UNIX: The Complete Reference, Second Edition, 2nd Edition

CHAPTER 20Shell Scripting

By now you are familiar with using the shell interactively to enter commands. In addition to being a command interpreter, however, the shell is a full-fledged programming language. A program written in the shell language (or, as some users would say, written “in shell”) is often called a shell script. A shell script is just a sequence of commands that have been saved in a file. In fact, any commands you might enter at the command line can be made into a script, and any script that you might write can also be executed just by entering the commands in the file at the command line. This makes basic shell programming very easy to learn, even if you have never programmed before. The shell configuration files (such as your ...