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      1 /*	$NetBSD: screen.c,v 1.7 2003/10/13 14:34:25 agc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988 Mark Nudelman
      5  * Copyright (c) 1988, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the University nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 #ifndef lint
     35 #if 0
     36 static char sccsid[] = "@(#)screen.c	8.2 (Berkeley) 4/20/94";
     37 #else
     38 __RCSID("$NetBSD: screen.c,v 1.7 2003/10/13 14:34:25 agc Exp $");
     39 #endif
     40 #endif /* not lint */
     41 
     42 /*
     43  * Routines which deal with the characteristics of the terminal.
     44  * Uses termcap to be as terminal-independent as possible.
     45  *
     46  * {{ Someday this should be rewritten to use curses. }}
     47  */
     48 
     49 #include <stdio.h>
     50 #include <string.h>
     51 #include <stdlib.h>
     52 #include <unistd.h>
     53 
     54 #include "less.h"
     55 #include "extern.h"
     56 
     57 #define TERMIOS 1
     58 
     59 #if TERMIO
     60 #include <termio.h>
     61 #else
     62 #if TERMIOS
     63 #include <termios.h>
     64 #define TAB3 0
     65 #include <sys/ioctl.h>
     66 #else
     67 #include <sgtty.h>
     68 #endif
     69 #endif
     70 #ifdef __NetBSD__
     71 #include <termcap.h>
     72 #endif
     73 
     74 #ifdef TIOCGWINSZ
     75 #include <sys/ioctl.h>
     76 #else
     77 /*
     78  * For the Unix PC (ATT 7300 & 3B1):
     79  * Since WIOCGETD is defined in sys/window.h, we can't use that to decide
     80  * whether to include sys/window.h.  Use SIGPHONE from sys/signal.h instead.
     81  */
     82 #include <sys/signal.h>
     83 #ifdef SIGPHONE
     84 #include <sys/window.h>
     85 #endif
     86 #endif
     87 
     88 /*
     89  * Strings passed to tputs() to do various terminal functions.
     90  */
     91 static char
     92 	*sc_pad,		/* Pad string */
     93 	*sc_home,		/* Cursor home */
     94 	*sc_addline,		/* Add line, scroll down following lines */
     95 	*sc_lower_left,		/* Cursor to last line, first column */
     96 	*sc_move,		/* General cursor positioning */
     97 	*sc_clear,		/* Clear screen */
     98 	*sc_eol_clear,		/* Clear to end of line */
     99 	*sc_s_in,		/* Enter standout (highlighted) mode */
    100 	*sc_s_out,		/* Exit standout mode */
    101 	*sc_u_in,		/* Enter underline mode */
    102 	*sc_u_out,		/* Exit underline mode */
    103 	*sc_b_in,		/* Enter bold mode */
    104 	*sc_b_out,		/* Exit bold mode */
    105 	*sc_backspace,		/* Backspace cursor */
    106 	*sc_init,		/* Startup terminal initialization */
    107 	*sc_deinit;		/* Exit terminal de-intialization */
    108 
    109 int auto_wrap;			/* Terminal does \r\n when write past margin */
    110 int ignaw;			/* Terminal ignores \n immediately after wrap */
    111 				/* The user's erase and line-kill chars */
    112 int retain_below;		/* Terminal retains text below the screen */
    113 int erase_char, kill_char, werase_char;
    114 int sc_width, sc_height = -1;	/* Height & width of screen */
    115 int sc_window = -1;		/* window size for forward and backward */
    116 int bo_width, be_width;		/* Printing width of boldface sequences */
    117 int ul_width, ue_width;		/* Printing width of underline sequences */
    118 int so_width, se_width;		/* Printing width of standout sequences */
    119 
    120 /*
    121  * These two variables are sometimes defined in,
    122  * and needed by, the termcap library.
    123  * It may be necessary on some systems to declare them extern here.
    124  */
    125 /*extern*/ short ospeed;	/* Terminal output baud rate */
    126 /*extern*/ char PC;		/* Pad character */
    127 
    128 /*
    129  * Change terminal to "raw mode", or restore to "normal" mode.
    130  * "Raw mode" means
    131  *	1. An outstanding read will complete on receipt of a single keystroke.
    132  *	2. Input is not echoed.
    133  *	3. On output, \n is mapped to \r\n.
    134  *	4. \t is NOT expanded into spaces.
    135  *	5. Signal-causing characters such as ctrl-C (interrupt),
    136  *	   etc. are NOT disabled.
    137  * It doesn't matter whether an input \n is mapped to \r, or vice versa.
    138  */
    139 void
    140 raw_mode(on)
    141 	int on;
    142 {
    143 #if TERMIO || TERMIOS
    144 
    145 #if TERMIO
    146 	struct termio s;
    147 	static struct termio save_term;
    148 #else
    149 	struct termios s;
    150 	static struct termios save_term;
    151 #endif
    152 
    153 	if (on)
    154 	{
    155 		/*
    156 		 * Get terminal modes.
