xref: /minix/external/bsd/nvi/dist/cl/cl_screen.c (revision 84d9c625)
1 /*	$NetBSD: cl_screen.c,v 1.3 2013/11/25 22:43:46 christos Exp $ */
2 /*-
3  * Copyright (c) 1993, 1994
4  *	The Regents of the University of California.  All rights reserved.
5  * Copyright (c) 1993, 1994, 1995, 1996
6  *	Keith Bostic.  All rights reserved.
7  *
8  * See the LICENSE file for redistribution information.
9  */
10 
11 #include "config.h"
12 
13 #ifndef lint
14 static const char sccsid[] = "Id: cl_screen.c,v 10.56 2002/05/03 19:59:44 skimo Exp  (Berkeley) Date: 2002/05/03 19:59:44 ";
15 #endif /* not lint */
16 
17 #include <sys/types.h>
18 #include <sys/queue.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 #include <termios.h>
27 #include <unistd.h>
28 
29 #include "../common/common.h"
30 #include "cl.h"
31 
32 static int	cl_ex_end __P((GS *));
33 static int	cl_ex_init __P((SCR *));
34 static void	cl_freecap __P((CL_PRIVATE *));
35 static int	cl_vi_end __P((GS *));
36 static int	cl_vi_init __P((SCR *));
37 static int	cl_putenv __P((SCR *, const char *, const char *, u_long));
38 
39 /*
40  * cl_screen --
41  *	Switch screen types.
42  *
43  * PUBLIC: int cl_screen __P((SCR *, u_int32_t));
44  */
45 int
46 cl_screen(SCR *sp, u_int32_t flags)
47 {
48 	CL_PRIVATE *clp;
49 	WINDOW *win;
50 	GS *gp;
51 
52 	gp = sp->gp;
53 	clp = CLP(sp);
54 	win = CLSP(sp) ? CLSP(sp) : stdscr;
55 
56 	/* See if the current information is incorrect. */
57 	if (F_ISSET(gp, G_SRESTART)) {
58 		if (CLSP(sp)) {
59 		    delwin(CLSP(sp));
60 		    sp->cl_private = NULL;
61 		}
62 		if (cl_quit(gp))
63 			return (1);
64 		F_CLR(gp, G_SRESTART);
65 	}
66 
67 	/* See if we're already in the right mode. */
68 	if ((LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX)) ||
69 	    (LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI)))
70 		return (0);
71 
72 	/*
73 	 * Fake leaving ex mode.
74 	 *
75 	 * We don't actually exit ex or vi mode unless forced (e.g. by a window
76 	 * size change).  This is because many curses implementations can't be
77 	 * called twice in a single program.  Plus, it's faster.  If the editor
78 	 * "leaves" vi to enter ex, when it exits ex we'll just fall back into
79 	 * vi.
80 	 */
81 	if (F_ISSET(sp, SC_SCR_EX))
82 		F_CLR(sp, SC_SCR_EX);
83 
84 	/*
85 	 * Fake leaving vi mode.
86 	 *
87 	 * Clear out the rest of the screen if we're in the middle of a split
88 	 * screen.  Move to the last line in the current screen -- this makes
89 	 * terminal scrolling happen naturally.  Note: *don't* move past the
90 	 * end of the screen, as there are ex commands (e.g., :read ! cat file)
91 	 * that don't want to.  Don't clear the info line, its contents may be
92 	 * valid, e.g. :file|append.
93 	 */
94 	if (F_ISSET(sp, SC_SCR_VI)) {
95 		F_CLR(sp, SC_SCR_VI);
96 
97 		if (TAILQ_NEXT(sp, q) != NULL) {
98 			(void)wmove(win, RLNO(sp, sp->rows), 0);
99 			wclrtobot(win);
100 		}
101 		(void)wmove(win, RLNO(sp, sp->rows) - 1, 0);
102 		wrefresh(win);
103 	}
104 
105 	/* Enter the requested mode. */
106 	if (LF_ISSET(SC_EX)) {
107 		if (cl_ex_init(sp))
108 			return (1);
109 		F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);
110 
111 		/*
112 		 * If doing an ex screen for ex mode, move to the last line
113 		 * on the screen.
