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-modeetc. 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 “xyz-mode”, the command to turn it on is usually named “xyz” or “xyz-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]
List Major Modes
Alt+x apropos-command, then type “-mode”. (it's not a complete list, because some major mode's name do not end in “mode”)
[see Emacs: Search Function/Command, List Commands]
Or, look at the variable auto-mode-alist.
- auto-mode-alist
- Alist of file name patterns vs corresponding major mode functions. [see Emacs: Show Variable Value]
