1 /*
2 * Copyright (c) 1988 Mark Nudleman
3 * Copyright (c) 1988, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * %sccs.include.redist.c%
7 */
8
9 #ifndef lint
10 static char sccsid[] = "@(#)screen.c 8.2 (Berkeley) 04/20/94";
11 #endif /* not lint */
12
13 /*
14 * Routines which deal with the characteristics of the terminal.
15 * Uses termcap to be as terminal-independent as possible.
16 *
17 * {{ Someday this should be rewritten to use curses. }}
18 */
19
20 #include <stdio.h>
21 #include <less.h>
22
23 #define TERMIOS 1
24
25 #if TERMIO
26 #include <termio.h>
27 #else
28 #if TERMIOS
29 #include <termios.h>
30 #define TAB3 0
31 #include <sys/ioctl.h>
32 #else
33 #include <sgtty.h>
34 #endif
35 #endif
36
37 #ifdef TIOCGWINSZ
38 #include <sys/ioctl.h>
39 #else
40 /*
41 * For the Unix PC (ATT 7300 & 3B1):
42 * Since WIOCGETD is defined in sys/window.h, we can't use that to decide
43 * whether to include sys/window.h. Use SIGPHONE from sys/signal.h instead.
44 */
45 #include <sys/signal.h>
46 #ifdef SIGPHONE
47 #include <sys/window.h>
48 #endif
49 #endif
50
51 /*
52 * Strings passed to tputs() to do various terminal functions.
53 */
54 static char
55 *sc_pad, /* Pad string */
56 *sc_home, /* Cursor home */
57 *sc_addline, /* Add line, scroll down following lines */
58 *sc_lower_left, /* Cursor to last line, first column */
59 *sc_move, /* General cursor positioning */
60 *sc_clear, /* Clear screen */
61 *sc_eol_clear, /* Clear to end of line */
62 *sc_s_in, /* Enter standout (highlighted) mode */
63 *sc_s_out, /* Exit standout mode */
64 *sc_u_in, /* Enter underline mode */
65 *sc_u_out, /* Exit underline mode */
66 *sc_b_in, /* Enter bold mode */
67 *sc_b_out, /* Exit bold mode */
68 *sc_backspace, /* Backspace cursor */
69 *sc_init, /* Startup terminal initialization */
70 *sc_deinit; /* Exit terminal de-intialization */
71
72 int auto_wrap; /* Terminal does \r\n when write past margin */
73 int ignaw; /* Terminal ignores \n immediately after wrap */
74 /* The user's erase and line-kill chars */
75 int retain_below; /* Terminal retains text below the screen */
76 int erase_char, kill_char, werase_char;
77 int sc_width, sc_height = -1; /* Height & width of screen */
78 int sc_window = -1; /* window size for forward and backward */
79 int bo_width, be_width; /* Printing width of boldface sequences */
80 int ul_width, ue_width; /* Printing width of underline sequences */
81 int so_width, se_width; /* Printing width of standout sequences */
82
83 /*
84 * These two variables are sometimes defined in,
85 * and needed by, the termcap library.
86 * It may be necessary on some systems to declare them extern here.
87 */
88 /*extern*/ short ospeed; /* Terminal output baud rate */
89 /*extern*/ char PC; /* Pad character */
90
91 extern int back_scroll;
92 char *tgetstr();
93 char *tgoto();
94
95 /*
96 * Change terminal to "raw mode", or restore to "normal" mode.
97 * "Raw mode" means
98 * 1. An outstanding read will complete on receipt of a single keystroke.
99 * 2. Input is not echoed.
100 * 3. On output, \n is mapped to \r\n.
101 * 4. \t is NOT expanded into spaces.
102 * 5. Signal-causing characters such as ctrl-C (interrupt),
103 * etc. are NOT disabled.
104 * It doesn't matter whether an input \n is mapped to \r, or vice versa.
105 */
raw_mode(on)106 raw_mode(on)
107 int on;
108 {
109 #if TERMIO || TERMIOS
110
111 #if TERMIO
112 struct termio s;
113 static struct termio save_term;
114 #else
115 struct termios s;
116 static struct termios save_term;
117 #endif
118
119 if (on)
120 {
121 /*
122 * Get terminal modes.
