Getting Started Guide 155 to perform system administration work. When you have finished, log out and log in again using a regular user account (that you have created with your own name). If another user obtains the root password to your Linux system, that person can destroy or obtain any information about the system. Guard the root password very carefully. If you are logged in with your regular user account name and you need to com- plete a system administration task, you can use the substitute user feature to change to the root user temporarily. You must know the root password to use this command. su - When you have finished completing the system administration tasks, use the exit command to return to working as a regular user.(The dash shown after the su is recommended. It causes the root user’s configuration files to be read, so the shell environment is set up properly.) See also login, users Scripts Scripts are programs that are written in a more human-readable form. Rather than being compiled into a binary file, scripts remain readable and alterable (if you have sufficient file access rights). To see a script, open the file in a text editor. Don’t change the script file unless you have learned what the commands are for. A text file that is intended as a script requires that • The first line of the script indicates what program should be used to exe- cute the script. • The text file containing the script be marked with the execute file permis- sion for the users who need to run the script. (see access rights) Scripts are used for many tasks in Linux, including determining how the system starts, what programs are launched, and what capabilities are part of each user’s environment. Scripts of many different types are used by Linux. Some scripts are executed by the command line interpreter--the shell. Others use a special interpreter just for running scripts, such as perl or python.