xref: /freebsd/contrib/nvi/cl/cl_screen.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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 10.58 2015/04/08 02:12:11 zy 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(GS *);
36 static int	cl_ex_init(SCR *);
37 static void	cl_freecap(CL_PRIVATE *);
38 static int	cl_vi_end(GS *);
39 static int	cl_vi_init(SCR *);
40 static int	cl_putenv(char *, char *, u_long);
41 
42 /*
43  * cl_screen --
44  *	Switch screen types.
45  *
46  * PUBLIC: int cl_screen(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 ((!F_ISSET(sp, SC_SCR_EX | SC_SCR_VI) ||
62 		     resizeterm(O_VAL(sp, O_LINES), O_VAL(sp, O_COLUMNS))) &&
63 		    cl_quit(gp))
64 			return (1);
65 		F_CLR(gp, G_SRESTART);
66 	}
67 
68 	/* See if we're already in the right mode. */
69 	if ((LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX)) ||
70 	    (LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI)))
71 		return (0);
72 
73 	/*
74 	 * Fake leaving ex mode.
75 	 *
76 	 * We don't actually exit ex or vi mode unless forced (e.g. by a window
77 	 * size change).  This is because many curses implementations can't be
78 	 * called twice in a single program.  Plus, it's faster.  If the editor
79 	 * "leaves" vi to enter ex, when it exits ex we'll just fall back into
80 	 * vi.
81 	 */
82 	if (F_ISSET(sp, SC_SCR_EX))
83 		F_CLR(sp, SC_SCR_EX);
84 
85 	/*
86 	 * Fake leaving vi mode.
87 	 *
88 	 * Clear out the rest of the screen if we're in the middle of a split
89 	 * screen.  Move to the last line in the current screen -- this makes
90 	 * terminal scrolling happen naturally.  Note: *don't* move past the
91 	 * end of the screen, as there are ex commands (e.g., :read ! cat file)
92 	 * that don't want to.  Don't clear the info line, its contents may be
93 	 * valid, e.g. :file|append.
94 	 */
95 	if (F_ISSET(sp, SC_SCR_VI)) {
96 		F_CLR(sp, SC_SCR_VI);
97 
98 		if (TAILQ_NEXT(sp, q) != NULL) {
99 			(void)wmove(win, RLNO(sp, sp->rows), 0);
100 			wclrtobot(win);
101 		}
102 		(void)wmove(win, RLNO(sp, sp->rows) - 1, 0);
103 		wrefresh(win);
104 	}
105 
106 	/* Enter the requested mode. */
107 	if (LF_ISSET(SC_EX)) {
108 		if (cl_ex_init(sp))
109 			return (1);
110 		F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);
111 
112 		/*
113 		 * If doing an ex screen for ex mode, move to the last line
114 		 * on the screen.
115 		 */
116 		if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
117 			tputs(tgoto(clp->cup,
118 			    0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
119 	} else {
120 		if (cl_vi_init(sp))
121 			return (1);
122 		F_CLR(clp, CL_IN_EX);
123 		F_SET(clp, CL_SCR_VI_INIT);
124 	}
125 	return (0);
126 }
127 
128 /*
129  * cl_quit --
130  *	Shutdown the screens.
131  *
132  * PUBLIC: int cl_quit(GS *);
133  */
134 int
135 cl_quit(GS *gp)
136 {
137 	CL_PRIVATE *clp;
138 	int rval;
139 
140 	rval = 0;
141 	clp = GCLP(gp);
142 
143 	/*
144 	 * If we weren't really running, ignore it.  This happens if the
145 	 * screen changes size before we've called curses.
146 	 */
147 	if (!F_ISSET(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT))
148 		return (0);
149 
150 	/* Clean up the terminal mappings. */
151 	if (cl_term_end(gp))
152 		rval = 1;
153 
154 	/* Really leave vi mode. */
155 	if (F_ISSET(clp, CL_STDIN_TTY) &&
156 	    F_ISSET(clp, CL_SCR_VI_INIT) && cl_vi_end(gp))
157 		rval = 1;
158 
159 	/* Really leave ex mode. */
160 	if (F_ISSET(clp, CL_STDIN_TTY) &&
161 	    F_ISSET(clp, CL_SCR_EX_INIT) && cl_ex_end(gp))
162 		rval = 1;
163 
164 	/*
165 	 * If we were running ex when we quit, or we're using an implementation
166 	 * of curses where endwin() doesn't get this right, restore the original
167 	 * terminal modes.
168 	 *
169 	 * XXX
170 	 * We always do this because it's too hard to figure out what curses
171 	 * implementations get it wrong.  It may discard type-ahead characters
172 	 * from the tty queue.
173 	 */
174 	(void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig);
175 
176 	F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
177 	return (rval);
178 }
179 
180 /*
181  * cl_vi_init --
182  *	Initialize the curses vi screen.
