xref: /freebsd/contrib/nvi/cl/cl_screen.c (revision ab0b9f6b3073e6c4d1dfbf07444d7db67a189a96)
1 /*-
2  * Copyright (c) 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "$Id: cl_screen.c,v 10.56 2002/05/03 19:59:44 skimo Exp $";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #include <sys/time.h>
19 
20 #include <bitstring.h>
21 #include <errno.h>
22 #include <signal.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #ifdef HAVE_TERM_H
27 #include <term.h>
28 #endif
29 #include <termios.h>
30 #include <unistd.h>
31 
32 #include "../common/common.h"
33 #include "cl.h"
34 
35 static int	cl_ex_end __P((GS *));
36 static int	cl_ex_init __P((SCR *));
37 static void	cl_freecap __P((CL_PRIVATE *));
38 static int	cl_vi_end __P((GS *));
39 static int	cl_vi_init __P((SCR *));
40 static int	cl_putenv __P((char *, char *, u_long));
41 
42 /*
43  * cl_screen --
44  *	Switch screen types.
45  *
46  * PUBLIC: int cl_screen __P((SCR *, u_int32_t));
47  */
48 int
49 cl_screen(SCR *sp, u_int32_t flags)
50 {
51 	CL_PRIVATE *clp;
52 	WINDOW *win;
53 	GS *gp;
54 
55 	gp = sp->gp;
56 	clp = CLP(sp);
57 	win = CLSP(sp) ? CLSP(sp) : stdscr;
58 
59 	/* See if the current information is incorrect. */
60 	if (F_ISSET(gp, G_SRESTART)) {
61 		if (CLSP(sp)) {
62 		    delwin(CLSP(sp));
63 		    sp->cl_private = NULL;
64 		}
65 		if (cl_quit(gp))
66 			return (1);
67 		F_CLR(gp, G_SRESTART);
68 	}
69 
70 	/* See if we're already in the right mode. */
71 	if ((LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX)) ||
72 	    (LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI)))
73 		return (0);
74 
75 	/*
76 	 * Fake leaving ex mode.
77 	 *
78 	 * We don't actually exit ex or vi mode unless forced (e.g. by a window
79 	 * size change).  This is because many curses implementations can't be
80 	 * called twice in a single program.  Plus, it's faster.  If the editor
81 	 * "leaves" vi to enter ex, when it exits ex we'll just fall back into
82 	 * vi.
83 	 */
84 	if (F_ISSET(sp, SC_SCR_EX))
85 		F_CLR(sp, SC_SCR_EX);
86 
87 	/*
88 	 * Fake leaving vi mode.
89 	 *
90 	 * Clear out the rest of the screen if we're in the middle of a split
91 	 * screen.  Move to the last line in the current screen -- this makes
92 	 * terminal scrolling happen naturally.  Note: *don't* move past the
93 	 * end of the screen, as there are ex commands (e.g., :read ! cat file)
94 	 * that don't want to.  Don't clear the info line, its contents may be
95 	 * valid, e.g. :file|append.
96 	 */
97 	if (F_ISSET(sp, SC_SCR_VI)) {
98 		F_CLR(sp, SC_SCR_VI);
99 
100 		if (TAILQ_NEXT(sp, q) != NULL) {
101 			(void)wmove(win, RLNO(sp, sp->rows), 0);
102 			wclrtobot(win);
103 		}
104 		(void)wmove(win, RLNO(sp, sp->rows) - 1, 0);
105 		wrefresh(win);
106 	}
107 
108 	/* Enter the requested mode. */
109 	if (LF_ISSET(SC_EX)) {
110 		if (cl_ex_init(sp))
111 			return (1);
112 		F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);
113 
114 		/*
115 		 * If doing an ex screen for ex mode, move to the last line
116 		 * on the screen.
117 		 */
118 		if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
119 			tputs(tgoto(clp->cup,
120 			    0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
121 	} else {
122 		if (cl_vi_init(sp))
123 			return (1);
124 		F_CLR(clp, CL_IN_EX);
125 		F_SET(clp, CL_SCR_VI_INIT);
126 	}
127 	return (0);
128 }
129 
130 /*
131  * cl_quit --
132  *	Shutdown the screens.
