Process started with java's Process.exec always returns exit code 0

Question

I start shell scripts with java Process.exec (for reasons), and they always return 0 exit value, regardless of exit value of script itself (which I can check by running said script in OS shell. For additional info, those scripts run gradle tasks with gradle-node-plugin. Any pointers for this issue?

Overall, setup looks as follows:

Software

• Linux desktop 4.4.0-130-generic #156~14.04.1-Ubuntu SMP Thu Jun 14 13:51:47 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux`

• java version "1.8.0_171" Java(TM) SE Runtime Environment (build 1.8.0_171-b11) Java HotSpot(TM) 64-Bit Server VM (build 25.171-b11, mixed mode)`

Shell script is executed with

Process process = Runtime.getRuntime().exec(new String[]{"sh", "-c", testScript});

Return value is obtained with test.exitValue(), and appears to be always 0.

Shell script calls gradle ./gradlew project:clean project:test.

Gradle scripts relies on gradle-node-plugin

plugins {
    id "com.moowork.node" version "1.2.0"
}

task test(type: NodeTask) {
    script = file('./node_modules/mocha/bin/mocha')
    args = ['test/sometest.js']
}

Answer 1

Gradle scripts prevent the possibility to return the exit code to the same shell, or even ending the calling shell. This is done through the use of environment variable GRADLE_EXIT_CONSOLE (an arbitrary, non-empty value is enough):

• If set: The script ends the shell and returns the exit code.
• If not set: The script returns the exit code to the calling shell, allowing it to continue processing commands.

If you are calling gradle through Runtime.exec, it creates a new shell, so you need to set that variable prior to calling the script, so you get the exit code after the shell is ended.