Fortuned's Reading and Writing


          /* and while it has stuff to write */
          while (!dead_pipe){
               int pfd = fileno(pipe_in);
               int wrc = 0;
               /* we read from it */
               memset (readbuf, 0, sizeof (readbuf));
               rc = read(pfd, readbuf, sizeof(readbuf));
               if (rc == -1){
                    if (errno == EINTR)
                         continue;
                    snprintf(errstring, sizeof(errstring), 
                             "read returned error '%s'", strerror(errno));
                    goto cleanup;
               }else if (rc == 0){
                    /* EOF is reached, hooray. */
                    break;
               }
               /* and write it to our caller */
               while (wrc < rc){
                    int bytes_written = 0; 
                    if ((bytes_written = write (fd, readbuf, strlen (readbuf))) == -1){
                         if ((errno == EINTR) || (errno == EAGAIN))
                              continue;
                         warn("failed to write to the fd, error '%s'", strerror(errno));
                         goto pipe_done;
                    }
                    wrc += bytes_written;
               }
          }




Fortuned's Main Loop

     /* this is the main loop */
     while(1){
  FILE* pipe_in;
  char readbuf[1024];
  fd_set wset;
  /* first of all, open the device file for writing */
  fd = open(device_file, OPEN_FLAGS, OPEN_COMMON);
  log ("succesfully opened!");
  if (fd == -1){
       snprintf(errstring, sizeof(errstring), 
"failed to open the fifo. error '%s'", strerror(errno));
       goto cleanup;
  }

  /* first of all, make sure we handle SIGPIPE gracefully */
  signal(SIGPIPE, sigpipehandler);
  
  /* we open a pipe with the fortune binary */
  if ((pipe_in = popen(FORTUNE_BINARY, "r")) == NULL){
       snprintf(errstring, sizeof(errstring), 
"could not popen(%s)", FORTUNE_BINARY);
       goto cleanup;
  }