A command is an interactive function, i.e. a function that can be called using M-x, or bound to a key sequence.

• C-x is called character extend. It is followed by one character;
• M-x is called command extend. It is followed by a long name.

Cancelling

• C-g: cancel command.
• ESC ESC ESC: either quit or abort.

Repeating

• C-x z: Repeat previous command.
• C-x z z z: Repeat previous command three times.
• M-x repeat-complex-command: Edit and re-evaluate the last complex command, i.e. the last one that used the minibuffer.

More

C-x uses a keymap where the bindings are defined. This keymap is stored in ctl-x-map. To see this map, just use C-h v ctl-x-map. See help for more details on Help commands.

Minibuffer

Change history-length variable to incrase history size. Default is 30.

• C-M-b: Go to previous path separator;
• C-M-f: Go to next path separator.
• M-p: Also up arrow. Previous command in history.
• M-n: Also down arrow. Next command in history.
• C-r: Search back in command in history
• M-x list-command-history: List commands in history. Use x to execute one of the commands in the list.