CommandLauncher.java

/*
  CommandLauncher.java

  (c) 2006-2009 IBM and others (from CDT)

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package ejs.base.launch;

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;

public class CommandLauncher {

	protected Process fProcess;
	protected boolean fShowCommand;
	protected String[] fCommandArgs;

	protected String fErrorMessage = ""; //$NON-NLS-1$

	private String lineSeparator;

	/**
	 * The number of milliseconds to pause between polling.
	 */
	protected static final long DELAY = 50L;

	/**
	 * Creates a new launcher Fills in stderr and stdout output to the given
	 * streams. Streams can be set to <code>null</code>, if output not
	 * required
	 */
	public CommandLauncher() {
		fProcess = null;
		fShowCommand = false;
		lineSeparator = System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.ICommandLauncher#showCommand(boolean)
	 */
	public void showCommand(boolean show) {
		fShowCommand = show;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.ICommandLauncher#getErrorMessage()
	 */
	public String getErrorMessage() {
		return fErrorMessage;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.ICommandLauncher#setErrorMessage(java.lang.String)
	 */
	public void setErrorMessage(String error) {
		fErrorMessage = error;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.ICommandLauncher#getCommandArgs()
	 */
	public String[] getCommandArgs() {
		return fCommandArgs;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.ICommandLauncher#getCommandLine()
	 */
	public String getCommandLine() {
		return getCommandLine(getCommandArgs());
	}

	/**
	 * Constructs a command array that will be passed to the process
	 */
	protected String[] constructCommandArray(String command, String[] commandArgs) {
		String[] args = new String[1 + commandArgs.length];
		args[0] = command;
		System.arraycopy(commandArgs, 0, args, 1, commandArgs.length);
		return args;
	}
	
	/**
	 * @since 5.1
	 * @see org.eclipse.cdt.core.ICommandLauncher#execute(IPath, String[], String[], IPath, IProgressMonitor)
	 */
	public Process execute(String commandPath, String[] args, String[] env, String changeToDirectory) throws IOException {
		try {
			// add platform specific arguments (shell invocation)
			fCommandArgs = constructCommandArray(commandPath, args);
			
			File file = null;
			
			if(changeToDirectory != null)
				file = new File(changeToDirectory);
			
			fProcess = Runtime.getRuntime().exec(fCommandArgs, env, file);
			fErrorMessage = ""; //$NON-NLS-1$
		} catch (IOException e) {
			setErrorMessage(e.getMessage());
			fProcess = null;
		}
		return fProcess;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.ICommandLauncher#waitAndRead(java.io.OutputStream, java.io.OutputStream)
	 */
	public int waitAndRead(OutputStream out, OutputStream err) {
		if (fShowCommand) {
			printCommandLine(out);
		}

		if (fProcess == null) {
			return -1;
		}

		ProcessClosure closure = new ProcessClosure(fProcess, out, err);
		closure.runBlocking(); // a blocking call
		return fProcess.exitValue();
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.ICommandLauncher#waitAndRead(java.io.OutputStream, java.io.OutputStream, org.eclipse.core.runtime.IProgressMonitor)
	 */
	/*
	public int waitAndRead(OutputStream output, OutputStream err, IProgressMonitor monitor) {
		if (fShowCommand) {
			printCommandLine(output);
		}

		if (fProcess == null) {
			return -1;
		}

		ProcessClosure closure = new ProcessClosure(fProcess, output, err);
		closure.runNonBlocking();
		while (!monitor.isCanceled() && closure.isAlive()) {
			try {
				Thread.sleep(DELAY);
			} catch (InterruptedException ie) {
				// ignore
			}
		}

		// Operation canceled by the user, terminate abnormally.
		if (monitor.isCanceled()) {
			closure.terminate();
			setErrorMessage("cancelled");
		}

		try {
			return fProcess.waitFor();
		} catch (InterruptedException e) {
			// ignore
			return -1;
		}
	}
	*/
	protected void printCommandLine(OutputStream os) {
		if (os != null) {
			String cmd = getCommandLine(getCommandArgs());
			try {
				os.write(cmd.getBytes());
				os.flush();
			} catch (IOException e) {
				// ignore;
			}
		}
	}

	protected String getCommandLine(String[] commandArgs) {
		StringBuffer buf = new StringBuffer();
		if (fCommandArgs != null) {
			for (String commandArg : commandArgs) {
				buf.append(commandArg);
				buf.append(' ');
			}
			buf.append(lineSeparator);
		}
		return buf.toString();
	}

}