xref: /freebsd/contrib/nvi/cl/cl_screen.c (revision c6ec7d31830ab1c80edae95ad5e4b9dba10c47ac)
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  * $FreeBSD$
10  */
11 
12 #include "config.h"
13 
14 #ifndef lint
15 static const char sccsid[] = "@(#)cl_screen.c	10.49 (Berkeley) 9/24/96";
16 #endif /* not lint */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 
21 #include <bitstring.h>
22 #include <curses.h>
23 #include <errno.h>
24 #include <signal.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <term.h>
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(sp, flags)
50 	SCR *sp;
51 	u_int32_t flags;
52 {
53 	CL_PRIVATE *clp;
54 	GS *gp;
55 
56 	gp = sp->gp;
57 	clp = CLP(sp);
58 
59 	/* See if the current information is incorrect. */
60 	if (F_ISSET(gp, G_SRESTART)) {
61 		if (cl_quit(gp))
62 			return (1);
63 		F_CLR(gp, G_SRESTART);
64 	}
65 
66 	/* See if we're already in the right mode. */
67 	if (LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX) ||
68 	    LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI))
69 		return (0);
70 
71 	/*
72 	 * Fake leaving ex mode.
73 	 *
74 	 * We don't actually exit ex or vi mode unless forced (e.g. by a window
75 	 * size change).  This is because many curses implementations can't be
76 	 * called twice in a single program.  Plus, it's faster.  If the editor
77 	 * "leaves" vi to enter ex, when it exits ex we'll just fall back into
78 	 * vi.
79 	 */
80 	if (F_ISSET(sp, SC_SCR_EX))
81 		F_CLR(sp, SC_SCR_EX);
82 
83 	/*
84 	 * Fake leaving vi mode.
85 	 *
86 	 * Clear out the rest of the screen if we're in the middle of a split
87 	 * screen.  Move to the last line in the current screen -- this makes
88 	 * terminal scrolling happen naturally.  Note: *don't* move past the
89 	 * end of the screen, as there are ex commands (e.g., :read ! cat file)
90 	 * that don't want to.  Don't clear the info line, its contents may be
91 	 * valid, e.g. :file|append.
92 	 */
93 	if (F_ISSET(sp, SC_SCR_VI)) {
94 		F_CLR(sp, SC_SCR_VI);
95 
96 		if (sp->q.cqe_next != (void *)&gp->dq) {
97 			(void)move(RLNO(sp, sp->rows), 0);
98 			clrtobot();
99 		}
100 		(void)move(RLNO(sp, sp->rows) - 1, 0);
101 		refresh();
102 	}
103 
104 	/* Enter the requested mode. */
105 	if (LF_ISSET(SC_EX)) {
106 		if (cl_ex_init(sp))
107 			return (1);
108 		F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);
109 
110 		/*
111 		 * If doing an ex screen for ex mode, move to the last line
112 		 * on the screen.
113 		 */
114 		if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
115 			tputs(tgoto(clp->cup,
116 			    0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
117 	} else {
118 		if (cl_vi_init(sp))
119 			return (1);
120 		F_CLR(clp, CL_IN_EX);
121 		F_SET(clp, CL_SCR_VI_INIT);
122 	}
123 	return (0);
124 }
125 
126 /*
127  * cl_quit --
128  *	Shutdown the screens.
129  *
130  * PUBLIC: int cl_quit __P((GS *));
131  */
132 int
133 cl_quit(gp)
134 	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(sp)
185 	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 	 * We don't care about the SCREEN reference returned by newterm, we
236 	 * never have more than one SCREEN at a time.
237 	 *
238 	 * XXX
239 	 * The SunOS initscr() can't be called twice.  Don't even think about
240 	 * using it.  It fails in subtle ways (e.g. select(2) on fileno(stdin)
241 	 * stops working).  (The SVID notes that applications should only call
242 	 * initscr() once.)
243 	 *
244 	 * XXX
245 	 * The HP/UX newterm doesn't support the NULL first argument, so we
246 	 * have to specify the terminal type.
247 	 */
248 	errno = 0;
249 	if (newterm(ttype, stdout, stdin) == NULL) {
250 		if (errno)
251 			msgq(sp, M_SYSERR, "%s", ttype);
252 		else
253 			msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
254 		return (1);
255 	}
256 
257 	if (o_term == NULL)
258 		unsetenv("TERM");
259 	if (o_lines == NULL)
260 		unsetenv("LINES");
261 	if (o_cols == NULL)
262 		unsetenv("COLUMNS");
263 
264 	/*
265 	 * XXX
266 	 * Someone got let out alone without adult supervision -- the SunOS
267 	 * newterm resets the signal handlers.  There's a race, but it's not
268 	 * worth closing.
269 	 */
270 	(void)sig_init(sp->gp, sp);
271 
272 	/*
273 	 * We use raw mode.  What we want is 8-bit clean, however, signals
274 	 * and flow control should continue to work.  Admittedly, it sounds
275 	 * like cbreak, but it isn't.  Using cbreak() can get you additional
276 	 * things like IEXTEN, which turns on flags like DISCARD and LNEXT.
