31.6.1 Info Documentation Lookup

For C, Lisp, and other languages that have documentation in Info, you can use C-h S (info-lookup-symbol) to view the Info documentation for a symbol used in the program. You specify the symbol with the minibuffer; the default is the symbol appearing in the buffer at point. For example, in C mode this looks for the symbol in the C Library Manual.

The major mode determines where to look for documentation for the symbol—which Info files to look in, and which indices to search. You can also use M-x info-lookup-file to look for documentation for a file name.

This feature currently supports the modes AWK, Autoconf, Bison, C, Emacs Lisp, LaTeX, M4, Makefile, Octave, Perl, Scheme, and Texinfo, provided you have installed the relevant Info files, which are typically available with the appropriate GNU package.