123 */
124 #if TERMIO
125 (void)ioctl(2, TCGETA, &s);
126 #else
127 tcgetattr(2, &s);
128 #endif
129
130 /*
131 * Save modes and set certain variables dependent on modes.
132 */
133 save_term = s;
134 #if TERMIO
135 ospeed = s.c_cflag & CBAUD;
136 #else
137 ospeed = cfgetospeed(&s);
138 #endif
139 erase_char = s.c_cc[VERASE];
140 kill_char = s.c_cc[VKILL];
141 werase_char = s.c_cc[VWERASE];
142
143 /*
144 * Set the modes to the way we want them.
145 */
146 s.c_lflag &= ~(ICANON|ECHO|ECHOE|ECHOK|ECHONL);
147 s.c_oflag |= (OPOST|ONLCR|TAB3);
148 #if TERMIO
149 s.c_oflag &= ~(OCRNL|ONOCR|ONLRET);
150 #endif
151 s.c_cc[VMIN] = 1;
152 s.c_cc[VTIME] = 0;
153 } else
154 {
155 /*
156 * Restore saved modes.
157 */
158 s = save_term;
159 }
160 #if TERMIO
161 (void)ioctl(2, TCSETAW, &s);
162 #else
163 tcsetattr(2, TCSADRAIN, &s);
164 #endif
165 #else
166 struct sgttyb s;
167 struct ltchars l;
168 static struct sgttyb save_term;
169
170 if (on)
171 {
172 /*
173 * Get terminal modes.
174 */
175 (void)ioctl(2, TIOCGETP, &s);
176 (void)ioctl(2, TIOCGLTC, &l);
177
178 /*
179 * Save modes and set certain variables dependent on modes.
180 */
181 save_term = s;
182 ospeed = s.sg_ospeed;
183 erase_char = s.sg_erase;
184 kill_char = s.sg_kill;
185 werase_char = l.t_werasc;
186
187 /*
188 * Set the modes to the way we want them.
189 */
190 s.sg_flags |= CBREAK;
191 s.sg_flags &= ~(ECHO|XTABS);
192 } else
193 {
194 /*
195 * Restore saved modes.
196 */
197 s = save_term;
198 }
199 (void)ioctl(2, TIOCSETN, &s);
200 #endif
201 }
202
203 /*
204 * Get terminal capabilities via termcap.
205 */
get_term()206 get_term()
207 {
208 char termbuf[2048];
209 char *sp;
210 char *term;
211 int hard;
212 #ifdef TIOCGWINSZ
213 struct winsize w;
214 #else
215 #ifdef WIOCGETD
216 struct uwdata w;
217 #endif
218 #endif
219 static char sbuf[1024];
220
221 char *getenv(), *strcpy();
222
223 /*
224 * Find out what kind of terminal this is.
225 */
226 if ((term = getenv("TERM")) == NULL)
227 term = "unknown";
228 if (tgetent(termbuf, term) <= 0)
229 (void)strcpy(termbuf, "dumb:co#80:hc:");
230
231 /*
232 * Get size of the screen.
233 */
234 #ifdef TIOCGWINSZ
235 if (ioctl(2, TIOCGWINSZ, &w) == 0 && w.ws_row > 0)
236 sc_height = w.ws_row;
237 #else
238 #ifdef WIOCGETD
239 if (ioctl(2, WIOCGETD, &w) == 0 && w.uw_height > 0)
240 sc_height = w.uw_height/w.uw_vs;
241 #endif
242 #endif
243 else
244 sc_height = tgetnum("li");
245 hard = (sc_height < 0 || tgetflag("hc"));
246 if (hard) {
247 /* Oh no, this is a hardcopy terminal. */
248 sc_height = 24;
249 }
250
251 #ifdef TIOCGWINSZ
252 if (ioctl(2, TIOCGWINSZ, &w) == 0 && w.ws_col > 0)
253 sc_width = w.ws_col;
254 else
255 #ifdef WIOCGETD
256 if (ioctl(2, WIOCGETD, &w) == 0 && w.uw_width > 0)
257 sc_width = w.uw_width/w.uw_hs;
258 else
259 #endif
260 #endif
261 sc_width = tgetnum("co");
262 if (sc_width < 0)
263 sc_width = 80;
264
265 auto_wrap = tgetflag("am");
266 ignaw = tgetflag("xn");
267 retain_below = tgetflag("db");
268
269 /*
270 * Assumes termcap variable "sg" is the printing width of
271 * the standout sequence, the end standout sequence,
272 * the underline sequence, the end underline sequence,
273 * the boldface sequence, and the end boldface sequence.
