diff --git a/configuration.org b/configuration.org
index 093ecb1..bfef215 100644
--- a/configuration.org
+++ b/configuration.org
@@ -49,6 +49,266 @@ I set it up early so I can use it in ~use-package~ calls immediately.
                          user-emacs-directory))
 #+END_SRC
 
+* Custom commands and functions
+
+** Misc text manipulation functions
+
+*** Delete the current line
+
+#+BEGIN_SRC emacs-lisp
+(defun gpolonkai/delete-current-line ()
+  "Kill the whole line on which point is."
+  (interactive)
+
+  (beginning-of-line)
+  (kill-line 1))
+#+END_SRC
+
+*** Duplicate current line
+
+#+BEGIN_SRC emacs-lisp
+(defun gpolonkai/duplicate-line()
+  "Duplicate line at point."
+
+  (interactive)
+
+  (save-excursion
+    (move-beginning-of-line 1)
+    (kill-line)
+    (yank)
+    (open-line 1)
+    (forward-line 1)
+    (yank)))
+#+END_SRC
+
+*** Toggle case of character at point
+
+Based on [[http://ergoemacs.org/emacs/modernization_upcase-word.html][Xah’s toggle letter case defun version 2015-12-22]]
+
+#+BEGIN_SRC emacs-lisp
+(defun toggle-char-case (arg-move-point)
+  "Toggle the case of the char after point.
+
+If prefix argument ARG-MOVE-POINT is non-nil, move point after the char."
+  (interactive "P")
+  (let ((case-fold-search nil))
+    (cond
+     ((looking-at "[[:lower:]]") (upcase-region (point) (1+ (point))))
+     ((looking-at "[[:upper:]]") (downcase-region (point) (1+ (point)))))
+    (cond
+     (arg-move-point (right-char)))))
+#+END_SRC
+
+*** Open a new line below
+
+Copied from http://whattheemacsd.com/editing-defuns.el-01.html
+
+#+BEGIN_SRC emacs-lisp
+(defun open-line-below ()
+  "Open a new line below point."
+
+  (interactive)
+
+  (end-of-line)
+  (newline)
+  (indent-for-tab-command))
+#+END_SRC
+
+*** Open a new line above
+
+#+BEGIN_SRC emacs-lisp
+(defun open-line-above ()
+  "Open a new line above point."
+
+  (interactive)
+
+  (beginning-of-line)
+  (newline)
+  (forward-line -1)
+  (indent-for-tab-command))
+#+END_SRC
+
+*** TODO Kill or copy the whole line
+
+Got from Xah’s site (TODO is for adding a link here.)
+
+#+BEGIN_SRC emacs-lisp
+(defun æ-kill-or-copy-whole-line (kill)
+  "Kill or copy the whole line point is on.
+
+If KILL is non-nil, the line gets killed.  Otherwise, it gets just
+copied to the kill ring."
+  (interactive "P")
+
+  (if kill
+      (kill-whole-line)
+    (let ((beginning (progn (beginning-of-line) (point)))
+          (end (progn (end-of-line) (point))))
+      (copy-region-as-kill beginning end))))
+#+END_SRC
+
+** Navigation
+
+*** Move to different beginnings of the current line
+
+Inspired by Bozhidar Batsov's [[http://emacsredux.com/blog/2013/05/22/smarter-navigation-to-the-beginning-of-a-line/][solution]].
+
+#+BEGIN_SRC emacs-lisp
+(defun gpolonkai/move-to-beginning-of-line ()
+  "Move to different beginnings of the line.
+
+These are, in order:
+
+- beginning of the visual line if `visual-line-mode' is active,
+- the first non-whitespace (indentation),
+- the actual beginning of the line.
+
+This function will jump between the first character and the
+indentation if used multiple times."
+  (interactive)
+  (let ((last-pos (point)))
+    (when visual-line-mode
+      (beginning-of-visual-line))
+    (when (= (point) last-pos)
+      (back-to-indentation))
+    (when (= (point) last-pos)
+      (beginning-of-line))
+    (when (and (eq major-mode 'org-mode)
+               (= (point) last-pos))
+      (org-beginning-of-line))
+    (when (= (point) last-pos)
+      (back-to-indentation))))
+#+END_SRC
+
+*** Move to the different ends of the current line
+
+#+BEGIN_SRC emacs-lisp
+(defun gpolonkai/move-to-end-of-line ()
+  "Move to the end of the line.