114 		 */
115 		if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
116 			tputs(tgoto(clp->cup,
117 			    0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
118 	} else {
119 		if (cl_vi_init(sp))
120 			return (1);
121 		F_CLR(clp, CL_IN_EX);
122 		F_SET(clp, CL_SCR_VI_INIT);
123 	}
124 	return (0);
125 }
126 
127 /*
128  * cl_quit --
129  *	Shutdown the screens.
130  *
131  * PUBLIC: int cl_quit __P((GS *));
132  */
133 int
134 cl_quit(GS *gp)
135 {
136 	CL_PRIVATE *clp;
137 	int rval;
138 
139 	rval = 0;
140 	clp = GCLP(gp);
141 
142 	/*
143 	 * If we weren't really running, ignore it.  This happens if the
144 	 * screen changes size before we've called curses.
145 	 */
146 	if (!F_ISSET(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT))
147 		return (0);
148 
149 	/* Clean up the terminal mappings. */
150 	if (cl_term_end(gp))
151 		rval = 1;
152 
153 	/* Really leave vi mode. */
154 	if (F_ISSET(clp, CL_STDIN_TTY) &&
155 	    F_ISSET(clp, CL_SCR_VI_INIT) && cl_vi_end(gp))
156 		rval = 1;
157 
158 	/* Really leave ex mode. */
159 	if (F_ISSET(clp, CL_STDIN_TTY) &&
160 	    F_ISSET(clp, CL_SCR_EX_INIT) && cl_ex_end(gp))
161 		rval = 1;
162 
163 	/*
164 	 * If we were running ex when we quit, or we're using an implementation
165 	 * of curses where endwin() doesn't get this right, restore the original
166 	 * terminal modes.
167 	 *
168 	 * XXX
169 	 * We always do this because it's too hard to figure out what curses
170 	 * implementations get it wrong.  It may discard type-ahead characters
171 	 * from the tty queue.
172 	 */
173 	(void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig);
174 
175 	F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
176 	return (rval);
177 }
178 
179 /*
180  * cl_vi_init --
181  *	Initialize the curses vi screen.
182  */
183 static int
184 cl_vi_init(SCR *sp)
185 {
186 	CL_PRIVATE *clp;
187 	char *o_cols, *o_lines, *o_term;
188 	const char *ttype;
189 
190 	clp = CLP(sp);
191 
192 	/* If already initialized, just set the terminal modes. */
193 	if (F_ISSET(clp, CL_SCR_VI_INIT))
194 		goto fast;
195 
196 	/* Curses vi always reads from (and writes to) a terminal. */
197 	if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) {
198 		msgq(sp, M_ERR,
199 		    "016|Vi's standard input and output must be a terminal");
200 		return (1);
201 	}
202 
203 	/* We'll need a terminal type. */
204 	if (opts_empty(sp, O_TERM, 0))
205 		return (1);
206 	ttype = O_STR(sp, O_TERM);
207 
208 	/*
209 	 * XXX
210 	 * Changing the row/column and terminal values is done by putting them
211 	 * into the environment, which is then read by curses.  What this loses
212 	 * in ugliness, it makes up for in stupidity.  We can't simply put the
213 	 * values into the environment ourselves, because in the presence of a
214 	 * kernel mechanism for returning the window size, entering values into
215 	 * the environment will screw up future screen resizing events, e.g. if
216 	 * the user enters a :shell command and then resizes their window.  So,
217 	 * if they weren't already in the environment, we make sure to delete
218 	 * them immediately after setting them.
219 	 *
220 	 * XXX
221 	 * Putting the TERM variable into the environment is necessary, even
222 	 * though we're using newterm() here.  We may be using initscr() as
223 	 * the underlying function.
224 	 */
225 	o_term = getenv("TERM");
226 	cl_putenv(sp, "TERM", ttype, 0);
227 	o_lines = getenv("LINES");
228 	cl_putenv(sp, "LINES", NULL, (u_long)O_VAL(sp, O_LINES));
229 	o_cols = getenv("COLUMNS");
230 	cl_putenv(sp, "COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS));
231 
232 	/*
233 	 * We don't care about the SCREEN reference returned by newterm, we
234 	 * never have more than one SCREEN at a time.