274 */
275 if ((so_width = tgetnum("sg")) < 0)
276 so_width = 0;
277 be_width = bo_width = ue_width = ul_width = se_width = so_width;
278
279 /*
280 * Get various string-valued capabilities.
281 */
282 sp = sbuf;
283
284 sc_pad = tgetstr("pc", &sp);
285 if (sc_pad != NULL)
286 PC = *sc_pad;
287
288 sc_init = tgetstr("ti", &sp);
289 if (sc_init == NULL)
290 sc_init = "";
291
292 sc_deinit= tgetstr("te", &sp);
293 if (sc_deinit == NULL)
294 sc_deinit = "";
295
296 sc_eol_clear = tgetstr("ce", &sp);
297 if (hard || sc_eol_clear == NULL || *sc_eol_clear == '\0')
298 {
299 sc_eol_clear = "";
300 }
301
302 sc_clear = tgetstr("cl", &sp);
303 if (hard || sc_clear == NULL || *sc_clear == '\0')
304 {
305 sc_clear = "\n\n";
306 }
307
308 sc_move = tgetstr("cm", &sp);
309 if (hard || sc_move == NULL || *sc_move == '\0')
310 {
311 /*
312 * This is not an error here, because we don't
313 * always need sc_move.
314 * We need it only if we don't have home or lower-left.
315 */
316 sc_move = "";
317 }
318
319 sc_s_in = tgetstr("so", &sp);
320 if (hard || sc_s_in == NULL)
321 sc_s_in = "";
322
323 sc_s_out = tgetstr("se", &sp);
324 if (hard || sc_s_out == NULL)
325 sc_s_out = "";
326
327 sc_u_in = tgetstr("us", &sp);
328 if (hard || sc_u_in == NULL)
329 sc_u_in = sc_s_in;
330
331 sc_u_out = tgetstr("ue", &sp);
332 if (hard || sc_u_out == NULL)
333 sc_u_out = sc_s_out;
334
335 sc_b_in = tgetstr("md", &sp);
336 if (hard || sc_b_in == NULL)
337 {
338 sc_b_in = sc_s_in;
339 sc_b_out = sc_s_out;
340 } else
341 {
342 sc_b_out = tgetstr("me", &sp);
343 if (hard || sc_b_out == NULL)
344 sc_b_out = "";
345 }
346
347 sc_home = tgetstr("ho", &sp);
348 if (hard || sc_home == NULL || *sc_home == '\0')
349 {
350 if (*sc_move == '\0')
351 {
352 /*
353 * This last resort for sc_home is supposed to
354 * be an up-arrow suggesting moving to the
355 * top of the "virtual screen". (The one in
356 * your imagination as you try to use this on
357 * a hard copy terminal.)
358 */
359 sc_home = "|\b^";
360 } else
361 {
362 /*
363 * No "home" string,
364 * but we can use "move(0,0)".
365 */
366 (void)strcpy(sp, tgoto(sc_move, 0, 0));
367 sc_home = sp;
368 sp += strlen(sp) + 1;
369 }
370 }
371
372 sc_lower_left = tgetstr("ll", &sp);
373 if (hard || sc_lower_left == NULL || *sc_lower_left == '\0')
374 {
375 if (*sc_move == '\0')
376 {
377 sc_lower_left = "\r";
378 } else
379 {
380 /*
381 * No "lower-left" string,
382 * but we can use "move(0,last-line)".
