit.com/r/emacs/comments/nlefvx/weekly_tips_and_tricks/gzpng5o/
---
 init.el | 40 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/init.el b/init.el
index 4c3bcdb..8d18dd9 100644
--- a/init.el
+++ b/init.el
@@ -314,7 +314,45 @@
               (define-key eshell-mode-map (kbd "C-d")
                 #'eshell-quit-or-delete-char)
               (when (boundp 'simple-modeline--mode-line)
-                (setq mode-line-format '(:eval simple-modeline--mode-line))))))
+                (setq mode-line-format '(:eval simple-modeline--mode-line)))))
+
+  (with-eval-after-load 'eshell
+    ;; Record arguments
+    (defvar my-eshell-arg-history nil)
+    (defvar my-eshell-arg-history-index nil)
+    (add-to-list 'savehist-additional-variables 'my-eshell-arg-history)
+
+    (defun my-eshell-record-args (&rest _)
+      "Record unique arguments onto the front of `my-eshell-arg-history'."
+      (setq my-eshell-arg-history
+            (cl-loop with history = my-eshell-arg-history
+                     for arg in (reverse eshell-last-arguments)
+                     do (setq history (cons arg (remove arg history)))
+                     finally return history)))
+
+    (defun my-eshell-insert-prev-arg ()
+      "Insert an argument from `my-eshell-arg-history' at point."
+      (interactive)
+      (if (eq last-command 'my-eshell-insert-prev-arg)
+          (progn
+            (let ((pos (point)))
+              (eshell-backward-argument 1)
+              (delete-region (point) pos))
+            (if-let ((text (nth my-eshell-arg-history-index
+                                my-eshell-arg-history)))
+                (progn
+                  (insert text)
+                  (cl-incf my-eshell-arg-history-index))
+              (insert (cl-first my-eshell-arg-history))
+              (setq my-eshell-arg-history-index 1)))
+        (insert (cl-first my-eshell-arg-history))
+        (setq my-eshell-arg-history-index 1)))
+
+    (add-hook 'eshell-mode-hook
+              (lambda ()
+                (add-hook 'eshell-post-command-hook
+                          #'my-eshell-record-args nil t)
+                (local-set-key (kbd "M-.") #'my-eshell-insert-prev-arg)))))
 
 (setup eww
   (:option eww-search-prefix "https://duckduckgo.com/html?q="
-- 
cgit 1.4.1-21-gabe81