Normalmente, volto ao google em tais circunstâncias, mas tento usar man -K
.
Da página man man:
-k, --apropos
Equivalent to apropos. Search the short manual page descriptions for keywords and display any matches. See apropos(1) for details.
-K, --global-apropos
Search for text in all manual pages. This is a brute-force search, and is likely to take some time; if you can, you should specify a section to reduce the number of pages that need to be searched. Search terms may be simple strings (the default), or regular expressions if the --regex option is used.