133  *
134  * PUBLIC: int cl_quit __P((GS *));
135  */
136 int
137 cl_quit(GS *gp)
138 {
139 	CL_PRIVATE *clp;
140 	int rval;
141 
142 	rval = 0;
143 	clp = GCLP(gp);
144 
145 	/*
146 	 * If we weren't really running, ignore it.  This happens if the
147 	 * screen changes size before we've called curses.
148 	 */
149 	if (!F_ISSET(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT))
150 		return (0);
151 
152 	/* Clean up the terminal mappings. */
153 	if (cl_term_end(gp))
154 		rval = 1;
155 
156 	/* Really leave vi mode. */
157 	if (F_ISSET(clp, CL_STDIN_TTY) &&
158 	    F_ISSET(clp, CL_SCR_VI_INIT) && cl_vi_end(gp))
159 		rval = 1;
160 
161 	/* Really leave ex mode. */
162 	if (F_ISSET(clp, CL_STDIN_TTY) &&
163 	    F_ISSET(clp, CL_SCR_EX_INIT) && cl_ex_end(gp))
164 		rval = 1;
165 
166 	/*
167 	 * If we were running ex when we quit, or we're using an implementation
168 	 * of curses where endwin() doesn't get this right, restore the original
169 	 * terminal modes.
170 	 *
171 	 * XXX
172 	 * We always do this because it's too hard to figure out what curses
173 	 * implementations get it wrong.  It may discard type-ahead characters
174 	 * from the tty queue.
175 	 */
176 	(void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig);
177 
178 	F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
179 	return (rval);
180 }
181 
182 /*
183  * cl_vi_init --
184  *	Initialize the curses vi screen.
185  */
186 static int
187 cl_vi_init(SCR *sp)
188 {
189 	CL_PRIVATE *clp;
190 	GS *gp;
191 	char *o_cols, *o_lines, *o_term, *ttype;
192 
193 	gp = sp->gp;
194 	clp = CLP(sp);
195 
196 	/* If already initialized, just set the terminal modes. */
197 	if (F_ISSET(clp, CL_SCR_VI_INIT))
198 		goto fast;
199 
200 	/* Curses vi always reads from (and writes to) a terminal. */
201 	if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) {
202 		msgq(sp, M_ERR,
203 		    "016|Vi's standard input and output must be a terminal");
204 		return (1);
205 	}
206 
207 	/* We'll need a terminal type. */
208 	if (opts_empty(sp, O_TERM, 0))
209 		return (1);
210 	ttype = O_STR(sp, O_TERM);
211 
212 	/*
213 	 * XXX
214 	 * Changing the row/column and terminal values is done by putting them
215 	 * into the environment, which is then read by curses.  What this loses
216 	 * in ugliness, it makes up for in stupidity.  We can't simply put the
217 	 * values into the environment ourselves, because in the presence of a
218 	 * kernel mechanism for returning the window size, entering values into
219 	 * the environment will screw up future screen resizing events, e.g. if
220 	 * the user enters a :shell command and then resizes their window.  So,
221 	 * if they weren't already in the environment, we make sure to delete
222 	 * them immediately after setting them.
223 	 *
224 	 * XXX
225 	 * Putting the TERM variable into the environment is necessary, even
226 	 * though we're using newterm() here.  We may be using initscr() as
227 	 * the underlying function.
228 	 */
229 	o_term = getenv("TERM");
230 	cl_putenv("TERM", ttype, 0);
231 	o_lines = getenv("LINES");
232 	cl_putenv("LINES", NULL, (u_long)O_VAL(sp, O_LINES));
233 	o_cols = getenv("COLUMNS");
234 	cl_putenv("COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS));
235 
236 	/*
237 	 * We don't care about the SCREEN reference returned by newterm, we
238 	 * never have more than one SCREEN at a time.
