> IMHO - keep using the open/read/write functions.  They do give you
> better control with less buffering.  (but very slightly less portable)

        Hmm, ok. Just in case this is my port opening routine (it's hardcoded for
the moment, I actually got this code from a website):

int open_port(void)
{
        int fd; /* File descriptor for the port */
        fd = open("/dev/ttyS1", O_RDONLY | O_NOCTTY | O_NDELAY);
        if (fd == -1)
        {
                /*
                * Could not open the port.
                */

                perror("open_port: Unable to open /dev/ttyS1 - ");
        }
        else
                fcntl(fd, F_SETFL, 0);

        return (fd);
}

> Are you "reading" something, but the read function is returning an error
> because there is nothing to read??  Check the return value of read().
> It should be the number of bytes gotten.

        I do check the return value and have the program set to error out if the
value returned is either 0 or -1:

returned_bytes = read (fd, &char_buf, 1);
if (returned_bytes == 0 || returned_bytes == -1)
{
        printf ("Error: Read of port failed! Aborting...\n");
        exit (1);
}

> If the file descriptor is set
> up for non-blocking reads and there is nothing there it will return a -1
> with errno set to EAGAIN.  Of course once you get misplaced in where the
> software thinks it is in the stream of data things get real hairy real
> quick.
>
> Dan

        According to the docs I have the fcntl up above sets it for blocking (which
is what I want, I want the program to sleep until something is received.

        Thanks for the help. TTYL

----------------------------------
Herbert's PIC Stuff:
http://repatch.dyndns.org:8383/pic_stuff/

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads