Mac OS is the computer operating system for Apple Computer’s Macintosh line of personal computers and workstations. A popular feature of its latest version, Mac OS X , is a desktop interface with some 3-D appearance characteristics. OS X has a modular design intended to make it easier to add new features to the operating system in the future. It runs UNIX applications as well as older Mac applications.

The Mac Terminal Commands Cheat Sheet
Our mega cheat sheet of Mac terminal commands provides a great reference for all the important commands you should know.
grep “ Output all occurrences of inside (add -i for case insensitivity)
grep -rl “ Search for all files containing inside
cat Output the content of
less Output the contents of using the less command that supports pagination and more
head Output the first 10 lines of
> > Appends the output of to
> Direct the output of into
| Direct the output of to