239 	 *
240 	 * XXX
241 	 * The SunOS initscr() can't be called twice.  Don't even think about
242 	 * using it.  It fails in subtle ways (e.g. select(2) on fileno(stdin)
243 	 * stops working).  (The SVID notes that applications should only call
244 	 * initscr() once.)
245 	 *
246 	 * XXX
247 	 * The HP/UX newterm doesn't support the NULL first argument, so we
248 	 * have to specify the terminal type.
249 	 */
250 	(void)del_curterm(cur_term);
251 	errno = 0;
252 	if (newterm(ttype, stdout, stdin) == NULL) {
253 		if (errno)
254 			msgq(sp, M_SYSERR, "%s", ttype);
255 		else
256 			msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
257 		return (1);
258 	}
259 
260 	if (o_term == NULL)
261 		unsetenv("TERM");
262 	if (o_lines == NULL)
263 		unsetenv("LINES");
264 	if (o_cols == NULL)
265 		unsetenv("COLUMNS");
266 
267 	/*
268 	 * XXX
269 	 * Someone got let out alone without adult supervision -- the SunOS
270 	 * newterm resets the signal handlers.  There's a race, but it's not
271 	 * worth closing.
272 	 */
273 	(void)sig_init(sp->gp, sp);
274 
275 	/*
276 	 * We use raw mode.  What we want is 8-bit clean, however, signals
277 	 * and flow control should continue to work.  Admittedly, it sounds
278 	 * like cbreak, but it isn't.  Using cbreak() can get you additional
279 	 * things like IEXTEN, which turns on flags like DISCARD and LNEXT.
280 	 *
281 	 * !!!
282 	 * If raw isn't turning off echo and newlines, something's wrong.
283 	 * However, it shouldn't hurt.
284 	 */
285 	noecho();			/* No character echo. */
286 	nonl();				/* No CR/NL translation. */
287 	raw();				/* 8-bit clean. */
288 	idlok(stdscr, 1);		/* Use hardware insert/delete line. */
289 
290 	/* Put the cursor keys into application mode. */
291 	(void)keypad(stdscr, TRUE);
292 
293 	/*
294 	 * XXX
295 	 * The screen TI sequence just got sent.  See the comment in
296 	 * cl_funcs.c:cl_attr().
297 	 */
298 	clp->ti_te = TI_SENT;
299 
300 	/*
301 	 * XXX
302 	 * Historic implementations of curses handled SIGTSTP signals
303 	 * in one of three ways.  They either:
304 	 *
305 	 *	1: Set their own handler, regardless.
306 	 *	2: Did not set a handler if a handler was already installed.
307 	 *	3: Set their own handler, but then called any previously set
308 	 *	   handler after completing their own cleanup.
309 	 *
310 	 * We don't try and figure out which behavior is in place, we force
311 	 * it to SIG_DFL after initializing the curses interface, which means
312 	 * that curses isn't going to take the signal.  Since curses isn't
313 	 * reentrant (i.e., the whole curses SIGTSTP interface is a fantasy),
314 	 * we're doing The Right Thing.
315 	 */
316 	(void)signal(SIGTSTP, SIG_DFL);
317 
318 	/*
319 	 * If flow control was on, turn it back on.  Turn signals on.  ISIG
320 	 * turns on VINTR, VQUIT, VDSUSP and VSUSP.   The main curses code
321 	 * already installed a handler for VINTR.  We're going to disable the
322 	 * other three.
323 	 *
324 	 * XXX
325 	 * We want to use ^Y as a vi scrolling command.  If the user has the
326 	 * DSUSP character set to ^Y (common practice) clean it up.  As it's
327 	 * equally possible that the user has VDSUSP set to 'a', we disable
328 	 * it regardless.  It doesn't make much sense to suspend vi at read,
329 	 * so I don't think anyone will care.  Alternatively, we could look
330 	 * it up in the table of legal command characters and turn it off if
331 	 * it matches one.  VDSUSP wasn't in POSIX 1003.1-1990, so we test for
332 	 * it.
333 	 *
334 	 * XXX
335 	 * We don't check to see if the user had signals enabled originally.
336 	 * If they didn't, it's unclear what we're supposed to do here, but
337 	 * it's also pretty unlikely.
