In rule files, you can use variables to keep track of numbers and text strings. A variable name can consist of any sequence of letters, digits, and, underscores provided the first character is not a digit.
Variables do not have to be specially defined, and you can give them a value using an equals sign. For example, the following might specify a counter value for the subsequent repetition of a command:
For maximum flexibility, variables can be set to a list of values. The list is specified by putting all the elements of the list in brackets. So, for example, the following could be used to make the variable editors equal to a list of the filenames of all the editors on the system:
editors=(vi xedit ed)
Variables are local to an executing script unless prefixed with a ``:''.