ZIO learning - race several sub-command processes / published by https://github.com/dacr/code-examples-manager #56f16fa2-8f7e-4046-a2a5-bf19fcba2623/cac40bc0305a9c9403782625b7e06314f0c36247

zio-learning-process-4-race.sc

// summary : ZIO learning - race several sub-command processes
// keywords : scala, zio, learning, process, commands, pure-functional, @testable
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : 56f16fa2-8f7e-4046-a2a5-bf19fcba2623
// created-on : 2022-07-20T20:24:11+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "dev.zio::zio-process:0.7.2"
// ---------------------

import zio.*
import zio.process.*
import zio.stream.ZPipeline.{utf8Decode, splitLines}

object Encapsulated extends ZIOAppDefault:
  def run =
    for
      process1    <- Command("vmstat", "1", "10").redirectErrorStream(true).run
      stream1      = process1.stdout.stream.via(utf8Decode >>> splitLines)
      outputFiber1 = stream1.runCollect

      process2    <- Command("echo", "KO-KO-KO-KO-KO").redirectErrorStream(true).run
      stream2      = process2.stdout.stream.via(utf8Decode >>> splitLines)
      outputFiber2 = stream2.runCollect

      output <- outputFiber1.raceFirst(outputFiber2).catchAll(err => ZIO.succeed(Chunk(err.toString)))

      status1 <- process1.exitCode
      _       <- process1.killTree.ignore

      status2 <- process2.exitCode
      _       <- process2.killTree.ignore

      text = output.mkString("\n")
      _   <- Console.printLine(s"status1 = $status1 - status2 = $status2 - Gotten content = $text")
    yield ()

Encapsulated.main(Array.empty)