338 	 */
339 	if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) {
340 		msgq(sp, M_SYSERR, "tcgetattr");
341 		goto err;
342 	}
343 	if (clp->orig.c_iflag & IXON)
344 		clp->vi_enter.c_iflag |= IXON;
345 	if (clp->orig.c_iflag & IXOFF)
346 		clp->vi_enter.c_iflag |= IXOFF;
347 
348 	clp->vi_enter.c_lflag |= ISIG;
349 #ifdef VDSUSP
350 	clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE;
351 #endif
352 	clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE;
353 	clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE;
354 
355 	/*
356 	 * XXX
357 	 * OSF/1 doesn't turn off the <discard>, <literal-next> or <status>
358 	 * characters when curses switches into raw mode.  It should be OK
359 	 * to do it explicitly for everyone.
360 	 */
361 #ifdef VDISCARD
362 	clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE;
363 #endif
364 #ifdef VLNEXT
365 	clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE;
366 #endif
367 #ifdef VSTATUS
368 	clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE;
369 #endif
370 
371 	/* Initialize terminal based information. */
372 	if (cl_term_init(sp))
373 		goto err;
374 
375 fast:	/* Set the terminal modes. */
376 	if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) {
377 		if (errno == EINTR)
378 			goto fast;
379 		msgq(sp, M_SYSERR, "tcsetattr");
380 err:		(void)cl_vi_end(sp->gp);
381 		return (1);
382 	}
383 	return (0);
384 }
385 
386 /*
387  * cl_vi_end --
388  *	Shutdown the vi screen.
389  */
390 static int
391 cl_vi_end(GS *gp)
392 {
393 	CL_PRIVATE *clp;
394 
395 	clp = GCLP(gp);
396 
397 	/* Restore the cursor keys to normal mode. */
398 	(void)keypad(stdscr, FALSE);
399 
400 	/*
401 	 * If we were running vi when we quit, scroll the screen up a single
402 	 * line so we don't lose any information.
403 	 *
404 	 * Move to the bottom of the window (some endwin implementations don't
405 	 * do this for you).
406 	 */
407 	if (!F_ISSET(clp, CL_IN_EX)) {
408 		(void)move(0, 0);
409 		(void)deleteln();
410 		(void)move(LINES - 1, 0);
411 		(void)refresh();
412 	}
413 
414 	cl_freecap(clp);
415 
416 	/* End curses window. */
417 	(void)endwin();
418 
419 	/*
420 	 * XXX
421 	 * The screen TE sequence just got sent.  See the comment in
422 	 * cl_funcs.c:cl_attr().
423 	 */
424 	clp->ti_te = TE_SENT;
425 
426 	return (0);
427 }
428 
429 /*
430  * cl_ex_init --
431  *	Initialize the ex screen.
432  */
433 static int
434 cl_ex_init(SCR *sp)
435 {
436 	CL_PRIVATE *clp;
437 
438 	clp = CLP(sp);
439 
440 	/* If already initialized, just set the terminal modes. */
441 	if (F_ISSET(clp, CL_SCR_EX_INIT))
442 		goto fast;
443 
444 	/* If not reading from a file, we're done. */
445 	if (!F_ISSET(clp, CL_STDIN_TTY))
446 		return (0);
447 
448 	/* Get the ex termcap/terminfo strings. */
449 	(void)cl_getcap(sp, "cup", &clp->cup);
450 	(void)cl_getcap(sp, "smso", &clp->smso);
451 	(void)cl_getcap(sp, "rmso", &clp->rmso);
452 	(void)cl_getcap(sp, "el", &clp->el);
453 	(void)cl_getcap(sp, "cuu1", &clp->cuu1);
454 
455 	/* Enter_standout_mode and exit_standout_mode are paired. */
456 	if (clp->smso == NULL || clp->rmso == NULL) {
457 		if (clp->smso != NULL) {
458 			free(clp->smso);
459 			clp->smso = NULL;
460 		}
461 		if (clp->rmso != NULL) {
462 			free(clp->rmso);
463 			clp->rmso = NULL;
464 		}
465 	}
466 
467 	/*
468 	 * Turn on canonical mode, with normal input and output processing.
