Emacs: What is Major Mode

What is a Major Mode

Each buffer/file is associated with one major mode.

A “major mode” is a collection of emacs behaviors, designed for specific task.

Example of major modes:

• programing languages: emacs-lisp-mode, python-mode, ruby-mode, js-mode etc.
• dired [see Emacs: File Manager, dired]
• shell [see Emacs: Run Shell in Emacs]
• image-mode [see Emacs: View Image File]
• eww [see Emacs: Eww Web Browser]

Switch to a Major Mode

Each major mode typically has a associated command. e.g. Alt+x shell. If a mode is named “xx-mode”, the command to turn it on is usually named “xx” or “xx-mode”.

• To switch to a major mode, just Alt+x major_mode_command_name
• To turn “off” a major mode, just switch to another major mode. There's always one major mode on.

A proper major mode is usually automatically turned on when you open a file. [see Emacs: Set Default Major Mode]

fundamental-mode

The most basic major mode is fundamental-mode. If you want to “turn off” all major modes, type Alt+x fundamental-mode.

What is current major-mode

Current major mode's nick name shows in the mode line:

The current major mode's actual emacs lisp symbol is stored in a variable major-mode . This is more useful for emacs init and coding.

major-mode

A Buffer Local Variable . Value is Symbol for current buffer's major mode. [see Emacs: Show Variable Value, List Variables]