scalaでinteractiveなshellコマンドを実行する

lispでやってるのを見てscalaだとどんな感じになるのかな？と思って調べた
この辺を参照
https://stackoverflow.com/questions/30103040/interact-i-o-with-an-external-process-in-scala
https://github.com/scala/scala/blob/99a82be91cbb85239f70508f6695c6b21fd3558c/src/scaladoc/scala/tools/nsc/doc/html/page/diagram/DotRunner.scala

import java.io._
import scala.sys.process._


object Main extends App {
  val procIO = new ProcessIO(inputFn(_), outputFn(_), outputFn(_))
  val processBuilder = Process("/bin/bash")
  val process = processBuilder.run(procIO)

  private[this] def inputFn(stdin: OutputStream): Unit = {
    val writer = new BufferedWriter(new OutputStreamWriter(stdin))
    while (true) {
      val in = io.StdIn.readLine()
      writer.write(in + "\n")
      writer.flush()
      if (in == "exit") {
        return
      }
    }
    stdin.close()
  }
  private[this] def outputFn(stdOut: InputStream): Unit = {
    val reader = new BufferedReader(new InputStreamReader(stdOut))
    var line = reader.readLine
    while (line != null) {
      println(line)
      line = reader.readLine
    }
    stdOut.close()
  }
}

lispと違ってscalaだとあまり使う機会ないけどね〜

---

おまけ

val processBuilder = Process(Seq("/usr/local/bin/docker", "exec", "-i", <your docker container name>, "bash"))

こうすることでdocker execを実行することもできる