469 	 * Start with the original terminal settings as the user probably
470 	 * had them (including any local extensions) set correctly for the
471 	 * current terminal.
472 	 *
473 	 * !!!
474 	 * We can't get everything that we need portably; for example, ONLCR,
475 	 * mapping <newline> to <carriage-return> on output isn't required
476 	 * by POSIX 1003.1b-1993.  If this turns out to be a problem, then
477 	 * we'll either have to play some games on the mapping, or we'll have
478 	 * to make all ex printf's output \r\n instead of \n.
479 	 */
480 	clp->ex_enter = clp->orig;
481 	clp->ex_enter.c_lflag  |= ECHO | ECHOE | ECHOK | ICANON | IEXTEN | ISIG;
482 #ifdef ECHOCTL
483 	clp->ex_enter.c_lflag |= ECHOCTL;
484 #endif
485 #ifdef ECHOKE
486 	clp->ex_enter.c_lflag |= ECHOKE;
487 #endif
488 	clp->ex_enter.c_iflag |= ICRNL;
489 	clp->ex_enter.c_oflag |= OPOST;
490 #ifdef ONLCR
491 	clp->ex_enter.c_oflag |= ONLCR;
492 #endif
493 
494 fast:	if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) {
495 		if (errno == EINTR)
496 			goto fast;
497 		msgq(sp, M_SYSERR, "tcsetattr");
498 		return (1);
499 	}
500 	return (0);
501 }
502 
503 /*
504  * cl_ex_end --
505  *	Shutdown the ex screen.
506  */
507 static int
508 cl_ex_end(GS *gp)
509 {
510 	CL_PRIVATE *clp;
511 
512 	clp = GCLP(gp);
513 
514 	cl_freecap(clp);
515 
516 	return (0);
517 }
518 
519 /*
520  * cl_getcap --
521  *	Retrieve termcap/terminfo strings.
522  *
523  * PUBLIC: int cl_getcap __P((SCR *, char *, char **));
524  */
525 int
526 cl_getcap(SCR *sp, char *name, char **elementp)
527 {
528 	size_t len;
529 	char *t;
530 
531 	if ((t = tigetstr(name)) != NULL &&
532 	    t != (char *)-1 && (len = strlen(t)) != 0) {
533 		MALLOC_RET(sp, *elementp, char *, len + 1);
534 		memmove(*elementp, t, len + 1);
535 	}
536 	return (0);
537 }
538 
539 /*
540  * cl_freecap --
541  *	Free any allocated termcap/terminfo strings.
542  */
543 static void
544 cl_freecap(CL_PRIVATE *clp)
545 {
546 	if (clp->el != NULL) {
547 		free(clp->el);
548 		clp->el = NULL;
549 	}
550 	if (clp->cup != NULL) {
551 		free(clp->cup);
552 		clp->cup = NULL;
553 	}
554 	if (clp->cuu1 != NULL) {
555 		free(clp->cuu1);
556 		clp->cuu1 = NULL;
557 	}
558 	if (clp->rmso != NULL) {
559 		free(clp->rmso);
560 		clp->rmso = NULL;
561 	}
562 	if (clp->smso != NULL) {
563 		free(clp->smso);
564 		clp->smso = NULL;
565 	}
566 	/* Required by libcursesw :) */
567 	if (clp->cw.bp1.c != NULL) {
568 		free(clp->cw.bp1.c);
569 		clp->cw.bp1.c = NULL;
570 		clp->cw.blen1 = 0;
571 	}
572 }
573 
574 /*
575  * cl_putenv --
576  *	Put a value into the environment.
577  */
578 static int
579 cl_putenv(char *name, char *str, u_long value)
580 {
581 	char buf[40];
582 
583 	if (str == NULL) {
584 		(void)snprintf(buf, sizeof(buf), "%lu", value);
585 		return (setenv(name, buf, 1));
586 	} else
587 		return (setenv(name, str, 1));
588 }
589