--- exp_chan.c.FCS      Thu Jun  3 20:31:46 2004
+++ exp_chan.c  Fri Jun  4 00:05:03 2004
@@ -109,6 +109,7 @@
     ExpState *esPtr = (ExpState *) instanceData;
     int bytesRead;                     /* How many bytes were actually
                                          * read from the input device? */
+struct pollfd fds[1];

     *errorCodePtr = 0;

@@ -118,6 +119,16 @@
      * possible, if the channel is in blocking mode. If the channel is
      * nonblocking, the read will never block.
      */
+fds[0].fd = esPtr->fdin;
+fds[0].events = POLLIN | POLLERR | POLLHUP | POLLNVAL;
+bytesRead = poll(fds, 1, 0);
+if (bytesRead <= 0) {
+       *errorCodePtr = EWOULDBLOCK;
+       return(-1);
+} else if (fds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
+       *errorCodePtr = EBADF;
+       return(-1);
+}

     bytesRead = read(esPtr->fdin, buf, (size_t) toRead);
     /*printf("ExpInputProc: read(%d,,) = %d\r\n",esPtr->fdin,bytesRead);*/