Does no one use serial ports any more?

Just askin'...

As I may have mentioned earlier, I'm having to deal with a cluster of UARTs under Linux.

I'd previously set the Baud rate, data bits, and the rest of the usual stuff, using termios.

Thing is: now I gotta do modem control.  This involves tty_ioctl.  All straightforward, right?  This is old stuff?

TTY_IOCTL(4)        Linux Programmer's Manual        TTY_IOCTL(4)

NAME
tty_ioctl - ioctls for terminals and serial lines

SYNOPSIS
#include <termios.h>

int ioctl(int fd, int cmd, ...);

. . .

Modem control
    TIOCMGET int *argp
    get the status of modem bits.

    TIOCMSET const int *argp
    set the status of modem bits.

    TIOCMBIC const int *argp
    clear the indicated modem bits.

    TIOCMBIS const int *argp
    set the indicated modem bits.

    Bits used by these four ioctls:

    TIOCM_LE DSR (data set ready/line enable)
    TIOCM_DTR DTR (data terminal ready)
    TIOCM_RTS RTS (request to send)
    TIOCM_ST Secondary TXD (transmit)
    TIOCM_SR Secondary RXD (receive)
    TIOCM_CTS CTS (clear to send)
    TIOCM_CAR DCD (data carrier detect)
    TIOCM_CD see TIOCM_CAR
    TIOCM_RNG RNG (ring)
    TIOCM_RI see TIOCM_RNG
    TIOCM_DSR DSR (data set ready)

Except... <termios.h> doesn't define those constants.  They're defined in <asm-generic/ioctls.h> and <asm-generic/termios.h>., and maybe in some other places, possibly valgrind-related and having machine-specific header names.  But!  The asm-generic version of termios has some sort of incompatible definition that now causes a segfault when I try to use the modern termios functions that worked before.

So I guess I gotta do some digging.  Maybe the answer is out there on the 'Net, or maybe I need to find the source code for, e.g., GtkTerm and see how it's handled there.

Update: The actual requirements appear to be

#include <sys/ioctl.h>
#include <termios.h>

At least, the program compiles and doesn't bomb instantly.  Now I need to see if it's actually working.