+
+If `visual-line-mode' is active, jump to the end of the visual
+line first.  Then jump to the actual end of the line."
+  (interactive)
+  (let ((last-pos (point)))
+    (when visual-line-mode
+      (end-of-visual-line))
+    (when (= (point) last-pos)
+      (end-of-line))
+    (when (and (eq major-mode 'org-mode)
+               (= (point) last-pos))
+      (org-end-of-line))))
+#+END_SRC
+
+** File manipulation
+
+*** Rename the current file
+
+Copied from http://whattheemacsd.com/file-defuns.el-01.html
+
+#+BEGIN_SRC emacs-lisp
+(defun rename-current-buffer-file ()
+  "Renames current buffer and file it is visiting."
+  (interactive)
+
+  (let ((name (buffer-name))
+        (filename (buffer-file-name)))
+    (if (not (and filename (file-exists-p filename)))
+        (error "Buffer '%s' is not visiting a file!" name)
+      (let ((new-name (read-file-name "New name: " filename)))
+        (if (get-buffer new-name)
+            (error "A buffer named '%s' already exists!" new-name)
+          (rename-file filename new-name 1)
+          (rename-buffer new-name)
+          (set-visited-file-name new-name)
+          ; TODO: this is suspicious for me…
+          (set-buffer-modified-p nil)
+          (message "File '%s' successfully renamed to '%s'"
+                   name (file-name-nondirectory new-name)))))))
+#+END_SRC
+
+*** Delete the current file
+
+Copied from http://whattheemacsd.com/file-defuns.el-02.html
+
+#+BEGIN_SRC emacs-lisp
+(defun delete-current-buffer-file ()
+  "Remove file connected to current buffer and kill the buffer."
+  (interactive)
+
+  (let ((filename (buffer-file-name))
+        (name (buffer-name))
+        (buffer (current-buffer)))
+    (if (not (and filename (file-exists-p filename)))
+        (kill-buffer buffer)
+      (when (yes-or-no-p "Are you sure you want to remove this file? ")
+        (delete-file filename)
+        (kill-buffer buffer)
+        (message "File '%s' successfully removed" filename)))))
+#+END_SRC
+
+*** Allow reopening the previously closed file
+
+#+BEGIN_SRC emacs-lisp
+(defvar gpolonkai/last-killed-buffer-file-name
+  nil
+  "The last killed buffer.
+
+Used by `gpolonkai/kill-this-buffer' and `gpolonkai/undo-buffer-kill'.")
+
+(defun gpolonkai/kill-this-buffer ()
+  "Kill the current buffer, but save the buffer file name so it can be undone."
+  (interactive)
+  (setq gpolonkai/last-killed-buffer-file-name (buffer-file-name))
+  (kill-this-buffer))
+
+(defun gpolonkai/undo-buffer-kill ()
+  "Undo killing the last buffer.
+
+Esentially it visits the file again."
+  (interactive)
+  (if gpolonkai/last-killed-buffer-file-name
+      (progn
+        (find-file gpolonkai/last-killed-buffer-file-name)
+        (setq gpolonkai/last-killed-buffer-file-name nil))
+    (message "The buffer last killed didn’t visit a file.")))
+#+END_SRC
+** ~c-mode~ related
+
+*** Copy the prototype of the current function
+
+#+BEGIN_SRC emacs-lisp
+(defun gpolonkai/copy-func-prototype ()
+  "Copy the current function's prototype to the kill ring."
+
+  (interactive)
+
+  (save-excursion
+    (beginning-of-defun)
+    (let ((protocopy-begin (point)))
+      (forward-list)
+      (let ((protocopy-end (point)))
+        (kill-ring-save protocopy-begin protocopy-end)))))
+#+END_SRC
+
+** EShell related
+
+*** Delete a character, or close ~eshell~ if nothing to delet
+
+Copied from https://ryuslash.org/posts/C-d-to-close-eshell.html
+
+#+BEGIN_SRC emacs-lisp
+(defun eshell-C-d ()
+  "Either call `delete-char' interactively or quit."
