Most Emacs hackers quickly memorize the myriad of help commands available to them in Emacs. Among them, the humble M-x apropos command, a full text regexp search command that searches all known Lisp symbols (functions, variables - you name it) and returns a list of matches.
In fact, there’s an apropos command for all occasions. They’re must-have commands if you can’t quite find what you are looking for. To find them all, why not use apropos: C-h a apropos.
Nestled among all the other apropos commands is M-x info-apropos, a full text search for Emacs’s documentation browser, info (C-h i.) It’s not limited to just your Emacs documentation either. The info-apropos command handily searches all Info manuals Emacs is aware of and presents the matches as hyperlinked entries to their respective manual pages.
It’s not a commonly needed command, but when you do need it, you’ll be glad it’s there.
