Summary
The bash shell script allows you to string commands together into a script. The most basic way to create a script is to separate multiple commands on the command line using a semicolon. The shell executes each command in order, displaying the output of each command on the monitor.
You can also create a shell script file, placing multiple commands in the file for the shell to execute in order. The shell script file must define the shell used to run the script. This is done in the first line of the script file, using the #! symbol, followed by the full path of the shell.
Within the shell script you can reference environment variable values by using a dollar sign in front of the variable. You can also define your own variables for use within the script, and assign values and even the output of a command by using the backtick character or the $() format. The variable value can be used within the script by placing a dollar sign in front of the variable name.
The bash shell allows you...