What is a man page?

A man page (short for manual page) is the traditional form of software documentation on a Unix-like OS like Ubuntu. For the vast majority of commands and programs there's a man page which lists its options and explains its usage.

How can I find and view man pages?

Offline in a terminal

Man pages are automatically installed on your system together with the commands they describe. To view and search man pages there's the command man:

man mv

displays the man page of mv while

man -k mv

searches names and short descriptions of all installed man pages for the string mv. POSIX Extended Regular Expressions are allowed and it's a search, so this will also find e.g. git-mv and semver, if you want to search exactly mv use ^mv$ instead.

See What is the difference between `man` and `man (#)`? to read about man page sections. For more information read man's man page. ;)

How can I influence how a man page is displayed?

The default program to display man pages is less. This so-called pager provides a helpful search function, just enter / followed by the search term, e.g.

/--version

and press Enter. This will mark every finding and scroll to the first one. Press N to go to the next finding and ⇧ Shift+N to go to the previous one (see How can I search within a manpage?). For a list of commands press H, to exit less press Q.

Beside less there are other pagers available: pg, most and w3m just to list three. I recommend most: It comes with a very useful coloring of key words making a man page much easier to read and navigate, see for yourself:

To view a man page in a different than your default pager use the -P option, e.g.:

man -P most mv

If you want to change the default pager manpages are displayed with you have two options:

• change the default pager solely of man

  export MANPAGER=most
  

  To make the change persistent add this command to your ~/.bashrc file.

• change the default pager of your whole system

  sudo update-alternatives --config pager
  

_{Fans can even (ab)use vim as the MANPAGER, see this article written by muru.}

Man pages are displayed in the font specified in your terminal emulator settings. If you work with the terminal regularly you might want to change this font; I can only recommend Hack – a typeface designed for source code, see the screenshot above for its beauty.