There are a number of basic UNIX commands that you will want to become familiar with. Some of the most basic are discussed in this section:
man: A type of UNIX help system that displays a "manual page" about a specified command. You can learn more about many of the commands in this list, or those used throughout this guide, by typing “man command,” where command is the name of the command you want to learn more about.
pwd: Short for Print Working Directory. Displays the path to the current directory.
ls (list): Displays a list of the files and directories in the current directory.
ll (long list): Displays a "long listing" of files, directories, permissions and file size in the current directory.
grep: Searches files or directories for a specific word, phrase, or file.
cd (change directory): Used to move to a different directory. If no directory is specified, it will take you to your home directory.
mkdir (make directory): Used to create a new directory.
mv (move): Moves a file into another directory, or renames a file by "moving" an existing file to a new file with a new name.
rm (remove): Removes a file or directory.
cp (copy): Makes a copy of a file or directory.
touch: Creates a new, empty file or updates the date that an existing file was last modified.
echo: Used to print text to the display, or alternately to another device or file.
more: Displays the contents of a text file, or the output of a program, and waits for you to "ask for more" by pressing the space bar if the text is larger than your display. It is one of several commands known as pagers because it breaks the displayed information up into pages. Other popular pagers include less and most.
pico: Starts the pico online text editor. An editor is a program that allows you to edit text files on your virtual server– a task that you will do often. Many beginners find pico to be the easiest editor to learn, although more experienced users often prefer the advanced capabilities provided by the vi editor, which is a bit more complex to learn.
chown: Changes ownership of a file. UNIX files and directories are “owned” by both a user and a group. Chown allows you to change both the user and group owner of a file, a directory, or a directory and its contents.
chmod: Changes permissions on a file. UNIX files and directories have “permissions” – that is, different people are allowed to have different types of access to a file or directory based on the permissions that the file or directory has been given.