183  */
184 static int
185 cl_vi_init(SCR *sp)
186 {
187 	CL_PRIVATE *clp;
188 	GS *gp;
189 	char *o_cols, *o_lines, *o_term, *ttype;
190 
191 	gp = sp->gp;
192 	clp = CLP(sp);
193 
194 	/* If already initialized, just set the terminal modes. */
195 	if (F_ISSET(clp, CL_SCR_VI_INIT))
196 		goto fast;
197 
198 	/* Curses vi always reads from (and writes to) a terminal. */
199 	if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) {
200 		msgq(sp, M_ERR,
201 		    "016|Vi's standard input and output must be a terminal");
202 		return (1);
203 	}
204 
205 	/* We'll need a terminal type. */
206 	if (opts_empty(sp, O_TERM, 0))
207 		return (1);
208 	ttype = O_STR(sp, O_TERM);
209 
210 	/*
211 	 * XXX
212 	 * Changing the row/column and terminal values is done by putting them
213 	 * into the environment, which is then read by curses.  What this loses
214 	 * in ugliness, it makes up for in stupidity.  We can't simply put the
215 	 * values into the environment ourselves, because in the presence of a
216 	 * kernel mechanism for returning the window size, entering values into
217 	 * the environment will screw up future screen resizing events, e.g. if
218 	 * the user enters a :shell command and then resizes their window.  So,
219 	 * if they weren't already in the environment, we make sure to delete
220 	 * them immediately after setting them.
221 	 *
222 	 * XXX
223 	 * Putting the TERM variable into the environment is necessary, even
224 	 * though we're using newterm() here.  We may be using initscr() as
225 	 * the underlying function.
226 	 */
227 	o_term = getenv("TERM");
228 	cl_putenv("TERM", ttype, 0);
229 	o_lines = getenv("LINES");
230 	cl_putenv("LINES", NULL, (u_long)O_VAL(sp, O_LINES));
231 	o_cols = getenv("COLUMNS");
232 	cl_putenv("COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS));
233 
234 	/*
235 	 * The terminal is aways initialized, either in `main`, or by a
236 	 * previous call to newterm(3X).
237 	 */
238 	(void)del_curterm(cur_term);
239 
240 	/*
241 	 * We never have more than one SCREEN at a time, so set_term(NULL) will
242 	 * give us the last SCREEN.
243 	 */
244 	errno = 0;
245 	if (newterm(ttype, stdout, stdin) == NULL) {
246 		if (errno)
247 			msgq(sp, M_SYSERR, "%s", ttype);
248 		else
249 			msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
250 		return (1);
251 	}
252 
253 	if (o_term == NULL)
254 		unsetenv("TERM");
255 	if (o_lines == NULL)
256 		unsetenv("LINES");
257 	if (o_cols == NULL)
258 		unsetenv("COLUMNS");
259 
260 	/*
261 	 * XXX
262 	 * Someone got let out alone without adult supervision -- the SunOS
263 	 * newterm resets the signal handlers.  There's a race, but it's not
264 	 * worth closing.
265 	 */
266 	(void)sig_init(sp->gp, sp);
267 
268 	/*
269 	 * We use raw mode.  What we want is 8-bit clean, however, signals
270 	 * and flow control should continue to work.  Admittedly, it sounds
271 	 * like cbreak, but it isn't.  Using cbreak() can get you additional
272 	 * things like IEXTEN, which turns on flags like DISCARD and LNEXT.
273 	 *
274 	 * !!!
275 	 * If raw isn't turning off echo and newlines, something's wrong.
276 	 * However, it shouldn't hurt.
277 	 */
278 	noecho();			/* No character echo. */
279 	nonl();				/* No CR/NL translation. */
280 	raw();				/* 8-bit clean. */
281 	idlok(stdscr, 1);		/* Use hardware insert/delete line. */
282 
283 	/* Put the cursor keys into application mode. */
284 	(void)keypad(stdscr, TRUE);
285 
286 	/*
287 	 * XXX
288 	 * The screen TI sequence just got sent.  See the comment in
289 	 * cl_funcs.c:cl_attr().
290 	 */
291 	clp->ti_te = TI_SENT;
292 
293 	/*
294 	 * XXX
295 	 * Historic implementations of curses handled SIGTSTP signals
296 	 * in one of three ways.  They either:
297 	 *
298 	 *	1: Set their own handler, regardless.
299 	 *	2: Did not set a handler if a handler was already installed.
300 	 *	3: Set their own handler, but then called any previously set
301 	 *	   handler after completing their own cleanup.
