// ExecBug
//
// This program demonstrates two bugs with the error stream of an
// exec'd Process.
//
// What the program tries to do is exec a subprocess that writes something
// to stderr; read that text from the subprocess's error stream and echo it
// to System.err; and display the return value of the subprocess.
//
// What happens instead, when run using Solaris JDK 1.0.2:
//  - The first buffer read from the subprocess's error stream is "err = 1!".
//    This comes from src/solaris/java/green_threads/src/process_md.c,
//    java_lang_UNIXProcess_fork().
//  - The second buffer is ok, and contains the first part of the subprocess's
//    error message.
//  - The third buffer comes back from read() with a length of -2, causing
//    an ArrayIndexOutOfBoundsException.
//
// Sample run:
//     % java ExecBug
//     len=9
//     err = 1!
//     len=20
//     cat: cannot open /felen=-2
//     java.lang.ArrayIndexOutOfBoundsException
// 	    at java.io.BufferedOutputStream.write(BufferedOutputStream.java)
// 	    at java.io.PrintStream.write(PrintStream.java)
// 	    at ExecBug.main(ExecBug.java:37)
//
// This bug is fixed in JDK 1.1.
//
// Jef Poskanzer 17jul96

package Bugs;

import java.io.*;
import java.util.*;

public class ExecBug
    {
    public static void main( String[] args )
        {
	Runtime runtime = Runtime.getRuntime();
	Process process1 = null;
	int r = 1234;

	try
	    {
	    String[] cmd = { "/bin/cat", "/feepyfoo" };
	    process1 = runtime.exec( cmd );
	    }
	catch ( IOException e )
	    {
	    System.err.println( "exec: " + e );
	    System.exit( 1 );
	    }

	try
	    {
	    InputStream e = process1.getErrorStream();
	    byte[] buf = new byte[20];
	    int len;
	    boolean eEof = false;
	    while ( ! eEof )
		{
		len = e.read( buf );
		if ( len == -1 )
		    eEof = true;
		else if ( len != 0 )
		    {
		    System.err.println( "len=" + len );
		    System.err.write( buf, 0, len );
		    }
		}
	    e.close();
	    }
	catch ( IOException e )
	    {
	    System.err.println( "read: " + e );
	    System.exit( 1 );
	    }

	try
	    {
	    r = process1.waitFor();
	    }
	catch ( InterruptedException e )
	    {
	    System.err.println( "waitFor: " + e );
	    System.exit( 1 );
	    }
	
	System.out.println( "returned " + r );
	}

    }