I'm on a mac using Scala, and I want to create a Python interpreter as a subprocess that my program interacts with. I've been using Process with a ProcessIO, but python insists on running in non-interactive mode. So it only does anything after I close down its input and kill the process. Is there a way to force it to run in interactive mode, so that I can keep the Python process alive and interact with it? This sample code (which I'm pasting into a Scala repl) shows the problem:
import scala.sys.process._
import scala.io._
import java.io._
import scala.concurrent._
val inputStream = new SyncVar[OutputStream];
val process = Process("python").run(pio)
val pio = new ProcessIO(
(stdin: OutputStream) => {
inputStream.put(stdin)
},
(stdout: InputStream) => {
while (true) {
if (stdout.available > 0){
Source.fromInputStream(stdout).getLines.foreach(println)
}
}
},
stderr => Source.fromInputStream(stderr).getLines.foreach(println),
daemonizeThreads=true
)
def write(s: String): Unit = {
inputStream.get.write((s + "\n").getBytes)
inputStream.get.flush()
}
def close(): Unit = {
inputStream.get.close
}
write("import sys")
write("try: print 'ps1:', sys.ps1")
write("except: print 'no ps1'")
close // it's only here that output prints to the screen
