Volume 7A: XView Programming Manual

Using ttysw_output() shows that the text is simply output to the dummy terminal emu-

lator described by ttysw. ttysw_input() is useful for sending data as input to a pro-

gram running in the TTY subwindow. For example, a window-based front end for a text edi-

tor could be written where all the common functions such as Save and Next Page can be pro-

grammed into panel buttons. Selecting one of those panel buttons would cause a constant

string to be sent to the application to be processed as input. The write filename function in vi

could have a button that uses ttysw_input() to send the string (w!\n) to the TTY

subwindow containing the program.

9.3 Monitoring the Program in the TTY Subwindow

When you use the TTY_ARGV attribute to pass the name of a program to run to the TTY

subwindow, the program runs as a forked child process. If the attribute:

TTY_QUIT_ON_CHILD_DEATH

is set to TRUE, then the application exits when the forked program exits. But, by default, this

attribute is set to FALSE. You can use TTY_PID to monitor the state of the child process run-

ning in the TTY window via the Notifier using notify_set_wait3_func(). The cli-

ent’s wait3() function gets called when the state of the process in the TTY subwindow

changes:*

#include <sys/wait.h>

static Notify_value my_wait3();

...

ttysw = xv_create(base_frame, TTY,

TTY_ARGV, my_argv,

NULL);

child_pid = (int)xv_get(ttysw, TTY_PID);

notify_set_wait3_func(ttysw, my_wait3, child_pid);

...

The wait3() function can then do something useful, such as destroying the TTY window or

starting up another process. The code fragment below detects when any of the TTY subwin-

dow’s child processes has died.

static Notify_value

my_wait3(ttysw, pid, status, rusage)

Tty ttysw;

int pid;

union wait *status;

struct rusage *rusage;

{

int child_pid;

notify_next_wait3_func(ttysw, pid, status, rusage);

if (!(WIFSTOPPED(*status))) {

/* rerun the program */

xv_set(ttysw, TTY_ARGV, my_argv, NULL);

*This includes when the program stops in addition to when it exits.

246 XView Programming Manual

child_pid = (int)xv_get(ttysw, TTY_PID);

notify_set_wait3_func(ttysw, my_wait3, child_pid);

}

return NOTIFY_DONE;

}

You can set TTY_PID as well as get it, but if you set it, you are responsible for setting:

notify_set_wait3_func()

to catch the child’s death. You are also responsible for directing the standard input and stan-

dard output of the child to the pseudo-TTY.

9.4 Talking Directly to the TTY Subwindow

Setting TTY_ARGV to TTY_ARGV_DO_NOT_FORK tells the system not to fork a child in the TTY

subwindow. In combination with TTY_TTY_FD, this allows the tool to use standard I/O rou-

tines to read and write to the TTY subwindow by getting the file descriptor of the pseudo-

TTY associated with the TTY subwindow. You can then use this to read and write to the

pseudo-TTY using standard UNIX I/O routines.

Example 9-3 uses a TTY subwindow to create a pseudo terminal in which curses routines can

be used. Five panel items are displayed. Along with the usual Quit button to exit the pro-

gram, a Print button displays the text in the text panel item at the coordinates input in the X

and Y numeric text items.

Example 9-3. The ttycurses.c program

/*

* ttycurses.c -- An application that uses a tty subwindow that

* emulates a tty so well, you can use curses(3x) routines in it.

* This program does not handle resizes -- resizing the base frame

* produces unpredictable results. To handle resizing properly,

* the application should install a resize event handler and

* call endwin() followed by initscr() to reinitialize curses

* to reflect the size of the window.

*

* cc ttycurses.c -lxview -lcurses -ltermlib

*/

#include <curses.h>

#undef WINDOW /* defined by curses.h -- needs to be undefined */

#include <xview/xview.h>

#include <xview/panel.h>

#include <xview/textsw.h>

#include <xview/tty.h>

/* panel items contain the x,y info for outputting text to the ttysw */

Panel_item x, y, text;

main(argc,argv)

int argc;

char *argv[ ];

{

Frame frame;

TTY Subwindows

TTY Subwindows 247

Example 9-3. The ttycurses.c program (continued)

Panel panel;

Tty ttysw;

char buf[16];

void output(), exit();

xv_init(XV_INIT_ARGC_PTR_ARGV, &argc, argv, NULL);

frame = xv_create(XV_NULL, FRAME,

FRAME_LABEL, argv[0],

FRAME_SHOW_FOOTER, TRUE,

NULL);

panel = (Frame)xv_create(frame, PANEL, NULL);

(void) xv_create(panel, PANEL_BUTTON,

PANEL_LABEL_STRING, "Quit",

PANEL_NOTIFY_PROC, exit,

NULL);