277 	 *
278 	 * !!!
279 	 * If raw isn't turning off echo and newlines, something's wrong.
280 	 * However, it shouldn't hurt.
281 	 */
282 	noecho();			/* No character echo. */
283 	nonl();				/* No CR/NL translation. */
284 	raw();				/* 8-bit clean. */
285 	idlok(stdscr, 1);		/* Use hardware insert/delete line. */
286 
287 	/* Put the cursor keys into application mode. */
288 	(void)keypad(stdscr, TRUE);
289 
290 	/*
291 	 * XXX
292 	 * The screen TI sequence just got sent.  See the comment in
293 	 * cl_funcs.c:cl_attr().
294 	 */
295 	clp->ti_te = TI_SENT;
296 
297 	/*
298 	 * XXX
299 	 * Historic implementations of curses handled SIGTSTP signals
300 	 * in one of three ways.  They either:
301 	 *
302 	 *	1: Set their own handler, regardless.
303 	 *	2: Did not set a handler if a handler was already installed.
304 	 *	3: Set their own handler, but then called any previously set
305 	 *	   handler after completing their own cleanup.
306 	 *
307 	 * We don't try and figure out which behavior is in place, we force
308 	 * it to SIG_DFL after initializing the curses interface, which means
309 	 * that curses isn't going to take the signal.  Since curses isn't
310 	 * reentrant (i.e., the whole curses SIGTSTP interface is a fantasy),
311 	 * we're doing The Right Thing.
312 	 */
313 	(void)signal(SIGTSTP, SIG_DFL);
314 
315 	/*
316 	 * If flow control was on, turn it back on.  Turn signals on.  ISIG
317 	 * turns on VINTR, VQUIT, VDSUSP and VSUSP.   The main curses code
318 	 * already installed a handler for VINTR.  We're going to disable the
319 	 * other three.
320 	 *
321 	 * XXX
322 	 * We want to use ^Y as a vi scrolling command.  If the user has the
323 	 * DSUSP character set to ^Y (common practice) clean it up.  As it's
324 	 * equally possible that the user has VDSUSP set to 'a', we disable
325 	 * it regardless.  It doesn't make much sense to suspend vi at read,
326 	 * so I don't think anyone will care.  Alternatively, we could look
327 	 * it up in the table of legal command characters and turn it off if
328 	 * it matches one.  VDSUSP wasn't in POSIX 1003.1-1990, so we test for
329 	 * it.
330 	 *
331 	 * XXX
332 	 * We don't check to see if the user had signals enabled originally.
333 	 * If they didn't, it's unclear what we're supposed to do here, but
334 	 * it's also pretty unlikely.
335 	 */
336 	if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) {
337 		msgq(sp, M_SYSERR, "tcgetattr");
338 		goto err;
339 	}
340 	if (clp->orig.c_iflag & IXON)
341 		clp->vi_enter.c_iflag |= IXON;
342 	if (clp->orig.c_iflag & IXOFF)
343 		clp->vi_enter.c_iflag |= IXOFF;
344 
345 	clp->vi_enter.c_lflag |= ISIG;
346 #ifdef VDSUSP
347 	clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE;
348 #endif
349 	clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE;
350 	clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE;
351 
352 	/*
353 	 * XXX
354 	 * OSF/1 doesn't turn off the <discard>, <literal-next> or <status>
355 	 * characters when curses switches into raw mode.  It should be OK
356 	 * to do it explicitly for everyone.
357 	 */
358 #ifdef VDISCARD
359 	clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE;
360 #endif
361 #ifdef VLNEXT
362 	clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE;
363 #endif
364 #ifdef VSTATUS
365 	clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE;
366 #endif
367 
368 	/* Initialize terminal based information. */
369 	if (cl_term_init(sp))
370 		goto err;
371 
372 fast:	/* Set the terminal modes. */
373 	if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) {
374 		if (errno == EINTR)
375 			goto fast;
376 		msgq(sp, M_SYSERR, "tcsetattr");
377 err:		(void)cl_vi_end(sp->gp);
378 		return (1);
379 	}
380 	return (0);
381 }
382 
383 /*
384  * cl_vi_end --
385  *	Shutdown the vi screen.
386  */
387 static int
388 cl_vi_end(gp)
389 	GS *gp;
390 {
391 	CL_PRIVATE *clp;
392 
393 	clp = GCLP(gp);
394 
395 	/* Restore the cursor keys to normal mode. */
396 	(void)keypad(stdscr, FALSE);
397 
398 	/*
399 	 * If we were running vi when we quit, scroll the screen up a single
400 	 * line so we don't lose any information.
401 	 *
402 	 * Move to the bottom of the window (some endwin implementations don't
403 	 * do this for you).
