Coreutils and getting help
Run the following command in bash,
$ info coreutils
Alternatively, go on emacs (if it is installed), and Ctrl-h i, to see an overview of help topics. The info within emacs is more colorful than the standalone info program.
To get the manpage for bash, enter the following
$ info bash
which is a highly recommended read. To open the manpages on emacs, enter Alt-x man or Alt-x woman.
The man command in Linux does something similar, however the navigation is vi-like, unlike the info command which is emacs-like. For example in the man navigation, j and k to go up and down. / to search. In the info navigation, Ctrl-v goes downward, Alt-v upward, and Ctrl-s for search. Press F10 to see more options and in emacs.
Source Code
The source code for gnu coreutils is located here. Enjoy!