import com.darwinsys.util.*;

import java.io.*;

/**
 * ExecDemo shows how to execute an external program (in this case
 * the UNIX directory lister /bin/ls) and read its output.
 */
public class ExecDemoLs {
	/** The program to run */
	public static final String PROGRAM = "ls";

	public static void main(String argv[]) throws IOException { 

		Process p; 		// Process tracks one external native process
		BufferedReader is;	// reader for output of process
		String line;
		
		p = Runtime.getRuntime().exec(PROGRAM);

		Debug.println("exec", "In Main after exec");

		// getInputStream gives an Input stream connected to 
		// the process p's standard output (and vice versa). We use
		// that to construct a BufferedReader so we can readLine() it.
		is = new BufferedReader(new InputStreamReader(p.getInputStream()));

		while ((line = is.readLine()) != null)
			System.out.println(line);
		
		Debug.println("exec", "In Main after EOF");

		return;
	}
}