    157 		 */
    158 #if TERMIO
    159 		(void)ioctl(2, TCGETA, &s);
    160 #else
    161 		tcgetattr(2, &s);
    162 #endif
    163 
    164 		/*
    165 		 * Save modes and set certain variables dependent on modes.
    166 		 */
    167 		save_term = s;
    168 #if TERMIO
    169 		ospeed = s.c_cflag & CBAUD;
    170 #else
    171 		ospeed = cfgetospeed(&s);
    172 #endif
    173 		erase_char = s.c_cc[VERASE];
    174 		kill_char = s.c_cc[VKILL];
    175 		werase_char = s.c_cc[VWERASE];
    176 
    177 		/*
    178 		 * Set the modes to the way we want them.
    179 		 */
    180 		s.c_lflag &= ~(ICANON|ECHO|ECHOE|ECHOK|ECHONL);
    181 		s.c_oflag |=  (OPOST|ONLCR|TAB3);
    182 #if TERMIO
    183 		s.c_oflag &= ~(OCRNL|ONOCR|ONLRET);
    184 #endif
    185 		s.c_cc[VMIN] = 1;
    186 		s.c_cc[VTIME] = 0;
    187 	} else
    188 	{
    189 		/*
    190 		 * Restore saved modes.
    191 		 */
    192 		s = save_term;
    193 	}
    194 #if TERMIO
    195 	(void)ioctl(2, TCSETAW, &s);
    196 #else
    197 	tcsetattr(2, TCSADRAIN, &s);
    198 #endif
    199 #else
    200 	struct sgttyb s;
    201 	struct ltchars l;
    202 	static struct sgttyb save_term;
    203 
    204 	if (on)
    205 	{
    206 		/*
    207 		 * Get terminal modes.
    208 		 */
    209 		(void)ioctl(2, TIOCGETP, &s);
    210 		(void)ioctl(2, TIOCGLTC, &l);
    211 
    212 		/*
    213 		 * Save modes and set certain variables dependent on modes.
    214 		 */
    215 		save_term = s;
    216 		ospeed = s.sg_ospeed;
    217 		erase_char = s.sg_erase;
    218 		kill_char = s.sg_kill;
    219 		werase_char = l.t_werasc;
    220 
    221 		/*
    222 		 * Set the modes to the way we want them.
    223 		 */
    224 		s.sg_flags |= CBREAK;
    225 		s.sg_flags &= ~(ECHO|XTABS);
    226 	} else
    227 	{
    228 		/*
    229 		 * Restore saved modes.
    230 		 */
    231 		s = save_term;
    232 	}
    233 	(void)ioctl(2, TIOCSETN, &s);
    234 #endif
    235 }
    236 
    237 /*
    238  * Get terminal capabilities via termcap.
    239  */
    240 void
    241 get_term()
    242 {
    243 	char termbuf[2048];
    244 	char *sp;
    245 	char *term;
    246 	int hard;
    247 #ifdef TIOCGWINSZ
    248 	struct winsize w;
    249 #else
    250 #ifdef WIOCGETD
    251 	struct uwdata w;
    252 #endif
    253 #endif
    254 	static char sbuf[1024];
    255 
    256 	/*
    257 	 * Find out what kind of terminal this is.
    258 	 */
    259  	if ((term = getenv("TERM")) == NULL)
    260  		term = "unknown";
    261  	if (tgetent(termbuf, term) <= 0)
    262  		(void)strlcpy(termbuf, "dumb:co#80:hc:", sizeof(termbuf));
    263 
    264 	/*
    265 	 * Get size of the screen.
    266 	 */
    267 #ifdef TIOCGWINSZ
    268 	if (ioctl(2, TIOCGWINSZ, &w) == 0 && w.ws_row > 0)
    269 		sc_height = w.ws_row;
    270 #else
    271 #ifdef WIOCGETD
    272 	if (ioctl(2, WIOCGETD, &w) == 0 && w.uw_height > 0)
    273 		sc_height = w.uw_height/w.uw_vs;
    274 #endif
    275 #endif
    276 	else
    277 		sc_height = tgetnum("li");
    278 	hard = (sc_height < 0 || tgetflag("hc"));
    279 	if (hard) {
    280 		/* Oh no, this is a hardcopy terminal. */
    281 		sc_height = 24;
    282 	}
    283 
    284 #ifdef TIOCGWINSZ
    285  	if (ioctl(2, TIOCGWINSZ, &w) == 0 && w.ws_col > 0)
    286 		sc_width = w.ws_col;
    287 	else
    288 #ifdef WIOCGETD
    289 	if (ioctl(2, WIOCGETD, &w) == 0 && w.uw_width > 0)
    290 		sc_width = w.uw_width/w.uw_hs;
    291 	else
    292 #endif
    293 #endif
    294  		sc_width = tgetnum("co");
    295  	if (sc_width < 0)
    296   		sc_width = 80;
    297 
    298 	auto_wrap = tgetflag("am");
    299 	ignaw = tgetflag("xn");
    300 	retain_below = tgetflag("db");
    301 
    302 	/*
    303 	 * Assumes termcap variable "sg" is the printing width of
    304 	 * the standout sequence, the end standout sequence,
    305 	 * the underline sequence, the end underline sequence,
    306 	 * the boldface sequence, and the end boldface sequence.
