Emacs Cheatsheet - Keybindings, Buffers & Org Mode

C-g is Emacs' universal abort: it breaks out of any submode or waiting prompt — an incremental C-s search, minibuffer input after M-x, a running C-x ( macro recording, a long-running command in progress. Since pressing it is never destructive (real deletion still needs an explicit C-w or C-d), treat it as a safe exit you can hit at any time. Inside the minibuffer, C-g is also how you abandon what you have typed instead of trying to undo your way out.

Emacs does not paste from a system clipboard: it keeps a kill ring of recent kills. Press C-Space to set the mark, move the cursor to form a selection, then C-w kills it (removing the text and pushing it onto the ring) while M-w copies it and leaves the text alone. C-y yanks the most recent kill, and M-y cycles back through older ones. So the reliable way to relocate a block is C-w, move the cursor, C-y — not C-w and then walk to the target. The ring is global, so kills stay available across buffers and files.

Start recording with F3 or C-x (, perform the whole edit sequence once (go to line start, set the mark, select to end of line, delete, insert the replacement), and stop with F4 or C-x ). Replay with C-x e; to apply the macro 100 times type the numeric prefix first: C-u 100 C-x e. If you change your mind mid-recording, C-g aborts without leaving a half-built macro. Macros suit purely mechanical, branch-free repetitions; once the pattern needs a conditional, M-x replace-string or M-x replace-regexp is the better tool.

They solve different problems. Buffer switching (C-x b) swaps the content of a single window, which is what you want when moving between a few files. Splitting keeps several buffers visible at once so you can watch a parser result or program output update while you edit another file. The window set: C-x 2 splits vertically, C-x 3 horizontally, C-x o moves to the other window, C-x 1 leaves only the current one, C-x 0 deletes it, and C-x ^ / C-x } grow the current window taller or wider. Bookmarks via C-x r m and C-x r b then jump you back to those positions quickly.

It depends on how sure you are of the matches. M-x replace-string and M-x replace-regexp sweep the whole buffer and write immediately, which suits a clear, uniform pattern. M-% prompts you once per match — y to replace, n to skip, N to replace the rest, q to quit — so you can exclude the occasional hit that should stay. Reach for replace-regexp when the pattern needs metacharacters (quantifiers, character classes, anchors); for literal text replace-string is faster and safer. In either case, run a C-r search first to confirm the hit range.