Do you sometimes wonder how to use parameters with your scripts, and how to pass them to internal functions or other scripts? Do you need to do simple validity tests on parameters or options, or perform simple extraction and replacement operations on the parameter strings? This tip helps you with parameter use and the various parameter expansions available in the bash shell.

“); } } } //–> The bash shell is available on many Linux® and UNIX® systems today, and is a common default shell on Linux. In this tip you will learn how to handle parameters and options in your bash scripts and how to use the shell’s parameter expansions to check or modify parameters. This article focuses

on bash, and the examples were all run on Linux systems with bash as the shell. However, the same expansions are available in many other shells, such as ksh, ash, or dash, and you may use them with these shells on other UNIX systems or even environments such as Cygwin. This tip builds on the tools covered in the earlier tip Linux tip: Bash test and comparison functions. Some of the material in this article is excerpted from the developerWorks tutorial LPI exam 102 prep: Shells, scripting, programming, and compiling, which covers many basic scripting techniques.

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