+  (interactive)
+
+  (condition-case err
+      (call-interactively #'delete-char)
+    (error (if (and (eq (car err) 'end-of-buffer)
+                    (looking-back eshell-prompt-regexp nil))
+               (kill-buffer)
+             (signal (car err) (cdr err))))))
+#+END_SRC
+
 * UI preferences
 
 ** Tweak window chrome
diff --git a/init.el b/init.el
index 14ab945..89f13cb 100644
--- a/init.el
+++ b/init.el
@@ -30,7 +30,6 @@
 (load "round-number-to-decimals")
 (load "zim")
 (load "enclose-string")
-(load "buf-manipulation")
 (load "text-manip")
 (load "frame-manip")
 (load "file-manip")
@@ -1154,7 +1153,7 @@ INFO plist."
  ("C-M-r" . isearch-backward)
  ("C-~" . toggle-char-case)
  :map ctl-x-map
- ("C-y" . duplicate-line)
+ ("C-y" . gpolonkai/duplicate-line)
  ("_" . maximize-window)
  ("C-r" . rename-current-buffer-file)
  ("C-d" . delete-current-buffer-file)
diff --git a/lisp/buf-manipulation.el b/lisp/buf-manipulation.el
deleted file mode 100644
index e3ac46b..0000000
--- a/lisp/buf-manipulation.el
+++ /dev/null
@@ -1,203 +0,0 @@
-;;; buf-manipulation --- Summary
-;; Some custom functions for buffer content manipulation
-;;
-;;; Commentary:
-
-;;; Code:
-(defun delete-current-line ()
-  "Kill the whole line on which point is."
-  (interactive)
-
-  (beginning-of-line)
-  (kill-line 1))
-
-(defun copy-func-prototype ()
-  "Copy the current function's prototype to the kill ring."
-
-  (interactive)
-
-  (save-excursion
-    (beginning-of-defun)
-    (let ((protocopy-begin (point)))
-      (forward-list)
-      (let ((protocopy-end (point)))
-        (kill-ring-save protocopy-begin protocopy-end)))))
-
-(defun duplicate-line()
-  "Duplicate line at point."
-
-  (interactive)
-
-  (save-excursion
-    (move-beginning-of-line 1)
-    (kill-line)
-    (yank)
-    (open-line 1)
-    (forward-line 1)
-    (yank)))
-
-;; Based on Xah's toggle letter case defun version 2015-12-22
-;;
-;; URL: http://ergoemacs.org/emacs/modernization_upcase-word.html
-(defun toggle-char-case (arg-move-point)
-  "Toggle the case of the char after point.
-
-If prefix argument ARG-MOVE-POINT is non-nil, move point after the char."
-  (interactive "P")
-  (let ((case-fold-search nil))
-    (cond
-     ((looking-at "[[:lower:]]") (upcase-region (point) (1+ (point))))
-     ((looking-at "[[:upper:]]") (downcase-region (point) (1+ (point)))))
-    (cond
-     (arg-move-point (right-char)))))
-
-; Copied from http://whattheemacsd.com/editing-defuns.el-01.html
-(defun open-line-below ()
-  "Open a new line below point."
-
-  (interactive)
-
-  (end-of-line)
-  (newline)
-  (indent-for-tab-command))
-
-(defun open-line-above ()
-  "Open a new line above point."
-
-  (interactive)
-
-  (beginning-of-line)
-  (newline)
-  (forward-line -1)
-  (indent-for-tab-command))
-
-; Copied from http://whattheemacsd.com/file-defuns.el-01.html
-(defun rename-current-buffer-file ()
-  "Renames current buffer and file it is visiting."
-  (interactive)
-
-  (let ((name (buffer-name))
-        (filename (buffer-file-name)))
-    (if (not (and filename (file-exists-p filename)))
-        (error "Buffer '%s' is not visiting a file!" name)
-      (let ((new-name (read-file-name "New name: " filename)))
-        (if (get-buffer new-name)
-            (error "A buffer named '%s' already exists!" new-name)
-          (rename-file filename new-name 1)
-          (rename-buffer new-name)
-          (set-visited-file-name new-name)
-          ; TODO: this is suspicious for me…
-          (set-buffer-modified-p nil)
-          (message "File '%s' successfully renamed to '%s'"
-                   name (file-name-nondirectory new-name)))))))
-
-; Copied from http://whattheemacsd.com/file-defuns.el-02.html
-(defun delete-current-buffer-file ()
-  "Remove file connected to current buffer and kill the buffer."
