Name: rlT66838 Date: 08/19/97


I submitted this bug a while back, and just received
a request to submit it again. The latest version
I have tested it on is 1.1.2, but I saw nothing to
indicate that it was fixed on 1.1.3.

When I use the getInputStream() method on a process, then attempt
to use the available() method on that inputStream, the value returned
is always 0. This only appears to occur under Solaris, because
I have successfully run the same code under Windows 95.
Code to reproduce the bug is included below:

Firstly, the Test class execs a TestChild, then gets the input and output
streams, and writes "Blak\n" to the output. It then attemps to read
from the input using the available() method to check for incoming data:


import java.lang.*;
import java.io.*;


class Test {

  private static Process bidders;
  private static InputStream bids;
  private static OutputStream yell;

  public static void main (String[] args) throws InterruptedException {
    loadChild();
    yellAll("Blak\n");
    /*while (true) {
      try {String blah = getProcString(bids);
           if (blah != "") {System.out.println(blah);}
           } catch (IOException e) {}
    }*/
    bidders.waitFor();
  }

  //Test () {}

  public static void yellAll(String message) {
    byte[] byteMessage = new byte[20];
    System.out.println("Writing message: "+message);
    message.getBytes(0, message.length(), byteMessage, 1);
    ByteArrayInputStream l = new ByteArrayInputStream(byteMessage);

    try { yell.write(byteMessage);
    yell.flush();
    //yell.close();
    } catch (IOException e) {
      System.err.println("Error writing to process.\nError code: " + e);
    }
  } //End yellAll method



  private static void loadChild() {

    // try {
    try {
      bidders = Runtime.getRuntime().exec("java TestChild");
      bids = bidders.getInputStream();
      yell = bidders.getOutputStream();
    } catch (IOException e) {
      System.err.print("Bad news, I couldn't read from the file.\n Error code: " + e + ".\n");
    }
  } // End of method loadChild.


  private static String getProcString(InputStream input) throws IOException {
    int length = input.available(); //Under Solaris, this always returns 0.
    if (length != 0) {
      byte[] data = new byte[length];
      try {
        int i = input.read(data);
      } catch (IOException e) {}
      ByteArrayInputStream transStream = new ByteArrayInputStream(data);
      String retval = "";
      while (retval.length() < length /*&& (!retval.endsWith(" "))*/) {
        retval += (char)transStream.read();
      }
      return (retval.trim());
    }
    else {
      //happy = false;
      return "";
    }
  }


}//End of Test class

**************************************************

The TestChild class should read input, and bounce any one line of
input back through System.out. I've tested this by instead writing
to a file, and it is receiving the data perfectly. It is also writing
back perfectly, because when I removed the (available != 0) condition,
the read() method in Test blocked for a while and then read the data.


import java.lang.*;
import java.io.*;


class TestChild {
  public static void main (String[] args) {
   try {
    InputStream input = System.in;
    byte[] blah = new byte[1000];
    try {
      int i = input.read(blah);
    } catch (IOException e) {}
    ByteArrayInputStream BAS = new ByteArrayInputStream(blah);
    String readstuff = "";
    while ((BAS.available() > 0) && !(readstuff.endsWith("\n"))) {
      readstuff += (char)BAS.read();
    }
    FileOutputStream out = new FileOutputStream("TestOut2.txt");
    byte[] eeep = new byte[readsuff.length()];
    readstuff.getBytes(0, readstuff.length(), eeep, 0);
    out.write(eeep);
   } catch (IOException e) {}

  }

}


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