Scala example source code file (ProcessIO.scala)

This example Scala source code file (ProcessIO.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

boolean, inputstream, outputstream, processio, unit

The ProcessIO.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala
package sys
package process

import processInternal._

/** This class is used to control the I/O of every
  * [[scala.sys.process.Process]]. The functions used to create it will be
  * called with the process streams once it has been started. It might not be
  * necessary to use `ProcessIO` directly --
  * [[scala.sys.process.ProcessBuilder]] can return the process output to the
  * caller, or use a [[scala.sys.process.ProcessLogger]] which avoids direct
  * interaction with a stream. One can even use the factories at `BasicIO` to
  * create a `ProcessIO`, or use its helper methods when creating one's own
  * `ProcessIO`.
  *
  * When creating a `ProcessIO`, it is important to ''close all streams'' when
  * finished, since the JVM might use system resources to capture the process
  * input and output, and will not release them unless the streams are
  * explicitly closed.
  *
  * `ProcessBuilder` will call `writeInput`, `processOutput` and `processError`
  * in separate threads, and if daemonizeThreads is true, they will all be
  * marked as daemon threads.
  *
  * @param writeInput Function that will be called with the `OutputStream` to
  *                   which all input to the process must be written. This will
  *                   be called in a newly spawned thread.
  * @param processOutput Function that will be called with the `InputStream`
  *                      from which all normal output of the process must be
  *                      read from. This will be called in a newly spawned
  *                      thread.
  * @param processError Function that will be called with the `InputStream` from
  *                     which all error output of the process must be read from.
  *                     This will be called in a newly spawned thread.
  * @param daemonizeThreads Indicates whether the newly spawned threads that
  *                         will run `processOutput`, `processError` and
  *                         `writeInput` should be marked as daemon threads.
  * @note Failure to close the passed streams may result in resource leakage.
  */
final class ProcessIO(
  val writeInput: OutputStream => Unit,
  val processOutput: InputStream => Unit,
  val processError: InputStream => Unit,
  val daemonizeThreads: Boolean
) {
  def this(in: OutputStream => Unit, out: InputStream => Unit, err: InputStream => Unit) = this(in, out, err, false)

  /** Creates a new `ProcessIO` with a different handler for the process input. */
  def withInput(write: OutputStream => Unit): ProcessIO   = new ProcessIO(write, processOutput, processError, daemonizeThreads)

  /** Creates a new `ProcessIO` with a different handler for the normal output. */
  def withOutput(process: InputStream => Unit): ProcessIO = new ProcessIO(writeInput, process, processError, daemonizeThreads)

  /** Creates a new `ProcessIO` with a different handler for the error output. */
  def withError(process: InputStream => Unit): ProcessIO  = new ProcessIO(writeInput, processOutput, process, daemonizeThreads)

  /** Creates a new `ProcessIO`, with `daemonizeThreads` true. */
  def daemonized(): ProcessIO = new ProcessIO(writeInput, processOutput, processError, true)
}