CmdID / Commands
Search the manual pages for names and descriptions. tldr-pages
On several platforms
Opens CmdID with your command. It is read in your browser and sent nowhere.
Search for a keyword using a regex
apropos regex
Search without restricting the output to the terminal width (long output)
apropos --long regex
Search for pages that match all the regex given
apropos regex_1 --and regex_2 --and regex_3
man