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Using Standard String Templates

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Several consumers, such as the Active Script Event Consumer or the Command Line Event Consumer, have string properties with the Template qualifier. These properties use standard string templates to construct a string that is configured in part by the consumer instance and in part by an event. The structure of a standard string template is similar to the Microsoft Windows environment variable specification.

The following list shows some examples of the template language:

  • The string "Some text here" always produces the string "Some text here".
  • "%CPUUtilization%" always produces the value of the CPUUtilization property of the event being delivered. If the property is not a string, it is converted to a string; for example, "90" or "TRUE".
  • "The CPU utilization of this processor is %CPUUtilization% at this time" embeds the value of the CPUUtilization property of the event into the string, producing something like, "The CPU utilization of this processor is 90 at this time".
  • "%TargetInstance.CPUUtilization%" retrieves the value of the CPUUtilization property in the embedded instance of the TargetInstance property.
  • "%%" produces a single % sign.
  • If the property being retrieved is an array, the entire array is produced in the following format: "(1,5,10,1024)". If there is only one element in the array, the parentheses are omitted. If there are no elements in the array, "()" is produced.
  • If a property is an embedded object, the MOF representation of the object is produced (similar to the IWbemClassObject::GetObjectText method).
  • If a property of an embedded array of objects is requested, it is treated as a property with an array value. For example: %MyEvents.TargetInstance.DriverLetter% could produce '("C:","D:")' if MyEvents is an array of embedded instance modification events.

String Literals

Anything inside a pair of quotes is considered a string literal and will not be replaced.

The following example shows the string that the compiler sees for "CPU utilization is %CPUUtilization%".

CPU utilization is %CPUUtilization%

This string produces the following output.

CPU utilization is 90

On the other hand, the string "CPU utilization is \"%CPUUtilization%\"" is seen by the compiler as follows.

CPU utilization is "%CPUUtilization%"

This string produces the following output, with no variable substitution.

CPU utilization is "%CPUUtilization%"

Monitoring and Responding to Events with Standard Consumers