HELP TERMIO                                 Mark Rubinstein  January 1986

Interface to the System V TERMIO ioctl calls.

    lib termio;

This file describes a library which provides procedures, structure
definitions and keyword constants for use with -sys_io_control-.  Calls
of -sys_io_control- may then have the same form as the "ioctl" calls
described in section termio(7) of the Unix Programmers manual.

See REF * SYSIO for full details of -sys_io_control-.

The primary calls of the Unix system V terminal io interface use a
structure defined in the Unix manual termio(7) as:

        #define     NCC 8
        struct termio {
            unsigned short  c_iflag;        /* input modes */
            unsigned short  c_oflag;        /* output modes */
            unsigned short  c_cflag;        /* control modes */
            unsigned short  c_lflag;        /* local modes */
            char            c_line;         /* line discipline */
            unsigned char   c_cc[NCC];      /* control characters */
        };

From POPLOG you can use the 'termio_struct' defined in the library as:

    recordclass global termio_struct
        termio_dummy1:full          /* dummy word */
        termio_iflag:16             /* input modes */
        termio_oflag:16             /* output modes */
        termio_cflag:16             /* control modes */
        termio_lflag:16             /* local modes */
        termio_line:8               /* line discipline */
            termio_vintr:8          /* interrupt */
            termio_vquit:8          /* quit */
            termio_verase:8         /* erase <DEL> */
            termio_vkill:8          /* kill (line) */
            termio_veof:8           /* end-of-file */
            termio_veol:8           /* end-of-line delimiter */
            termio_dummy2:8         /* reserved */
            termio_switch:8         /* switch, used for job control */
    ;

-sys_io_control- is used as follows (see REF * SYSIO for full details).

    sys_io_control(<device>, <request>, <struct:arg>) -> boolean;

Where the structure is a termio_struct as above and the request is an
integer.

The 'termio' library defines constants for 6 'ioctl' requests. These
are:

    TCGETA  Get the parameters associated with the terminal and store in
            the termio structure referenced by arg.

    TCSETA  Set the parameters associated with the terminal from the
            structure referenced by arg.  The change is immediate.

    TCSETAW Wait for the output to drain before setting the new
            parameters.  This form should be used when changing
            parameters that will affect output.

    TCSETAF Wait for the output to drain, then flush the input queue and
            set the new parameters.

    TCSBRK  Wait for the output to drain.  If arg is 0, then send a
            break (zero bits for 0.25 seconds).

    TCXONC  Start/stop control.  If arg is 0, suspend output; if 1,
            restart suspended output.

    TCFLSH  If arg is 0, flush the input queue; if 1, flush the output
            queue; if 2, flush both the input and output queues.

The 'termio' library also defines the masks for the input, output,
control and local mode flags.  For full details see LIB * TERMIO.

For example suppose you wish to make control-G the interrupt character
and disable start/stop output control for the device used by ved
(poprawdevin):

    uses termio;

    ;;; make a termio_struct
    vars tstruct = constermio_struct(0,0,0,0,0,0,0,0,0,0,0,0,0,0);

    ;;; get the parameters for poprawdevin
    unless sys_io_control(poprawdevin, TCGETA, tstruct) then
        mishap('SYS_IO_CONTROL error (using TCGETA)', []);
    endunless;

    ;;; make ^G interrupt character
    `\^G` -> termio_vintr(tstruct);

    ;;; mask out the IXON (enable start/stop output control) flag bits
    termio_iflag(tstruct) &&~~ IXON -> termio_iflag(tstruct);

    ;;; set the parameters for poprawdevin
    unless sys_io_control(poprawdevin, TCSETA, tstruct) then
        mishap('SYS_IO_CONTROL error (using TCSETA)', []);
    endunless;


See also HELP * IOCTL for definitions relating to the BSD 4.2 TTY
interface.


--- C.unix/help/termio
--- Copyright University of Sussex 1992. All rights reserved. ----------
