emacs - How can I simply grep-search through all avaliable documentation text? -

i'm sure emacs' self-documentation great , everything, can't seem understand how should used, , since googling need matter of seconds typically resort – not satisfying! (and impossible while offline, rather while travelling etc..)

which makes me wonder: why can not "google" through of locally installed documentation, give me anything therein looks string i'm searching for? suppose possible grepping through files command line, can't way it.

apropos sounds should that, doesn't... i've never found command didn't know anyway.

here couple of previous answers i've written may pointed in right direction. there isn't single (default) command searches of documentation sources, that's going okay of time.

(i've never investigated third-party libraries in area, mind; there might things out there take more all-encompassing approach searching documentation.)

• how started using emacs' documentation?
• emacs: open specific info section
• how efficiently search info documentation?

m-x elisp-index-search , m-x emacs-index-search excellent first ports of call.

m-x info-apropos less well-known useful, searches indices of known info files on system. it's correspondingly slower other functions, of course.

above all, make sure know how use info reader! (see links of more important details).

i use following bindings @ apropos commands (and sure read c-h v apropos-do-all, behaviour of can triggered supplying prefix argument commands mentions).

;; custom 'apropos' key bindings (global-set-key (kbd "c-h c-a") 'my-apropos-prefix) (define-prefix-command 'my-apropos-prefix nil "apropos (a,d,f,i,l,o,v,c-v)") (define-key my-apropos-prefix (kbd "a")   'apropos) (define-key my-apropos-prefix (kbd "c-a") 'apropos) (define-key my-apropos-prefix (kbd "d")   'apropos-documentation) (define-key my-apropos-prefix (kbd "c")   'apropos-command) (define-key my-apropos-prefix (kbd "f")   'apropos-command) (define-key my-apropos-prefix (kbd "i")   'info-apropos) (define-key my-apropos-prefix (kbd "l")   'apropos-library) (define-key my-apropos-prefix (kbd "o")   'apropos-user-option) (define-key my-apropos-prefix (kbd "v")   'apropos-variable) (define-key my-apropos-prefix (kbd "c-v") 'apropos-value) 

and lot of use out of these well:

(global-set-key (kbd "c-h c-l") 'find-library) (global-set-key (kbd "c-h c-f") 'find-function) (global-set-key (kbd "c-h c-k") 'find-function-on-key) (global-set-key (kbd "c-h c-v") 'find-variable) 

these functions looking @ source code, , although describe-* commands more useful when comes documentation, it's not uncommon libraries not yet covered info manuals have commentaries @ beginning of source code. above functions & bindings therefore make convenient shortcuts visiting source code check such documentation.

there are, of course, heap of default bindings on c-h prefix (or <f1> if prefer), including (but not all!) of aforementioned describe-* commands. type c-h c-h , do read through of options lists. might not care about, , might decide rather more interesting last time looked.

check m-x apropos-command ret ^describe- ret well.

lastly, @ "help" menu! "search documentation" sub-menu in particular, above, take note of other items well.

extra-lastly, find cause actually grep emacs sources every , then. if have uncompressed, m-x rgrep friend usual. if, however, (uncompiled) elisp gzipped, want m-x zrgrep (the existence of news people).