Emacs: Search Documentation, List Commands

By Xah Lee. Date: 2016-08-31. Last updated: 2022-05-14.

Search for Function

Alt+x apropos-command: Search command by name.
Ctrl+u Alt+x apropos-command: Search both function and command names. (In emacs, “commands” are a subset of “functions”. Commands are functions that can be called interactively (by typing Alt+x).)
Alt+x apropos-variable: Search variable names.
Alt+x apropos-value: Search variable values.
Alt+x apropos: Search all symbols (commands, functions, variables, faces).

Emacs is bundled with emacs lisp manual in “Texinfo” format. [see Emacs: View Info Page]

Alt+x elisp-index-search: Find a function's documentation in the emacs lisp manual. (info "(elisp) index")
Alt+x emacs-index-search: Find a function's documentation in the emacs manual. (info "(emacs) index")