383 */
384 (void)strcpy(sp, tgoto(sc_move, 0, sc_height-1));
385 sc_lower_left = sp;
386 sp += strlen(sp) + 1;
387 }
388 }
389
390 /*
391 * To add a line at top of screen and scroll the display down,
392 * we use "al" (add line) or "sr" (scroll reverse).
393 */
394 if ((sc_addline = tgetstr("al", &sp)) == NULL ||
395 *sc_addline == '\0')
396 sc_addline = tgetstr("sr", &sp);
397
398 if (hard || sc_addline == NULL || *sc_addline == '\0')
399 {
400 sc_addline = "";
401 /* Force repaint on any backward movement */
402 back_scroll = 0;
403 }
404
405 if (tgetflag("bs"))
406 sc_backspace = "\b";
407 else
408 {
409 sc_backspace = tgetstr("bc", &sp);
410 if (sc_backspace == NULL || *sc_backspace == '\0')
411 sc_backspace = "\b";
412 }
413 }
414
415
416 /*
417 * Below are the functions which perform all the
418 * terminal-specific screen manipulation.
419 */
420
421 int putchr();
422
423 /*
424 * Initialize terminal
425 */
init()426 init()
427 {
428 tputs(sc_init, sc_height, putchr);
429 }
430
431 /*
432 * Deinitialize terminal
433 */
deinit()434 deinit()
435 {
436 tputs(sc_deinit, sc_height, putchr);
437 }
438
439 /*
440 * Home cursor (move to upper left corner of screen).
441 */
home()442 home()
443 {
444 tputs(sc_home, 1, putchr);
445 }
446
447 /*
448 * Add a blank line (called with cursor at home).
449 * Should scroll the display down.
450 */
add_line()451 add_line()
452 {
453 tputs(sc_addline, sc_height, putchr);
454 }
455
456 int short_file; /* if file less than a screen */
lower_left()457 lower_left()
458 {
459 if (short_file) {
460 putchr('\r');
461 flush();
462 }
463 else
464 tputs(sc_lower_left, 1, putchr);
465 }
466
467 /*
468 * Ring the terminal bell.
469 */
bell()470 bell()
471 {
472 putchr('\7');
473 }
474
475 /*
476 * Clear the screen.
477 */
clear()478 clear()
479 {
480 tputs(sc_clear, sc_height, putchr);
481 }
482
483 /*
484 * Clear from the cursor to the end of the cursor's line.
485 * {{ This must not move the cursor. }}
486 */
clear_eol()487 clear_eol()
488 {
489 tputs(sc_eol_clear, 1, putchr);
490 }
491
492 /*
493 * Begin "standout" (bold, underline, or whatever).
494 */
so_enter()495 so_enter()
496 {
497 tputs(sc_s_in, 1, putchr);
498 }
499
500 /*
501 * End "standout".
502 */
so_exit()503 so_exit()
504 {
505 tputs(sc_s_out, 1, putchr);
506 }
507
508 /*
509 * Begin "underline" (hopefully real underlining,
510 * otherwise whatever the terminal provides).
511 */
ul_enter()512 ul_enter()
513 {
514 tputs(sc_u_in, 1, putchr);
515 }
516
517 /*
518 * End "underline".
519 */
ul_exit()520 ul_exit()
521 {
522 tputs(sc_u_out, 1, putchr);
523 }
524
525 /*
526 * Begin "bold"
527 */
bo_enter()528 bo_enter()
529 {
530 tputs(sc_b_in, 1, putchr);
531 }
532
533 /*
534 * End "bold".
535 */
bo_exit()536 bo_exit()
537 {
538 tputs(sc_b_out, 1, putchr);
539 }
540
541 /*
542 * Erase the character to the left of the cursor
543 * and move the cursor left.
544 */
backspace()545 backspace()
546 {
547 /*
548 * Try to erase the previous character by overstriking with a space.
549 */
550 tputs(sc_backspace, 1, putchr);
551 putchr(' ');
552 tputs(sc_backspace, 1, putchr);
553 }
554
555 /*
556 * Output a plain backspace, without erasing the previous char.
557 */
putbs()558 putbs()
559 {
560 tputs(sc_backspace, 1, putchr);
561 }
562