The Unix or GNU/Linux ‘apropos’ command is similar to AproposMode, but it shows a list of Unix or GNU/Linux manual (‘man’) pages (see ManMode) matching the search instead of functions and variables. Library sys-apropos.el is a simple Emacs interface for this command.

In the 2002 version sys-apropos-line-regexp is a bit too tight and you may find some pages not displayed, including Perl modules, pages with “.” dots, and alphanumeric sections like “(3ncurses)”. Here’s a more relaxed setting which should catch everything

    (setq sys-apropos-line-regexp
      "^\\([^ \t]+?\\)[ \t]*(\\([0-9].*?\\))[ \t-]+\\(.*\\)")

See also ManMode where “M-x man -k pattern” does a similar apropos run and display.