13.2.4.1 Using Variables

The name of a variable must be a sequence of letters, digits, underscores and dashes, but it may not begin with a digit or dash. Notice, that in contrast to the majority of programming languages, use of dashes (minus signs) is allowed in user names. This is because traditionally RADIUS attribute names contain dashes, so extending this practice to variable names makes radtest programs more consistent. On the other hand, this means that you should be careful when using minus sign as a subtraction operator (see minus-ambiguity). Case is significant in variable names: a and A are different variables.

A name of a variable may coincide with one of radtest reserved keywords. See section 13.2.3 Reserved Keywords, for description on how to use such variables.

A few variables have special built-in meanings (see section 13.2.4.6 Built-in Variables). Such variables can be assigned and accessed just as any other ones. All built-in variables names are entirely upper-case.

Variables are never declared, they spring into existence when an assignment is made to them. The type of a variable is determined by the type of the value assigned to it.