ptolemy.actor.lib.jjs.modules.shell

Class ShellHelper

java.lang.Object

ptolemy.actor.lib.jjs.modules.shell.ShellHelper

public class ShellHelper
extends java.lang.Object

A helper class for the shell accessor module. It provides functionality to invoke a command and control stdin and stdout. It forks off a process that executes the specified command. A reader thread listens to the process' output and forwards them via the EventEmitter subsystem ('message' event) to the shell.js module in Nashorn. A wait thread waits until the process exits and emits a 'close' event containing the process' exit value.

Since:

Ptolemy II 11.0

Version:

$Id$

Author:

Armin Wasicek

Pt.AcceptedRating:

Red (bilung)

Pt.ProposedRating:

Yellow (eal)

Method Summary

Modifier and Type	Method and Description
static ShellHelper	createShell(jdk.nashorn.api.scripting.ScriptObjectMirror scriptObjectMirror, java.lang.String command) Factory method to create a new shell.
void	start() Start the process and the reader thread.
void	wrapup() Kill the process and the reader thread.
void	write(java.lang.String input) Write to the stdin of the process.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

createShell

public static ShellHelper createShell(jdk.nashorn.api.scripting.ScriptObjectMirror scriptObjectMirror,
                                      java.lang.String command)

Factory method to create a new shell.

Parameters:

scriptObjectMirror - The JavaScript instance invoking the shell.

command - The command to be executed.

Returns:

a new shell.

write

public void write(java.lang.String input)
           throws java.io.IOException

Write to the stdin of the process.

Parameters:

input - The data to be sent to the process.

Throws:

java.io.IOException - If the string cannot be written.

start

public void start()

Start the process and the reader thread. Call this after initialization and all callbacks have been installed. TODO: get the exit value of the process.

wrapup

public void wrapup()
            throws java.io.IOException

Kill the process and the reader thread.

Throws:

java.io.IOException - Not thrown in this base class.