how to run shell script from Gradle and wait for it to finish

Question

I'm running a shell script from gradle, the issue is that the shell script is running some prerequisites that I need to be run before gradle continues.

I tried the following but seems like gradle is opening another child process for the shell script

sleep.sh
echo 'hi1'
sleep 1
echo 'hi2'
sleep 10
echo 'bye'


Gradle:
task hello3(type: Exec) {
println 'start gradle....'
    commandLine 'sh','sleep.sh'
println 'end gradle....'
}



Result:
start gradle....
end gradle....
:hello3
hi1
hi2
bye

Answer 1

Your problem is your the println statements are executed when Gradle parses the build.gradle file, not when it executes the task.

You should move your println statements to doFirst and doLast as follows to make things clear:

task hello3(type: Exec) {
  doFirst {
    println 'start gradle....'
  }
  commandLine 'sh','sleep.sh'
  doLast {
    println 'end gradle....'
  }
}

I believe, Gradle actually waits for the script to finish before doing anything else, so you do not need to do anything special to make it wait.

Gradle will always start your shell script in a child process.