This article is reprinted from the book A Practical Guide to Linux Commands, Editors, and Shell Programming 3rd edition, with permission of the author and publisher ...

For many users who get started with the command line in Linux, there’s a good chance they’re using Bourne Again Shell, or Bash. Bash is the default shell on Mac OS X, and Windows users can use Bash ...

While Linux systems install with thousands of commands, bash also supplies a large number of “built-ins”—commands that are not sitting in the file system as separate files, but are part of bash itself ...