Is there a command to search for a string within all man pages installed in the man-db

Question

I know that if I can't remember a command I can just look it up on Google. But this should be possible from the shell itself. If I could output all the man-pages, I could run a grep on them and find what I was looking for.

Is there a simple command line man-search-engine out there that indexes all the words in all the man pages and lets you search through the descriptions? If not, how hard would it be to develop one?

Answer 1

I think you might be looking for the -k option to man; see also apropos.

Answer 2

If you want to search the entire text of the man pages instead of just the short descriptions, the correct answer is man -K (upper case K) or man --global-apropos

The default is to search for literal strings unless --regex is used

Answer 3

apropos or man -k is the command to search for a string in man pages. But unfortunately, the classic implementations search only the NAME section, which is quite limiting.

NetBSD's apropos implementation does full text search through the entire body of the man pages.

There is web based version of it as well: man-k.org