Environment variables

Unix shell provides environment variables. To see the entire list of environment variables, use:

set

These environment variables can be used by the shell, programs or commands.

For example, the $PS1 variable is used by the shell to display the prompt. To change your prompt, you can try:

PS1='xxx>>'

The environment variable $PATH is a list of directories separated by a colon. It is used by the shell to find the file corresponding to a command.