    307 	 */
    308 	if ((so_width = tgetnum("sg")) < 0)
    309 		so_width = 0;
    310 	be_width = bo_width = ue_width = ul_width = se_width = so_width;
    311 
    312 	/*
    313 	 * Get various string-valued capabilities.
    314 	 */
    315 	sp = sbuf;
    316 
    317 	sc_pad = tgetstr("pc", &sp);
    318 	if (sc_pad != NULL)
    319 		PC = *sc_pad;
    320 
    321 	sc_init = tgetstr("ti", &sp);
    322 	if (sc_init == NULL)
    323 		sc_init = "";
    324 
    325 	sc_deinit= tgetstr("te", &sp);
    326 	if (sc_deinit == NULL)
    327 		sc_deinit = "";
    328 
    329 	sc_eol_clear = tgetstr("ce", &sp);
    330 	if (hard || sc_eol_clear == NULL || *sc_eol_clear == '\0')
    331 	{
    332 		sc_eol_clear = "";
    333 	}
    334 
    335 	sc_clear = tgetstr("cl", &sp);
    336 	if (hard || sc_clear == NULL || *sc_clear == '\0')
    337 	{
    338 		sc_clear = "\n\n";
    339 	}
    340 
    341 	sc_move = tgetstr("cm", &sp);
    342 	if (hard || sc_move == NULL || *sc_move == '\0')
    343 	{
    344 		/*
    345 		 * This is not an error here, because we don't
    346 		 * always need sc_move.
    347 		 * We need it only if we don't have home or lower-left.
    348 		 */
    349 		sc_move = "";
    350 	}
    351 
    352 	sc_s_in = tgetstr("so", &sp);
    353 	if (hard || sc_s_in == NULL)
    354 		sc_s_in = "";
    355 
    356 	sc_s_out = tgetstr("se", &sp);
    357 	if (hard || sc_s_out == NULL)
    358 		sc_s_out = "";
    359 
    360 	sc_u_in = tgetstr("us", &sp);
    361 	if (hard || sc_u_in == NULL)
    362 		sc_u_in = sc_s_in;
    363 
    364 	sc_u_out = tgetstr("ue", &sp);
    365 	if (hard || sc_u_out == NULL)
    366 		sc_u_out = sc_s_out;
    367 
    368 	sc_b_in = tgetstr("md", &sp);
    369 	if (hard || sc_b_in == NULL)
    370 	{
    371 		sc_b_in = sc_s_in;
    372 		sc_b_out = sc_s_out;
    373 	} else
    374 	{
    375 		sc_b_out = tgetstr("me", &sp);
    376 		if (hard || sc_b_out == NULL)
    377 			sc_b_out = "";
    378 	}
    379 
    380 	sc_home = tgetstr("ho", &sp);
    381 	if (hard || sc_home == NULL || *sc_home == '\0')
    382 	{
    383 		if (*sc_move == '\0')
    384 		{
    385 			/*
    386 			 * This last resort for sc_home is supposed to
    387 			 * be an up-arrow suggesting moving to the
    388 			 * top of the "virtual screen". (The one in
    389 			 * your imagination as you try to use this on
    390 			 * a hard copy terminal.)
    391 			 */
    392 			sc_home = "|\b^";
    393 		} else
    394 		{
    395 			/*
    396 			 * No "home" string,
    397 			 * but we can use "move(0,0)".
    398 			 */
    399 			(void)strlcpy(sp, tgoto(sc_move, 0, 0),
    400 			    sizeof(sbuf) - (sp - sbuf));
    401 			sc_home = sp;
    402 			sp += strlen(sp) + 1;
    403 		}
    404 	}
    405 
    406 	sc_lower_left = tgetstr("ll", &sp);
    407 	if (hard || sc_lower_left == NULL || *sc_lower_left == '\0')
    408 	{
    409 		if (*sc_move == '\0')
    410 		{
    411 			sc_lower_left = "\r";
    412 		} else
    413 		{
    414 			/*
    415 			 * No "lower-left" string,
    416 			 * but we can use "move(0,last-line)".