302 	 *
303 	 * We don't try and figure out which behavior is in place, we force
304 	 * it to SIG_DFL after initializing the curses interface, which means
305 	 * that curses isn't going to take the signal.  Since curses isn't
306 	 * reentrant (i.e., the whole curses SIGTSTP interface is a fantasy),
307 	 * we're doing The Right Thing.
308 	 */
309 	(void)signal(SIGTSTP, SIG_DFL);
310 
311 	/*
312 	 * If flow control was on, turn it back on.  Turn signals on.  ISIG
313 	 * turns on VINTR, VQUIT, VDSUSP and VSUSP.   The main curses code
314 	 * already installed a handler for VINTR.  We're going to disable the
315 	 * other three.
316 	 *
317 	 * XXX
318 	 * We want to use ^Y as a vi scrolling command.  If the user has the
319 	 * DSUSP character set to ^Y (common practice) clean it up.  As it's
320 	 * equally possible that the user has VDSUSP set to 'a', we disable
321 	 * it regardless.  It doesn't make much sense to suspend vi at read,
322 	 * so I don't think anyone will care.  Alternatively, we could look
323 	 * it up in the table of legal command characters and turn it off if
324 	 * it matches one.  VDSUSP wasn't in POSIX 1003.1-1990, so we test for
325 	 * it.
326 	 *
327 	 * XXX
328 	 * We don't check to see if the user had signals enabled originally.
329 	 * If they didn't, it's unclear what we're supposed to do here, but
330 	 * it's also pretty unlikely.
331 	 */
332 	if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) {
333 		msgq(sp, M_SYSERR, "tcgetattr");
334 		goto err;
335 	}
336 	if (clp->orig.c_iflag & IXON)
337 		clp->vi_enter.c_iflag |= IXON;
338 	if (clp->orig.c_iflag & IXOFF)
339 		clp->vi_enter.c_iflag |= IXOFF;
340 
341 	clp->vi_enter.c_lflag |= ISIG;
342 #ifdef VDSUSP
343 	clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE;
344 #endif
345 	clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE;
346 	clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE;
347 
348 	/*
349 	 * XXX
350 	 * OSF/1 doesn't turn off the <discard>, <literal-next> or <status>
351 	 * characters when curses switches into raw mode.  It should be OK
352 	 * to do it explicitly for everyone.
353 	 */
354 #ifdef VDISCARD
355 	clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE;
356 #endif
357 #ifdef VLNEXT
358 	clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE;
359 #endif
360 #ifdef VSTATUS
361 	clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE;
362 #endif
363 
364 	/* Initialize terminal based information. */
365 	if (cl_term_init(sp))
366 		goto err;
367 
368 fast:	/* Set the terminal modes. */
369 	if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) {
370 		if (errno == EINTR)
371 			goto fast;
372 		msgq(sp, M_SYSERR, "tcsetattr");
373 err:		(void)cl_vi_end(sp->gp);
374 		return (1);
375 	}
376 	return (0);
377 }
378 
379 /*
380  * cl_vi_end --
381  *	Shutdown the vi screen.
382  */
383 static int
384 cl_vi_end(GS *gp)
385 {
386 	CL_PRIVATE *clp;
387 
388 	clp = GCLP(gp);
389 
390 	/* Restore the cursor keys to normal mode. */
391 	(void)keypad(stdscr, FALSE);
392 
393 	/*
394 	 * If we were running vi when we quit, scroll the screen up a single
395 	 * line so we don't lose any information.
396 	 *
397 	 * Move to the bottom of the window (some endwin implementations don't
398 	 * do this for you).
399 	 */
400 	if (!F_ISSET(clp, CL_IN_EX)) {
401 		(void)move(0, 0);
402 		(void)deleteln();
403 		(void)move(LINES - 1, 0);
404 		(void)refresh();
405 	}
406 
407 	cl_freecap(clp);
408 
409 	/* End curses window. */
410 	(void)endwin();
411 
412 	/* Free the SCREEN created by newterm(3X). */
413 	delscreen(set_term(NULL));
414 
415 	/*
416 	 * XXX
417 	 * The screen TE sequence just got sent.  See the comment in
418 	 * cl_funcs.c:cl_attr().
419 	 */
420 	clp->ti_te = TE_SENT;
421 
422 	return (0);
423 }
424 
425 /*
426  * cl_ex_init --
427  *	Initialize the ex screen.
