Shell Scripting: Expert Recipes for Linux, Bash, and More

Summary

A lot of different shells are available on Unix and Linux systems; this chapter looked at some of the most popular. They are all superficially very similar in that they all provide an interactive command-line interface to the system, and they all run basic shell scripts in the same way, but in practice there is a world of difference between them, which can make porting scripts from one shell to another very time-consuming and cumbersome.

Understanding the range of differences between systems is key to writing portable and robust shell scripts, as well as being comfortable with any customer’s system however it is configured. Also, using aliases, prompts, and profile settings can make your home systems much more familiar and therefore productive, whether that is on a home network, an intranet, or company-wide.

The site http://en.wikipedia.org/wiki/Comparison_of_command_shells has an exhaustive comparison of all of the major shells available.

This chapter marks the end of the more theoretical part of this book. Part II looks in more depth at the individual tools available in Unix and Linux. Part III looks into uses of particular shell features more closely, and provides various practical recipes for typical real-life tasks.