- Qbs Manual
- Qbs 2.1.1

Parameters ◦ Product

# Probe

Locates files outside the project. More...

- List of all members, including inherited members

## Properties

- condition : bool
- configure : script
- found : bool

## Detailed Description

Probe items can appear inside Product, Project and ModuleProvider items. They are run prior to building, for instance to locate dependent headers, libraries, and other files outside the project directory whose locations are not known ahead of time. Probes can be parameterized via their properties and typically store results in properties as well. These results are then retrieved via the Probe's id, which is mandatory:

     Product {
         Probe {
             id: valueCalculator
             property string parameter: "whatever"
             property int value
             configure: {
                 value = Utils.calculateValue(parameter); // Expensive operation
                 found = true;
             }
         }
         property int theValue: valueCalculator.value
     }

Note: Because Probes often invoke external processes, which is relatively expensive compared to evaluating normal properties, their results are cached. To force re-evaluation of a Probe, you can supply the --force-probe-execution command-line option to the build command.

## Property Documentation

condition : bool

Determines whether the probe will actually be run.

Default: `true`

configure : script

A script that is executed when the probe is run.

found : bool

Indicates whether the probe was run successfully. Set by configure.

Default: Undefined

Parameters ◦ Product