While writing a shell script, there is one stage when we feel that a shell script file has become too big to read and manage. To avoid such a scenario in our shell script, it is very important to keep the script modular.
In order to keep the script modular and maintainable, you can do the following:
Create functions instead of writing the same code again and again
Write a common set of functions and variables in a separate script and then source to use it
We have already seen how to define and use a function in Chapter 3, Effective Script Writing. Here, we will see how to divide a bigger script into smaller shell script modules and then use them by sourcing. In other words, we can say creating libraries in bash.