If I'd like to have the

standardOutput

of this task

val effXml by registering {
    workingDir = projectDir.parentFile.parentFile
    commandLine("sh", "-c", "mvn -B -f pom.xml help:effective-pom")
    standardOutput = ByteArrayOutputStream()
}

as the input of another one, there is no other way to use the classic Task Api with the annotation tags and go through a File, isn't?

Please reread your question and make sure you didn't mistype, because to me in is current state it doesn't make too much sense

output, sorry

Still not fully sure what you mean with the last sentence, but if I understood correctly, what hinders you to use outputs.file to register the result file as output ad-hoc and using the task as input for another task?

I was hoping in some Gradle magic 😄

That does what?

to grab the standardOutput as task output, but as far as I got, the only automatic output is the

ExecResult

You don't have a task of type

Exec

but a task of type

Task

you don't have any outputs. You just call the

exec

method at runtime of the task. And even if you would use a task of type

Exec

I don't think what you seek for is possible. Write the result to a file and use that as input, then you can also make the task and to be up-to-date.