Emacs is a class of text editors that work on a wide variety of platforms characterized by adjustability. The editing commands in Emacs can be defined by the installed packages or can be set by the user. The user can also combine commands into macros to automate repeated controls.
Emacs development began in 1975, and it is continuously developed today also. Emacs are very popular with programmers, as they can easily define their new functionalities, where on other editors they can do that only through APIs. Being based on a single-threaded Lisp implementation, Emacs offers the comfort of functional language combined with a simple yet powerful interface modeling design.
The most popular version of Emacs is GNU Emacs:
GNU Emacs is an extensible text editor created by Richard Stallman. Emacs is not just a text editor. Emacs can also compile programs, run and debug applications, read e-mail and so on.
Emacs extensions are written in the Lisp programming language. There are multiple variants available, one for the Linux terminal and one for Windows called XEmacs.
The Emacs screen consists mainly of several windows, called buffers. Some buffers may not be visible, and one of them is always called the current one by the user.
The Emacs editor can work with multiple open files simultaneously, each one in a different buffer. Each buffer is displayed in a window.
Also, each window contains a text line on the bottom, indicating various useful buffer information: when it was modified, line and column count, and so on.
The Emacs screen also contains a mini-buffer, mainly an area where emacs reports command results, partial keystrokes, and so on.
On the top edge of the screen is the Emacs menu.
In Emacs, two unique keys are used, namely Control and Meta, which are used only in combination with other keys. Control matches the Control key on most keyboards and the Alt key on PCs.
The code generated by the Meta key along with the other key can be obtained (for example, in the case of remote connections) by pressing the Escape key (ESC), then the corresponding key.
For this reason, the Escape key is also called metafy. To follow the conventions, we will also follow the equivalent notation where C is Control and M is Meta.
Essential Emacs keys
C- @ Set Mark
M-w Copy region in the kill ring
C-a Beginning of line
C-x 0 Delete this window
C-x 1 Keep only this window
C-b Back one character
C-x 2 Split window vertically
M-b Backward word
C-x 3 Split window horizontally
C-d Delete one character
C-x b Select buffer by name
M-d Delete word
C-x C-b List all buffers
DEL Delete previous character
C-x C-c Exit
M-DEL Delete previous word
C-x C-f Find a file and load it
C-e End of line
C-x C-w Write in the file (save as)
End of sentence
C-x d Directory editor (file manager)
C-f Forward one character
C-x k Kill this buffer
M-F Forward word
C-x Move to other windows
C-g Abort current command
C-x s Save all buffers
C-h i Info help system
C-x Undo
C-k kill line
C-y Yank last killed text
Kill sentence
M-y Yank previous from kill ring
C-l Refresh screen
C-z Stop emacs
C-n Next line
M- / Fill word automatically
C-p Previous line
M– Same as C-u -1
C-r Incremental search backward
M-c Capitalize word
C-s Incremental search forward
M-h Make this paragraph region
C-SPC Set mark here
M-l Lowercase word
C-t Transpose characters
M-q Fill paragraph
M-t Transpose words
M-SPC Delete space around point
C-u The numerical argument follows
M Uppercase word
C-v Page down
M-x Type command by name
M-v Page up
M- <Beginning of the buffer
C-w Kill region
M-> End of buffer