428  */
429 static int
430 cl_ex_init(SCR *sp)
431 {
432 	CL_PRIVATE *clp;
433 
434 	clp = CLP(sp);
435 
436 	/* If already initialized, just set the terminal modes. */
437 	if (F_ISSET(clp, CL_SCR_EX_INIT))
438 		goto fast;
439 
440 	/* If not reading from a file, we're done. */
441 	if (!F_ISSET(clp, CL_STDIN_TTY))
442 		return (0);
443 
444 	/* Get the ex termcap/terminfo strings. */
445 	(void)cl_getcap(sp, "cup", &clp->cup);
446 	(void)cl_getcap(sp, "smso", &clp->smso);
447 	(void)cl_getcap(sp, "rmso", &clp->rmso);
448 	(void)cl_getcap(sp, "el", &clp->el);
449 	(void)cl_getcap(sp, "cuu1", &clp->cuu1);
450 
451 	/* Enter_standout_mode and exit_standout_mode are paired. */
452 	if (clp->smso == NULL || clp->rmso == NULL) {
453 		if (clp->smso != NULL) {
454 			free(clp->smso);
455 			clp->smso = NULL;
456 		}
457 		if (clp->rmso != NULL) {
458 			free(clp->rmso);
459 			clp->rmso = NULL;
460 		}
461 	}
462 
463 	/*
464 	 * Turn on canonical mode, with normal input and output processing.
465 	 * Start with the original terminal settings as the user probably
466 	 * had them (including any local extensions) set correctly for the
467 	 * current terminal.
468 	 *
469 	 * !!!
470 	 * We can't get everything that we need portably; for example, ONLCR,
471 	 * mapping <newline> to <carriage-return> on output isn't required
472 	 * by POSIX 1003.1b-1993.  If this turns out to be a problem, then
473 	 * we'll either have to play some games on the mapping, or we'll have
474 	 * to make all ex printf's output \r\n instead of \n.
475 	 */
476 	clp->ex_enter = clp->orig;
477 	clp->ex_enter.c_lflag  |= ECHO | ECHOE | ECHOK | ICANON | IEXTEN | ISIG;
478 #ifdef ECHOCTL
479 	clp->ex_enter.c_lflag |= ECHOCTL;
480 #endif
481 #ifdef ECHOKE
482 	clp->ex_enter.c_lflag |= ECHOKE;
483 #endif
484 	clp->ex_enter.c_iflag |= ICRNL;
485 	clp->ex_enter.c_oflag |= OPOST;
486 #ifdef ONLCR
487 	clp->ex_enter.c_oflag |= ONLCR;
488 #endif
489 
490 fast:	if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) {
491 		if (errno == EINTR)
492 			goto fast;
493 		msgq(sp, M_SYSERR, "tcsetattr");
494 		return (1);
495 	}
496 	return (0);
497 }
498 
499 /*
500  * cl_ex_end --
501  *	Shutdown the ex screen.
502  */
503 static int
504 cl_ex_end(GS *gp)
505 {
506 	CL_PRIVATE *clp;
507 
508 	clp = GCLP(gp);
509 
510 	cl_freecap(clp);
511 
512 	return (0);
513 }
514 
515 /*
516  * cl_getcap --
517  *	Retrieve termcap/terminfo strings.
518  *
519  * PUBLIC: int cl_getcap(SCR *, char *, char **);
520  */
521 int
522 cl_getcap(SCR *sp, char *name, char **elementp)
523 {
524 	size_t len;
525 	char *t;
526 
527 	if ((t = tigetstr(name)) != NULL &&
528 	    t != (char *)-1 && (len = strlen(t)) != 0) {
529 		MALLOC_RET(sp, *elementp, char *, len + 1);
530 		memmove(*elementp, t, len + 1);
531 	}
532 	return (0);
533 }
534 
535 /*
536  * cl_freecap --
537  *	Free any allocated termcap/terminfo strings.
538  */
539 static void
540 cl_freecap(CL_PRIVATE *clp)
541 {
542 	if (clp->el != NULL) {
543 		free(clp->el);
544 		clp->el = NULL;
545 	}
546 	if (clp->cup != NULL) {
547 		free(clp->cup);
548 		clp->cup = NULL;
549 	}
550 	if (clp->cuu1 != NULL) {
551 		free(clp->cuu1);
552 		clp->cuu1 = NULL;
553 	}
554 	if (clp->rmso != NULL) {
555 		free(clp->rmso);
556 		clp->rmso = NULL;
557 	}
558 	if (clp->smso != NULL) {
559 		free(clp->smso);
560 		clp->smso = NULL;
561 	}
562 	/* Required by libcursesw :) */
563 	if (clp->cw.bp1.c != NULL) {
564 		free(clp->cw.bp1.c);
565 		clp->cw.bp1.c = NULL;
566 		clp->cw.blen1 = 0;
567 	}
568 }
569 
570 /*
571  * cl_putenv --
572  *	Put a value into the environment.
573  */
574 static int
575 cl_putenv(char *name, char *str, u_long value)
576 {
577 	char buf[40];
578 
579 	if (str == NULL) {
580 		(void)snprintf(buf, sizeof(buf), "%lu", value);
581 		return (setenv(name, buf, 1));
582 	} else
583 		return (setenv(name, str, 1));
584 }
585