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

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	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.