Linux Shell Scripting Cookbook - Second Edition

Playing with variables and environment variables

Variables are essential components of every programming language and are used to hold varying data. Scripting languages usually do not require variable type declaration before its use as they can be assigned directly. In Bash, the value for every variable is string, regardless of whether we assign variables with quotes or without quotes. Furthermore, there are variables used by the shell environment and the operating environment to store special values, which are called environment variables. Let us look at how to play with some of these variables in this recipe.

Getting ready

Variables are named with the usual naming constructs. When an application is executing, it will be passed a set of variables ...