(void) xv_create(panel, PANEL_BUTTON,

PANEL_LABEL_STRING, "Print",

PANEL_NOTIFY_PROC, output,

NULL);

x = (Panel_item)xv_create(panel, PANEL_NUMERIC_TEXT,

PANEL_LABEL_STRING, "X:",

PANEL_VALUE_DISPLAY_LENGTH, 3,

NULL);

y = (Panel_item)xv_create(panel, PANEL_NUMERIC_TEXT,

PANEL_LABEL_STRING, "Y:",

PANEL_VALUE_DISPLAY_LENGTH, 3,

NULL);

text = (Panel_item)xv_create(panel, PANEL_TEXT,

PANEL_LABEL_STRING, "Text:",

PANEL_VALUE_DISPLAY_LENGTH, 10,

PANEL_VALUE, "X",

NULL);

window_fit(panel);

ttysw = (Tty)xv_create(frame, TTY,

WIN_BELOW, panel,

WIN_X, 0,

TTY_ARGV, TTY_ARGV_DO_NOT_FORK,

NULL);

window_fit(frame);

dup2((int)xv_get(ttysw, TTY_TTY_FD), 0); /* dup2 closes 0 first */

dup2((int)xv_get(ttysw, TTY_TTY_FD), 1); /* dup2 closes 1 first */

/* initscr() initializes the curses package and determines

* characteristics about the window as if it were a terminal.

* The curses specific variables, LINES and COLS are now set

* to the row and column sizes of the window.

*/

initscr();

xv_set(x, PANEL_MAX_VALUE, COLS-1, NULL);

xv_set(y, PANEL_MAX_VALUE, LINES-1, NULL);

sprintf(buf, "LINES: %d", LINES–1);

248 XView Programming Manual

Example 9-3. The ttycurses.c program (continued)

xv_set(frame, FRAME_LEFT_FOOTER, buf, NULL);

sprintf(buf, "COLS: %d", COLS–1);

xv_set(frame, FRAME_RIGHT_FOOTER, buf, NULL);

xv_main_loop(frame);

}

/*

* callback routine for the <print> panel button. Get the coordinates

* and the text to print on the tty subwindow and use curses library

* routines to render the text.

*/

void

output()

{

int X = (int)xv_get(x, PANEL_VALUE);

int Y = (int)xv_get(y, PANEL_VALUE);

char *Text = (char *)xv_get(text, PANEL_VALUE);

mvaddstr(Y, X, Text);

refresh();

}

9.5 TTY Subwindow Function Key Escape Sequences

XView provides a default .ttyswrc file for the shelltool which provides the SunView

escape key sequences for the following keys: L3, F1-F12, R1-R7, R9, R11, R13, and R15 (for

more details see $OPENWINHOME/lib/.ttyswrc). To override the default file, place any

.ttyswrc file in your $HOME directory. To avoid using any .ttyswrc file, place the follow-

ing line in your .Xdefaults file:

term.useAlternateTtyswrc: False

In addition, you will need to remove any .ttyswrc files from your $HOME directory. To spec-

ify a different alternate file than the one in $OPENWINHOME/lib/.ttyswrc, place the follow-

ing into your .Xdefaults file:

term.alternateTtyswrc:

filename

where filename is the path and name of the file to use. For example:

term.alternateTtyswrc: /usr/lib/ttyswrc

When using a Sun Type 4 keyboard with an X11 server other than OpenWindows 3.0, escape

key sequences cannot be produced for keys F11 and F12 due to a limitation in the standard

X11 keysym definition file. The base keysym file distributed by the X Consortium limits the

number of unique function keys to a maximum of 35 (for more details see

$OPENWINHOME/include/X11/keysym.h). The Sun Type 4 keyboard has 37 keysyms. For

OpenWindows, there are two extra keysyms Sun_F36 and Sun_F37 which allow XView and

other X-based programs to perform unique actions on the F11 and F12 keys (for more details

see $OPENWINHOME/include/X11/Sunkeysym.h).

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TTY Subwindows 249

9.6 TTY Package Summary

The TTYSW procedures are shown in Table 9-1. Table 9-2 lists the TTYSW attributes. This

information is described fully in the XView Reference Manual.

Table 9-1. TTY Subwindow Procedures

ttysw_input()

ttysw_output()

Table 9-2. TTY Subwindow Attributes

TTY_ARGV

TTY_ARGV_DO_NOT_FORK

TTY_CONSOLE

TTY_PAGE_MODE

TTY_PID

TTY_QUIT_ON_CHILD_DEATH

TTY_TTY_FD

WIN_FONT

WIN_SET_FOCUS

250 XView Programming Manual