404 	 */
405 	if (!F_ISSET(clp, CL_IN_EX)) {
406 		(void)move(0, 0);
407 		(void)deleteln();
408 		(void)move(LINES - 1, 0);
409 		(void)refresh();
410 	}
411 
412 	cl_freecap(clp);
413 
414 	/* End curses window. */
415 	(void)endwin();
416 
417 	/*
418 	 * XXX
419 	 * The screen TE sequence just got sent.  See the comment in
420 	 * cl_funcs.c:cl_attr().
421 	 */
422 	clp->ti_te = TE_SENT;
423 
424 	return (0);
425 }
426 
427 /*
428  * cl_ex_init --
429  *	Initialize the ex screen.
430  */
431 static int
432 cl_ex_init(sp)
433 	SCR *sp;
434 {
435 	CL_PRIVATE *clp;
436 
437 	clp = CLP(sp);
438 
439 	/* If already initialized, just set the terminal modes. */
440 	if (F_ISSET(clp, CL_SCR_EX_INIT))
441 		goto fast;
442 
443 	/* If not reading from a file, we're done. */
444 	if (!F_ISSET(clp, CL_STDIN_TTY))
445 		return (0);
446 
447 	/* Get the ex termcap/terminfo strings. */
448 	(void)cl_getcap(sp, "cup", &clp->cup);
449 	(void)cl_getcap(sp, "smso", &clp->smso);
450 	(void)cl_getcap(sp, "rmso", &clp->rmso);
451 	(void)cl_getcap(sp, "el", &clp->el);
452 	(void)cl_getcap(sp, "cuu1", &clp->cuu1);
453 
454 	/* Enter_standout_mode and exit_standout_mode are paired. */
455 	if (clp->smso == NULL || clp->rmso == NULL) {
456 		if (clp->smso != NULL) {
457 			free(clp->smso);
458 			clp->smso = NULL;
459 		}
460 		if (clp->rmso != NULL) {
461 			free(clp->rmso);
462 			clp->rmso = NULL;
463 		}
464 	}
465 
466 	/*
467 	 * Turn on canonical mode, with normal input and output processing.
468 	 * Start with the original terminal settings as the user probably
469 	 * had them (including any local extensions) set correctly for the
470 	 * current terminal.
471 	 *
472 	 * !!!
473 	 * We can't get everything that we need portably; for example, ONLCR,
474 	 * mapping <newline> to <carriage-return> on output isn't required
475 	 * by POSIX 1003.1b-1993.  If this turns out to be a problem, then
476 	 * we'll either have to play some games on the mapping, or we'll have
477 	 * to make all ex printf's output \r\n instead of \n.
478 	 */
479 	clp->ex_enter = clp->orig;
480 	clp->ex_enter.c_lflag  |= ECHO | ECHOE | ECHOK | ICANON | IEXTEN | ISIG;
481 #ifdef ECHOCTL
482 	clp->ex_enter.c_lflag |= ECHOCTL;
483 #endif
484 #ifdef ECHOKE
485 	clp->ex_enter.c_lflag |= ECHOKE;
486 #endif
487 	clp->ex_enter.c_iflag |= ICRNL;
488 	clp->ex_enter.c_oflag |= OPOST;
489 #ifdef ONLCR
490 	clp->ex_enter.c_oflag |= ONLCR;
491 #endif
492 
493 fast:	if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) {
494 		if (errno == EINTR)
495 			goto fast;
496 		msgq(sp, M_SYSERR, "tcsetattr");
497 		return (1);
498 	}
499 	return (0);
500 }
501 
502 /*
503  * cl_ex_end --
504  *	Shutdown the ex screen.
505  */
506 static int
507 cl_ex_end(gp)
508 	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(sp, name, elementp)
527 	SCR *sp;
528 	char *name, **elementp;
529 {
530 	size_t len;
531 	char *t;
532 
533 	if ((t = tigetstr(name)) != NULL &&
534 	    t != (char *)-1 && (len = strlen(t)) != 0) {
535 		MALLOC_RET(sp, *elementp, char *, len + 1);
536 		memmove(*elementp, t, len + 1);
537 	}
538 	return (0);
539 }
540 
541 /*
542  * cl_freecap --
543  *	Free any allocated termcap/terminfo strings.
544  */
545 static void
546 cl_freecap(clp)
547 	CL_PRIVATE *clp;
548 {
549 	if (clp->el != NULL) {
550 		free(clp->el);
551 		clp->el = NULL;
552 	}
553 	if (clp->cup != NULL) {
554 		free(clp->cup);
555 		clp->cup = NULL;
556 	}
557 	if (clp->cuu1 != NULL) {
558 		free(clp->cuu1);
559 		clp->cuu1 = NULL;
560 	}
561 	if (clp->rmso != NULL) {
562 		free(clp->rmso);
563 		clp->rmso = NULL;
564 	}
565 	if (clp->smso != NULL) {
566 		free(clp->smso);
567 		clp->smso = NULL;
568 	}
569 }
570 
571 /*
572  * cl_putenv --
573  *	Put a value into the environment.
574  */
575 static int
576 cl_putenv(name, str, value)
577 	char *name, *str;
578 	u_long value;
579 
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