235 	 *
236 	 * XXX
237 	 * The SunOS initscr() can't be called twice.  Don't even think about
238 	 * using it.  It fails in subtle ways (e.g. select(2) on fileno(stdin)
239 	 * stops working).  (The SVID notes that applications should only call
240 	 * initscr() once.)
241 	 *
242 	 * XXX
243 	 * The HP/UX newterm doesn't support the NULL first argument, so we
244 	 * have to specify the terminal type.
245 	 */
246 	errno = 0;
247 	if (newterm(__UNCONST(ttype), stdout, stdin) == NULL) {
248 		if (errno)
249 			msgq(sp, M_SYSERR, "%s", ttype);
250 		else
251 			msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
252 		return (1);
253 	}
254 
255 	if (o_term == NULL)
256 		cl_unsetenv(sp, "TERM");
257 	if (o_lines == NULL)
258 		cl_unsetenv(sp, "LINES");
259 	if (o_cols == NULL)
260 		cl_unsetenv(sp, "COLUMNS");
261 
262 	/*
263 	 * XXX
264 	 * Someone got let out alone without adult supervision -- the SunOS
265 	 * newterm resets the signal handlers.  There's a race, but it's not
266 	 * worth closing.
267 	 */
268 	(void)sig_init(sp->gp, sp);
269 
270 	/*
271 	 * We use raw mode.  What we want is 8-bit clean, however, signals
272 	 * and flow control should continue to work.  Admittedly, it sounds
273 	 * like cbreak, but it isn't.  Using cbreak() can get you additional
274 	 * things like IEXTEN, which turns on flags like DISCARD and LNEXT.
275 	 *
276 	 * !!!
277 	 * If raw isn't turning off echo and newlines, something's wrong.
278 	 * However, it shouldn't hurt.
279 	 */
280 	noecho();			/* No character echo. */
281 	nonl();				/* No CR/NL translation. */
282 	raw();				/* 8-bit clean. */
283 	idlok(stdscr, 1);		/* Use hardware insert/delete line. */
284 
285 	/* Put the cursor keys into application mode. */
286 	(void)keypad(stdscr, TRUE);
287 
288 	/*
289 	 * XXX
290 	 * The screen TI sequence just got sent.  See the comment in
291 	 * cl_funcs.c:cl_attr().
292 	 */
293 	clp->ti_te = TI_SENT;
294 
295 	/*
296 	 * XXX
297 	 * Historic implementations of curses handled SIGTSTP signals
298 	 * in one of three ways.  They either:
299 	 *
300 	 *	1: Set their own handler, regardless.
301 	 *	2: Did not set a handler if a handler was already installed.
302 	 *	3: Set their own handler, but then called any previously set
303 	 *	   handler after completing their own cleanup.
304 	 *
305 	 * We don't try and figure out which behavior is in place, we force
306 	 * it to SIG_DFL after initializing the curses interface, which means
307 	 * that curses isn't going to take the signal.  Since curses isn't
308 	 * reentrant (i.e., the whole curses SIGTSTP interface is a fantasy),
309 	 * we're doing The Right Thing.
310 	 */
311 	(void)signal(SIGTSTP, SIG_DFL);
312 
313 	/*
314 	 * If flow control was on, turn it back on.  Turn signals on.  ISIG
315 	 * turns on VINTR, VQUIT, VDSUSP and VSUSP.   The main curses code
316 	 * already installed a handler for VINTR.  We're going to disable the
317 	 * other three.
318 	 *
319 	 * XXX
320 	 * We want to use ^Y as a vi scrolling command.  If the user has the
321 	 * DSUSP character set to ^Y (common practice) clean it up.  As it's
322 	 * equally possible that the user has VDSUSP set to 'a', we disable
323 	 * it regardless.  It doesn't make much sense to suspend vi at read,
324 	 * so I don't think anyone will care.  Alternatively, we could look
325 	 * it up in the table of legal command characters and turn it off if
326 	 * it matches one.  VDSUSP wasn't in POSIX 1003.1-1990, so we test for
327 	 * it.
