Publisher's Synopsis
Bash ScriptingThink of a script for a play, or a movie, or a TV show. The script tells the actors what they should say and do. A script for a computer tells the computer what it should do or say. In the context of Bash scripts we are telling the Bash shell what it should do.A Bash script is a plain text file which contains a series of commands. These commands are a mixture of commands we would normally type ouselves on the command line (such as ls or cp for example) and commands we could type on the command line but generally wouldn't (you'll discover these over the next few pages). An important point to remember though is: Anything you can run normally on the command line can be put into a script and it will do exactly the same thing. Similarly, anything you can put into a script can also be run normally on the command line and it will do exactly the same thing.You don't need to change anything. Just type the commands as you would normally and they will behave as they would normally. It's just that instead of typing them at the command line we are now entering them into a plain text file. In this sense, if you know how to do stuff at the command line then you already know a fair bit in terms of Bash scripting.It is convention to give files that are Bash scripts an extension of .sh (myscript.sh for example). As you would be aware (and if you're not maybe you should consider reviewing our Linux Tutorial), Linux is an extensionless system so a script doesn't necessarily have to have this characteristic in order to work.
