DTrace Actions

Actions are user-programmable statements that the DTrace virtual machine executes within the kernel. Actions have the following properties:

• Actions are taken when a probe fires

• Actions are completely programmable in the D scripting language

• Most actions record a specified system state

• An action can change the state of the system in a precisely described way. Such actions are called destructive actions. Destructive actions are not allowed by default.

• Many actions use expressions in the D scripting language