    417 			 */
    418 			(void)strlcpy(sp, tgoto(sc_move, 0, sc_height-1),
    419 			    sizeof(sbuf) - (sp - sbuf));
    420 			sc_lower_left = sp;
    421 			sp += strlen(sp) + 1;
    422 		}
    423 	}
    424 
    425 	/*
    426 	 * To add a line at top of screen and scroll the display down,
    427 	 * we use "al" (add line) or "sr" (scroll reverse).
    428 	 */
    429 	if ((sc_addline = tgetstr("al", &sp)) == NULL ||
    430 		 *sc_addline == '\0')
    431 		sc_addline = tgetstr("sr", &sp);
    432 
    433 	if (hard || sc_addline == NULL || *sc_addline == '\0')
    434 	{
    435 		sc_addline = "";
    436 		/* Force repaint on any backward movement */
    437 		back_scroll = 0;
    438 	}
    439 
    440 	if (tgetflag("bs"))
    441 		sc_backspace = "\b";
    442 	else
    443 	{
    444 		sc_backspace = tgetstr("bc", &sp);
    445 		if (sc_backspace == NULL || *sc_backspace == '\0')
    446 			sc_backspace = "\b";
    447 	}
    448 }
    449 
    450 
    451 /*
    452  * Below are the functions which perform all the
    453  * terminal-specific screen manipulation.
    454  */
    455 
    456 /*
    457  * Initialize terminal
    458  */
    459 void
    460 init()
    461 {
    462 	tputs(sc_init, sc_height, putchr);
    463 }
    464 
    465 /*
    466  * Deinitialize terminal
    467  */
    468 void
    469 deinit()
    470 {
    471 	tputs(sc_deinit, sc_height, putchr);
    472 }
    473 
    474 /*
    475  * Home cursor (move to upper left corner of screen).
    476  */
    477 void
    478 home()
    479 {
    480 	tputs(sc_home, 1, putchr);
    481 }
    482 
    483 /*
    484  * Add a blank line (called with cursor at home).
    485  * Should scroll the display down.
    486  */
    487 void
    488 add_line()
    489 {
    490 	tputs(sc_addline, sc_height, putchr);
    491 }
    492 
    493 int short_file;				/* if file less than a screen */
    494 void
    495 lower_left()
    496 {
    497 	if (short_file) {
    498 		putchr('\r');
    499 		flush();
    500 	}
    501 	else
    502 		tputs(sc_lower_left, 1, putchr);
    503 }
    504 
    505 /*
    506  * Ring the terminal bell.
    507  */
    508 void
    509 bell()
    510 {
    511 	putchr('\7');
    512 }
    513 
    514 /*
    515  * Clear the screen.
    516  */
    517 void
    518 clear()
    519 {
    520 	tputs(sc_clear, sc_height, putchr);
    521 }
    522 
    523 /*
    524  * Clear from the cursor to the end of the cursor's line.
    525  * {{ This must not move the cursor. }}
    526  */
    527 void
    528 clear_eol()
    529 {
    530 	tputs(sc_eol_clear, 1, putchr);
    531 }
    532 
    533 /*
    534  * Begin "standout" (bold, underline, or whatever).
    535  */
    536 void
    537 so_enter()
    538 {
    539 	tputs(sc_s_in, 1, putchr);
    540 }
    541 
    542 /*
    543  * End "standout".
    544  */
    545 void
    546 so_exit()
    547 {
    548 	tputs(sc_s_out, 1, putchr);
    549 }
    550 
    551 /*
    552  * Begin "underline" (hopefully real underlining,
    553  * otherwise whatever the terminal provides).
    554  */
    555 void
    556 ul_enter()
    557 {
    558 	tputs(sc_u_in, 1, putchr);
    559 }
    560 
    561 /*
    562  * End "underline".
    563  */
    564 void
    565 ul_exit()
    566 {
    567 	tputs(sc_u_out, 1, putchr);
    568 }
    569 
    570 /*
    571  * Begin "bold"
    572  */
    573 void
    574 bo_enter()
    575 {
    576 	tputs(sc_b_in, 1, putchr);
    577 }
    578 
    579 /*
    580  * End "bold".
    581  */
    582 void
    583 bo_exit()
    584 {
    585 	tputs(sc_b_out, 1, putchr);
    586 }
    587 
    588 /*
    589  * Erase the character to the left of the cursor
    590  * and move the cursor left.
    591  */
    592 void
    593 backspace()
    594 {
    595 	/*
    596 	 * Try to erase the previous character by overstriking with a space.
    597 	 */
    598 	tputs(sc_backspace, 1, putchr);
    599 	putchr(' ');
    600 	tputs(sc_backspace, 1, putchr);
    601 }
    602 
    603 /*
    604  * Output a plain backspace, without erasing the previous char.
    605  */
    606 void
    607 putbs()
    608 {
    609 	tputs(sc_backspace, 1, putchr);
    610 }
    611