How to get Java like PID in scala - scala

Question

In my Java program, i am using "this.PID" to get the current process PID.
I am looking for something similar in Scala - how to get same 6 char unique PID (as by java prgm).
looked through multiple post. Once such post suggest to use "MemoryManagementFactory".
However this returns #Hostname. Though, I am looking for a way to get similar 6 char JVM format PID.
Please suggest. Scala version: 2.11

Answer 1

Scala does not have a special API to get the process id. This is of course limited because of the JVM. Since Scala runs on the JVM, there is no platform independent API that will work no matter what architecture you run your program on. So most of what Scala can provide in this context are wrappers on top of what the Java API offers already in the context of processes.
For example, you could try scala.sys.process but as the documentation says:
The underlying basis for the whole package is Java's Process and
ProcessBuilder classes. While there's no need to use these Java
classes, they impose boundaries on what is possible. One cannot, for
instance, retrieve a process id for whatever is executing.
However, in Windows you can use the ManagementFactory.getRuntimeMXBean.getName method that will result in a string of the form[PID]#[MACHINE_NAME] and you can further process that to get only the PID.
Since JDK 10 you can also directly obtain the PID using ManagementFactory.getRuntimeMXBean.getPid.
But in both cases you will get the PID of the current running JVM, so if you need the PID of some other running program, I don't think that is possible.
Here is the equivalent Scala code:
object Program extends App {
import java.lang.management.ManagementFactory
val bean = ManagementFactory.getRuntimeMXBean
// Get name representing the running Java virtual machine.
// It returns something like [PID]#[MACHINE_NAME]. The value before
// the # symbol is the PID.
val jvmName = bean.getName
System.out.println("Name = " + jvmName)
// Extract the PID by splitting the string returned by the
// bean.getName() method.
var pid = jvmName.split("#")(0).toLong
System.out.println("PID = " + pid)
// Since JDK 10 you can get the process ID representing the running Java virtual machine.
pid = ManagementFactory.getRuntimeMXBean.getPid
System.out.println("PID = " + pid)
}
For me it outputs:
Name = 12412#VALHALLA
PID = 12412
PID = 12412
VALHALLA is the name of my host machine, while 12412 is the PID of the current JVM instance.