Well.. if the while loop keeps me from receiving the signal, then I dont understand signals anymore.. ! ;-). Concerning select - as you say - it hangs the program waiting for input, meaning I cannot do anything else but just waiting in the meantime.

Otherwise, yes I have checked the HOWTO and allready knew it (I usually read the Serial Programing HOWTO at linuxdoc.org. Just for the record, actually I think there is a small flaw in its Asynchrounous Input example (here under is a small snipet from it):

 while (STOP==FALSE) {
    printf(".\n");usleep(100000);
    /* after receiving SIGIO, wait_flag = FALSE, input is available
       and can be read */
    if (wait_flag==FALSE) { 
      res = read(fd,buf,255);
      buf[res]=0;
      printf(":%s:%d\n", buf, res);
      if (res==1) STOP=TRUE; /* stop loop if only a CR was input */
      wait_flag = TRUE;      /* wait for new input */
    }
  }

[download]

Before this while loop a signal handler was installed, which will set wait_flag to FALSE if a signal arrives. With this code, when a signal arrives the buffer will be read, resetted, and printed out before setting wait_flag back to TRUE again. But what if some data comes to the port when it is printing out? The signal handler will set wait_flag to FALSE, and the loop will set it back to TRUE again afther testing for res.. I think I might just end up waiting (forever) for input that was allready there.. (?)

In reply to Re: Re: Re: Re: Handling I/O Signals by stephane
in thread Handling I/O Signals by stephane

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