328 	 *
329 	 * XXX
330 	 * We don't check to see if the user had signals enabled originally.
331 	 * If they didn't, it's unclear what we're supposed to do here, but
332 	 * it's also pretty unlikely.
333 	 */
334 	if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) {
335 		msgq(sp, M_SYSERR, "tcgetattr");
336 		goto err;
337 	}
338 	if (clp->orig.c_iflag & IXON)
339 		clp->vi_enter.c_iflag |= IXON;
340 	if (clp->orig.c_iflag & IXOFF)
341 		clp->vi_enter.c_iflag |= IXOFF;
342 
343 	clp->vi_enter.c_lflag |= ISIG;
344 #ifdef VDSUSP
345 	clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE;
346 #endif
347 	clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE;
348 	clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE;
349 
350 	/*
351 	 * XXX
352 	 * OSF/1 doesn't turn off the <discard>, <literal-next> or <status>
353 	 * characters when curses switches into raw mode.  It should be OK
354 	 * to do it explicitly for everyone.
355 	 */
356 #ifdef VDISCARD
357 	clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE;
358 #endif
359 #ifdef VLNEXT
360 	clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE;
361 #endif
362 #ifdef VSTATUS
363 	clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE;
364 #endif
365 
366 	/* Initialize terminal based information. */
367 	if (cl_term_init(sp))
368 		goto err;
369 
370 fast:	/* Set the terminal modes. */
371 	if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) {
372 		if (errno == EINTR)
373 			goto fast;
374 		msgq(sp, M_SYSERR, "tcsetattr");
375 err:		(void)cl_vi_end(sp->gp);
376 		return (1);
377 	}
378 	return (0);
379 }
380 
381 /*
382  * cl_vi_end --
383  *	Shutdown the vi screen.
384  */
385 static int
386 cl_vi_end(GS *gp)
387 {
388 	CL_PRIVATE *clp;
389 
390 	clp = GCLP(gp);
391 
392 	/* Restore the cursor keys to normal mode. */
393 	(void)keypad(stdscr, FALSE);
394 
395 	/*
396 	 * If we were running vi when we quit, scroll the screen up a single
397 	 * line so we don't lose any information.
398 	 *
399 	 * Move to the bottom of the window (some endwin implementations don't
400 	 * do this for you).
401 	 */
402 	if (!F_ISSET(clp, CL_IN_EX)) {
403 		(void)move(0, 0);
404 		(void)deleteln();
405 		(void)move(LINES - 1, 0);
406 		(void)refresh();
407 	}
408 
409 	cl_freecap(clp);
410 
411 	/* End curses window. */
412 	(void)endwin();
413 
414 	/*
415 	 * XXX
416 	 * The screen TE sequence just got sent.  See the comment in
417 	 * cl_funcs.c:cl_attr().
418 	 */
419 	clp->ti_te = TE_SENT;
420 
421 	return (0);
422 }
423 
424 /*
425  * cl_ex_init --
426  *	Initialize the ex screen.
427  */
428 static int
429 cl_ex_init(SCR *sp)
430 {
431 	CL_PRIVATE *clp;
432 
433 	clp = CLP(sp);
434 
435 	/* If already initialized, just set the terminal modes. */
436 	if (F_ISSET(clp, CL_SCR_EX_INIT))
437 		goto fast;
438 
439 	/* If not reading from a file, we're done. */
440 	if (!F_ISSET(clp, CL_STDIN_TTY))
441 		return (0);
442 
443 	/* Get the ex termcap/terminfo strings. */
444 	(void)cl_getcap(sp, "cup", &clp->cup);
445 	(void)cl_getcap(sp, "smso", &clp->smso);
446 	(void)cl_getcap(sp, "rmso", &clp->rmso);
447 	(void)cl_getcap(sp, "el", &clp->el);
448 	(void)cl_getcap(sp, "cuu1", &clp->cuu1);
449 
450 	/* Enter_standout_mode and exit_standout_mode are paired. */
451 	if (clp->smso == NULL || clp->rmso == NULL) {
452 		if (clp->smso != NULL) {
453 			free(clp->smso);
454 			clp->smso = NULL;
455 		}
456 		if (clp->rmso != NULL) {
457 			free(clp->rmso);
458 			clp->rmso = NULL;
459 		}
460 	}
461 
462 	/*
463 	 * Turn on canonical mode, with normal input and output processing.
