package commands;

import java.io.*;

import kernel.*;

/**
 * Prints given input.
 * 
 * @author Tomáš Podskalský
 */
public class echo extends AbstractProcess {
  public void realization() throws AppException {
    PipedOutputStream output = (this.getOut() != null) ? (PipedOutputStream) this
        .getOut()
        : null;
    try {
      for (String arg : getArgs()) {
        String s = new String(arg + " ");
        output.write(s.getBytes());
      }
      String s = new String("\n");
      output.write(s.getBytes());
      output.flush();
    } catch (IOException ioe) {
      ioe.printStackTrace();
      throw new AppException(" I/O Error\n" + ioe.getMessage(), ioe);
    } catch (NullPointerException npe) {
      npe.printStackTrace();
      throw new AppException("Output is not specified\n" + npe.getMessage(),
          npe);
    } catch (Exception e) {
      e.printStackTrace();
      throw new AppException("Unknown error.\n" + e.getMessage(), e);
    }
  }

  /**
   * Provides help for users.
   * 
   */

  public String getHelp() {
    return "\n\nDescription:\nPrints given input.\n\nPoužití:\n"
        + "echo [arg1 [arg2 [...]]]\n\n" + "arg1, arg2, ...\tstrings to print.";
  }
}