Introduction

Variables are integral data storage objects in the Universal Scripting Engine.

Variable Types

There are two types of variables:

Script
Global (user-defined and built-in)

Variable Names

There are no restrictions on variable names except:

They cannot contain double-quote marks ( " ) or spaces.
UDM reserves variable names beginning with an underscore ( _ ) for its own internal (built-in) variables (see UDM - Built-In Variables). You cannot create a script variable or user-defined global variable that begins with an underscore ( _ ).

Variable Reference

To obtain the value of a variable, you must create a reference for that variable. The reference can appear anywhere in a script line. It is replaced with the value of the referenced variable.

Referencing the value of a global variable in a script is done exactly the same way as for a script variable:

$(variable_name)

For example:

Variable Attributes

In addition to accessing the value of a variable, you can access information about that variable through its attributes.

variable attribute is referenced by putting a dot ( . ) after the variable name in a variable reference. For example:

$(name.attribute)

There are two variable attributes that can be used for any variable:

exists
length

Note

Some built-in variables have attributes specific to those variables.

exists Attribute

The exists attribute expands to yes if a variable with that name exists at any scope; it expands to no if no variable with that name exists.

Note

Unlike when referencing a variable's value, an error is not issued if the exists attribute is used for a variable name that does not exist.

A Stonebranch Tip

You can use the exists attribute in combination with the if statement to determine if a variable exists (and take the appropriate action if it does):

if $(filename.exists) EQ yes
copy src=$(filename)
end

length Attribute

The length attribute expands to the length of the variable's value. If the length attribute is used for a variable that does not exist, an error is issued.

A Stonebranch Tip

You can use the length attribute in combination with the if statement to decide if a file name is too long to copy to a remote system:

if $(filename.length) LE 8
copy src=$(filename)
end

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