9.13 Writing Shell Scripts

So far we have focused exclusively on the interactive nature of the Bash shell. By interactive we mean manually entering commands at the prompt one by one and executing them. In fact, this is only a small part of what the shell is capable of. Arguably one of the most powerful aspects of the shell involves the ability to create shell scripts. Shell scripts are essentially text files containing sequences of statements that can be executed within the shell environment to perform tasks. In addition to the ability to execute commands, the shell provides many of the programming constructs such as for and do loops and if statements that you might reasonably expect to find in a scripting language.

Unfortunately a detailed overview of shell scripting is beyond the scope of this chapter. There are, however, many books and web resources dedicated to shell scripting that do the subject much more justice than we could ever hope to achieve here. In this section, therefore...