/*
 * shutdown.java
 *
 * Implementation of the SHUTDOWN command.
 */
package commands;

import kernel.*;

/**
 * Terminates the system by terminating the root process.
 * 
 * @author Jan Horky
 */
public class shutdown extends AbstractProcess {
  /**
   * Realizes the SHUTDOWN command.
   * 
   * @throws AppException
   *             Exception caused by an error in the virtual machines manager.
   */
  public void realization() throws AppException {
    AbstractProcess rootProcess = getServices().getProcess(1);
    if (rootProcess != null)
      rootProcess.kill();
    else
      this.printError("shutdown: Can't find the root process\n");
  }

  /**
   * Provides full description of the command to be used in the MAN command.
   * 
   * @return Full description of the command including the syntax.
   */
  public String getHelp() {
    return "\n\nDescription:\nTerminates the system.\n\nUsage:\n"
        + "This command doesn't have any arguments ...";
  }
}