-  (interactive)
-
-  (let ((filename (buffer-file-name))
-        (name (buffer-name))
-        (buffer (current-buffer)))
-    (if (not (and filename (file-exists-p filename)))
-        (kill-buffer buffer)
-      (when (yes-or-no-p "Are you sure you want to remove this file? ")
-        (delete-file filename)
-        (kill-buffer buffer)
-        (message "File '%s' successfully removed" filename)))))
-
-;; delete-char or close eshell
-;; Copied from https://ryuslash.org/posts/C-d-to-close-eshell.html
-(defun eshell-C-d ()
-  "Either call `delete-char' interactively or quit."
-  (interactive)
-
-  (condition-case err
-      (call-interactively #'delete-char)
-    (error (if (and (eq (car err) 'end-of-buffer)
-                    (looking-back eshell-prompt-regexp nil))
-               (kill-buffer)
-             (signal (car err) (cdr err))))))
-
-(defun æ-kill-or-copy-whole-line (kill)
-  "Kill or copy the whole line point is on.
-
-If KILL is non-nil, the line gets killed.  Otherwise, it gets just
-copied to the kill ring."
-  (interactive "P")
-
-  (if kill
-      (kill-whole-line)
-    (let ((beginning (progn (beginning-of-line) (point)))
-          (end (progn (end-of-line) (point))))
-      (copy-region-as-kill beginning end))))
-
-;; Inspired by Bozhidar Batsov's solution:
-;;
-;; http://emacsredux.com/blog/2013/05/22/smarter-navigation-to-the-beginning-of-a-line/
-(defun gpolonkai/move-to-beginning-of-line ()
-  "Move to different beginnings of the line.
-
-These are, in order:
-
-- beginning of the visual line if `visual-line-mode' is active,
-- the first non-whitespace (indentation),
-- the actual beginning of the line.
-
-This function will jump between the first character and the
-indentation if used multiple times."
-  (interactive)
-  (let ((last-pos (point)))
-    (when visual-line-mode
-      (beginning-of-visual-line))
-    (when (= (point) last-pos)
-      (back-to-indentation))
-    (when (= (point) last-pos)
-      (beginning-of-line))
-    (when (and (eq major-mode 'org-mode)
-               (= (point) last-pos))
-      (org-beginning-of-line))
-    (when (= (point) last-pos)
-      (back-to-indentation))))
-
-(defun gpolonkai/move-to-end-of-line ()
-  "Move to the end of the line.
-
-If `visual-line-mode' is active, jump to the end of the visual
-line first.  Then jump to the actual end of the line."
-  (interactive)
-  (let ((last-pos (point)))
-    (when visual-line-mode
-      (end-of-visual-line))
-    (when (= (point) last-pos)
-      (end-of-line))
-    (when (and (eq major-mode 'org-mode)
-               (= (point) last-pos))
-      (org-end-of-line))))
-
-(defvar gpolonkai/last-killed-buffer-file-name
-  nil
-  "The last killed buffer.
-
-Used by `gpolonkai/kill-this-buffer' and `gpolonkai/undo-buffer-kill'.")
-
-(defun gpolonkai/kill-this-buffer ()
-  "Kill the current buffer, but save the buffer file name so it can be undone."
-  (interactive)
-  (setq gpolonkai/last-killed-buffer-file-name (buffer-file-name))
-  (kill-this-buffer))
-
-(defun gpolonkai/undo-buffer-kill ()
-  "Undo killing the last buffer.
-
-Esentially it visits the file again."
-  (interactive)
-  (if gpolonkai/last-killed-buffer-file-name
-      (progn
-        (find-file gpolonkai/last-killed-buffer-file-name)
-        (setq gpolonkai/last-killed-buffer-file-name nil))
-    (message "The buffer last killed didn’t visit a file.")))
-
-(provide 'buf-manipulation)
-
-;;; buf-manipulation.el ends here