From c1e9d58379ebb589dd09f513dd7850922797871c Mon Sep 17 00:00:00 2001
From: Tom Willemse <tom@ryuslash.org>
Date: Sat, 25 Jan 2014 21:53:11 +0100
Subject: [PATCH] Initial commit

---
 eshell-fringe-status.el | 115 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 eshell-fringe-status.el

diff --git a/eshell-fringe-status.el b/eshell-fringe-status.el
new file mode 100644
index 0000000..a3bd616
--- /dev/null
+++ b/eshell-fringe-status.el
@@ -0,0 +1,115 @@
+;;; eshell-fringe-status.el --- Show last status in fringe  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2014  Tom Willemse
+
+;; Author: Tom Willemse <tom@ryuslash.org>
+;; Keywords:
+;; Version: 0.1.0
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Show an indicator of the status of the last command run in eshell.
+;; To use, enable `eshell-fringe-status-mode' in `eshell-mode'.  The
+;; easiest way to do this is by adding a hook:
+
+;; : (add-hook 'eshell-mode-hook #'eshell-fringe-status-mode)
+
+;; This mode uses a rather hackish way to try and keep everything
+;; working in regard to `eshell-prompt-regexp', so if anything breaks
+;; please let me know.
+
+;;; Code:
+
+(require 'em-prompt)
+
+(defgroup eshell-fringe-status
+  nil
+  "Settings for command exit status shown in Emacs' fringe."
+  :group 'eshell
+  :prefix "eshell-fringe")
+
+(defface eshell-fringe-status-success
+  '((t (:foreground "#00ff00")))
+  "Face used to indicate success status."
+  :group 'eshell-fringe-status)
+
+(defface eshell-fringe-status-failure
+  '((t (:foreground "#ff0000")))
+  "Face used to indicate failed status."
+  :group 'eshell-fringe-status)
+
+(define-fringe-bitmap 'efs--arrow-bitmap
+  [#b10000
+   #b11000
+   #b11100
+   #b11110
+   #b11111
+   #b11110
+   #b11100
+   #b11000
+   #b10000] 9 5 'center)
+
+(defun efs--extend-prompt-regexp ()
+  "Add a space at the beginning of `eshell-prompt-regexp'.
+
+Since the fringe bitmap is added as a space with a special
+display value, any existing regexp in `eshell-prompt-regexp'
+which doesn't accept at least one space will break."
+  (let ((first (aref eshell-prompt-regexp 0)))
+    (when (eql first ?^)
+      (setq eshell-prompt-regexp
+            (format "%c %s" first (substring eshell-prompt-regexp 1))))))
+
+(defun efs--revert-prompt-regexp ()
+  "The counterpart for `efs--extend-prompt-regexp', remove a space.
+
+Since when the mode is started a space is added to the beginning
+of `eshell-prompt-regexp' it should also be removed when
+disabling the mode."
+  (let ((first (aref eshell-prompt-regexp 0)))
+    (when (and (eql first ?^)
+               (eql (aref eshell-prompt-regexp 1) ?\s))
+      (setq eshell-prompt-regexp
+            (format "%c%s" first (substring eshell-prompt-regexp 2))))))
+
+(defun eshell-fringe-status ()
+  "Display an indication of the last command's exit status.
+
+This indication is shown as a bitmap in the left fringe of the
+window."
+  (save-excursion
+    (beginning-of-line)
+    (insert
+     (propertize " " 'display
+                 `((left-fringe efs--arrow-bitmap
+                                ,(if (zerop eshell-last-command-status)
+                                     'eshell-fringe-status-success
+                                   'eshell-fringe-status-failure)))))))
+
+(define-minor-mode eshell-fringe-status-mode
+  "Show exit status of last command in fringe."
+  nil nil nil
+  (if eshell-fringe-status-mode
+      (progn
+        (efs--extend-prompt-regexp)
+        (add-hook 'eshell-after-prompt-hook
+                  #'eshell-fringe-status nil :local))
+    (efs--revert-prompt-regexp)
+    (remove-hook 'eshell-after-prompt-hook
+                 #'eshell-fringe-status :local)))
+
+(provide 'eshell-fringe-status)
+;;; eshell-fringe-status.el ends here