Below are the different goals and the minimalist configurations of the Help Plugin.
The active-profiles goal is used to discover which profiles have been applied to the projects currently being built. For each project in the build session, it will output a list of profiles which have been applied to that project, along with the source of the profile (POM, settings.xml or profiles.xml).
You can execute this goal using the following command:
# mvn help:active-profiles
Note: you could also use the output parameter to redirect output to a file.
The all-profiles goal is used to discover all available profiles under the current project.
You can execute this goal using the following command:
# mvn help:all-profiles
Note: you could also use the output parameter to redirect output to a file.
The describe goal is used to discover information about Maven plugins. Given either a plugin or a groupId, an artifactId and optionally a version, the goal will lookup that plugin and output details about it. If the user also specifies which goal to describe, the describe goal will limit output to the details of that goal, including parameters.
You can execute this goal using the following command:
# mvn help:describe -DgroupId=org.somewhere -DartifactId=some-plugin -Dversion=0.0.0
Note: you could also use the output parameter to redirect output to a file.
Refer to Configuring Describe Goal for more information about its configuration.
The effective-pom goal is used to make visible the POM that results from the application of interpolation, inheritance and active profiles. It provides a useful way of removing the guesswork about just what ends up in the POM that Maven uses to build your project. It will iterate over all projects in the current build session, printing the effective POM for each.
You can execute this goal using the following command:
# mvn help:effective-pom
Note: you could also use the output parameter to redirect output to a file.
The effective-settings goal is used to view the settings that Maven actually uses to run the build. These settings are a result of merging the global file with the user's file, with the user's file taking precedence.
You can execute this goal using the following command:
# mvn help:effective-settings
Note: you could also use the output parameter to redirect output to a file.
The system goal is used to view the system information like system properties and environment variables.
You can execute this goal using the following command:
# mvn help:system
Note: you could also use the output parameter to redirect output to a file.
You could use this interactive goal to evaluate some Maven expressions. To do it, just call the help:evaluate goal:
# mvn help:evaluate -Dartifact=org.apache.maven.plugins:maven-help-plugin ... [INFO] [help:evaluate] [INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?: ${project.artifactId} [INFO] maven-help-plugin [INFO] Enter the Maven expression i.e. ${project.groupId} or 0 to exit?: ${project.none} [INFO] null object or invalid expression ...
The artifact parameter refers to ask expressions on the artifact POM. If omitted, the evaluate goal uses the current pom.
You could ask for all Maven expressions listed in the Javadoc of the PluginParameterExpressionEvaluator class.