termios, ioctl problem

From: Carole MacDonald (elora_c_at_yahoo.com)
Date: 10/21/03

  • Next message: Julián Albo: "Re: termios, ioctl problem" 
    Date: 21 Oct 2003 10:33:30 -0700

    I have a C++ program that communicates with a device on a serial port
    using /dev/ttyS0. When my program checks for data with ioctl() and
    then do a read(), certain byte values are being dropped: 0x11 (start)
    and 0x13 (stop). I can send these out from my program just fine, I
    just can't read them in. I've looked at the termios structure and I'm
    sure I'm setting a flag improperly, but I can't figure it out. Here's
    what the stty -a output looks like:

    speed 9600 baud; rows 0; columns 0; line = 0;
    intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
    eol2 = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase =
    ^W;
    lnext = ^V; flush = ^O; min = 1; time = 0;
    -parenb -parodd cs8 hupcl -cstopb cread clocal -crtscts
    -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl
    ixon -ixoff
    -iuclc -ixany -imaxbel
    -opost olcuc ocrnl onlcr onocr onlret ofill ofdel nl1 cr3 tab3 bs1 vt1
    ff1
    -isig -icanon iexten -echo -echoe echok echonl noflsh xcase tostop
    echoprt
    -echoctl echoke

    and the code I'm using to set the settings on the port:
    //set the options for the Port
    fcntl(m_fd,F_SETFL,0);
    tcgetattr(m_fd,&settings);
    settings.c_lflag = ~(ICANON | ECHO | ECHOE | ISIG | ECHOCTL);
    settings.c_oflag &= ~OPOST;
    tcsetattr(m_fd,TCSANOW,&settings);
    fcntl(m_fd,F_SETFL,FNDELAY);

    If anyone can help me figure out the proper flags, I'd really
    appreciate it.

    Thanks,
    Carole

  • Next message: Julián Albo: "Re: termios, ioctl problem"

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