Echo.java

package edu.smith.cs.csc262.coopsh.apps;
import edu.smith.cs.csc262.coopsh.ShellEnvironment;
import edu.smith.cs.csc262.coopsh.Task;

/**
 * This is a full implementation of Echo.
 * @author jfoley
 *
 */
public class Echo extends Task {

	/**
	 * Store the lines present in the user input.
	 */
	final String[] lines;
	/**
	 * Store the current index into the list for printing.
	 */
	int i = 0;
	
	/**
	 * Construct an Echo Task.
	 * @param env - the shell environment.
	 * @param args - the arguments to echo.
	 */
	public Echo(ShellEnvironment env, String[] args) {
		super(env, args);
		StringBuilder sb = new StringBuilder();
		for(int i=0; i<args.length; i++) {
			if (i > 0) sb.append(",");
			sb.append(args[i]);
		}
		this.lines = sb.toString().split("\n");
	}

	/**
	 * Update is like the body of a loop.
	 */
	@Override
	protected void update() {
		if (i < this.lines.length) {
			this.println(this.lines[i]);
			i++;
		} else {
			this.closeOutput();
			this.exit(0);
		}
	}
}