The Command Line Interface (CLI) is the fundamental method of interacting with Linux/Unix/OS X systems. When Linux and Unix were first developed, the CLI was the only way of communicating with the system.
Today, with the many Graphical User Interfaces ( GUIs) available, fewer users are now being exposed to what can be done from the command line. In particular, users of OS X systems are commonly ignorant of what can be done through their terminal.
The intent of this page and the posts that it references are to introduce the new Linux user and the OS X user to what can be done through the CLI.
What are CLI Commands
Commands that are entered at the command line are simply programs that have been developed over the years and are now part of the Unix/Linux/OS X distribution that you are using. There are hundreds of commands, some you will use often, others you may never use.
|cat||*||*||concatenate and print file|
|chgrp||*||*||change group ownership|
|ls||*||*||list directory contents|
|man||*||*||format and display the on-line manual pages|
|pwd||*||*||print working directory|
|sudo||*||*||execute a command as another user|