464 	 * Start with the original terminal settings as the user probably
465 	 * had them (including any local extensions) set correctly for the
466 	 * current terminal.
467 	 *
468 	 * !!!
469 	 * We can't get everything that we need portably; for example, ONLCR,
470 	 * mapping <newline> to <carriage-return> on output isn't required
471 	 * by POSIX 1003.1b-1993.  If this turns out to be a problem, then
472 	 * we'll either have to play some games on the mapping, or we'll have
473 	 * to make all ex printf's output \r\n instead of \n.
474 	 */
475 	clp->ex_enter = clp->orig;
476 	clp->ex_enter.c_lflag  |= ECHO | ECHOE | ECHOK | ICANON | IEXTEN | ISIG;
477 #ifdef ECHOCTL
478 	clp->ex_enter.c_lflag |= ECHOCTL;
479 #endif
480 #ifdef ECHOKE
481 	clp->ex_enter.c_lflag |= ECHOKE;
482 #endif
483 	clp->ex_enter.c_iflag |= ICRNL;
484 	clp->ex_enter.c_oflag |= OPOST;
485 #ifdef ONLCR
486 	clp->ex_enter.c_oflag |= ONLCR;
487 #endif
488 
489 fast:	if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) {
490 		if (errno == EINTR)
491 			goto fast;
492 		msgq(sp, M_SYSERR, "tcsetattr");
493 		return (1);
494 	}
495 	return (0);
496 }
497 
498 /*
499  * cl_ex_end --
500  *	Shutdown the ex screen.
501  */
502 static int
503 cl_ex_end(GS *gp)
504 {
505 	CL_PRIVATE *clp;
506 
507 	clp = GCLP(gp);
508 
509 	cl_freecap(clp);
510 
511 	return (0);
512 }
513 
514 /*
515  * cl_getcap --
516  *	Retrieve termcap/terminfo strings.
517  *
518  * PUBLIC: int cl_getcap __P((SCR *, const char *, char **));
519  */
520 int
521 cl_getcap(SCR *sp, const char *name, char **elementp)
522 {
523 	size_t len;
524 	char *t;
525 
526 	if ((t = tigetstr(name)) != NULL &&
527 	    t != (char *)-1 && (len = strlen(t)) != 0) {
528 		MALLOC_RET(sp, *elementp, char *, len + 1);
529 		memmove(*elementp, t, len + 1);
530 	}
531 	return (0);
532 }
533 
534 /*
535  * cl_freecap --
536  *	Free any allocated termcap/terminfo strings.
537  */
538 static void
539 cl_freecap(CL_PRIVATE *clp)
540 {
541 	if (clp->el != NULL) {
542 		free(clp->el);
543 		clp->el = NULL;
544 	}
545 	if (clp->cup != NULL) {
546 		free(clp->cup);
547 		clp->cup = NULL;
548 	}
549 	if (clp->cuu1 != NULL) {
550 		free(clp->cuu1);
551 		clp->cuu1 = NULL;
552 	}
553 	if (clp->rmso != NULL) {
554 		free(clp->rmso);
555 		clp->rmso = NULL;
556 	}
557 	if (clp->smso != NULL) {
558 		free(clp->smso);
559 		clp->smso = NULL;
560 	}
561 }
562 
563 /*
564  * cl_putenv --
565  *	Put a value into the environment.
566  */
567 static int
568 cl_putenv(SCR *sp, const char *name, const char *str, u_long value)
569 {
570 	char buf[40];
571 
572 	if (str == NULL) {
573 		(void)snprintf(buf, sizeof(buf), "%lu", value);
574 		return (cl_setenv(sp, name, buf));
575 	} else
576 		return (cl_setenv(sp, name, str));
577 }
578