Get the Output of an External Command into an variable for further use.

build.gradle.kts

import java.io.ByteArrayOutputStream

tasks.register("gitCommit") {
    group = "com.linux"
    description = "Get The last git commit"
    doLast {
        val output = ByteArrayOutputStream().let { os ->
            exec {
                commandLine("/usr/bin/git rev-parse --verify HEAD".split(" "))
                standardOutput = os
            }

            os.toString()
        }

        println(output)
    }
}