code: String getProcErrorOutput(Process proc) throws IOException {
          StringBuffer output = new StringBuffer();
  
          InputStream procIn = proc.getInputStream();
          int read;
          // Dump the data printed by the process
          do {
              byte[] buffer = new byte[BUFFER_SIZE];
              read = procIn.read(buffer);
              String s = new String(buffer);
              output.append(s);
          } while (read == BUFFER_SIZE);
  
          return output.toString();
      }
docs: Grabs the error message generated by executing the process.
  
  @param proc
  @throws IOException