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Sometimes describe- or apropos- are not enough. How can I search the Emacs Lisp Reference Manual (C-h i m elisp) from within emacs?

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    As an aside, a shorter way to reach the elisp manual is C-h r TAB RET.
    – legoscia
    Oct 7, 2014 at 12:30
  • @legoscia: Uh, no. C-h r (command info-emacs-manual) reaches the Emacs manual, not the Elisp manual.
    – Drew
    Oct 7, 2014 at 19:39
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    It does. However, the first link in the top node happens to lead to the Elisp manual, which is why the additional TAB RET brings you to the right place.
    – legoscia
    Oct 7, 2014 at 19:41
  • @legoscia: C-h i 5 is shorter than both C-h r TAB RET and C-h i m elisp RET.
    – Drew
    Mar 27, 2015 at 19:39
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    C-h i 5 isn't relevant. It takes you to "lists" if you're already in the top of the elisp manual and to something arbitrary if you are at the info top level.
    – RichieHH
    Jan 7, 2020 at 8:11

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EDIT: I just found the wonderful M-x info-apropos which searches full text over all info documents and returns the relevant nodes. Seems this gem is relatively unknown.

If you use helm package from MELPA with helm-mode on, using either i (info-index) or I (info-virtual-index) pops up a helm window with the index terms. You can then use typical helm completion patterns to discover and browse the index.

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You can use elisp-index-search. I use it daily. I use it mostly when I already know a function name and want to see it in emacs lisp manual.

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  • Does this essentially do an info-apropos and jump to what it deems the best match?
    – elarson
    Oct 7, 2014 at 20:07
  • I just tried info-apropos. It seems to search all info doc, but elisp-index-search only search elisp manual. I tried to find the doc for elisp-index-search but wasn't successful. I learned about it by calling describe-key on the menu 【Help→Search Documentation→Lookup Subject in Elisp Manual…】
    – Xah Lee
    Oct 7, 2014 at 20:09
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More of a full text search but C-s (isearch-forward) will search through the whole info document if you repeat enough times. I use it mostly as a desperation measure when I can't work out the actual term that appears in the index.

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The closest I know of is searching the index by running Info-virtual-index (bound to I) from within the manual.

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In addition to what others have mentioned, Icicles facilitates browsing and searching Info manuals.

  1. Remember that i (Info-index) is your friend in Info. Start your search with it. It is typically more useful than a brute-force text search, because a human has indexed useful terms.

    Unfortunately, although i in vanilla index accepts a substring of an index entry as input (using RET), it does not provide substring, let along regexp, completion. In Icicle mode, i in Info is bound to icicle-Info-index, which provides such completion, and it also lets you filter using multiple patterns (progressive completion). It is also a multi-command, which means that with a single i invocation you can visit any number of occurrences for any number of index entries.

  2. With Icicles, you can optionally have i and other Info commands highlight a bit differently, in buffer *Completions*, completion candidates that correpond to Info nodes that you have already visited. This is handy to avoid revisiting a node that you have already consulted, when searching in different ways. It helps especially with double-entry indexing, that is, multiple index entries to the same node.

  3. In addition to index lookup, you can search an Info manual. In vanilla Emacs you can use C-s or C-M-s repeatedly to do this. This can be handy in cases where i does give you the help you want.

    With Icicles, you can limit searching to a particular set of nodes. g (Info-goto-node) accepts multi-completion input. You can provide a pattern (regexp, substring, etc.) that matches node names or a pattern that matches node content, or both. Matching a pattern against node content means searching manual content. The completion candidates shown in *Completions* are the node names.

    You can search a set of nodes or an entire manual. After you choose one of the matching nodes to visit, you can use C-M-s to find each match of the content-search pattern within the node. And just as for i, g is a multi-command, which means that you can visit any number of nodes in a single g invocation.

  4. You can create virtual books composed of different sets of nodes (even from different manuals), and save these persistently, for reuse later. Searching a smaller set of nodes (a sub-manual) can be faster.

See here for more info about Icicles Info enhancements.

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You can also use s to search the current document for the next instance of a given regular expression. Repeated presses of s-<RET> will iteratively search for the next instance of the same expression. https://www.gnu.org/software/emacs/manual/html_node/info/Search-Text.html#Search-Text

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Go to EmacsDocs.org

Go to emacsdocs.org/docs/elisp/Emacs-Lisp where they've republished the Emacs Lisp docs in a readable way and added a decent full-text search engine to query its contents.

You can find the source on GitHub at tefkah/emacs-docs.

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