screen.c

/*
 * Copyright (C) 1984-2026  Mark Nudelman
 *
 * You may distribute under the terms of either the GNU General Public
 * License or the Less License, as specified in the README file.
 *
 * For more information, see the README file.
 */


/*
 * Routines which deal with the characteristics of the terminal.
 * Uses termcap to be as terminal-independent as possible.
 */

#include "less.h"
#include "cmd.h"

#if MSDOS_COMPILER
#include "pckeys.h"
#if MSDOS_COMPILER==MSOFTC
#include <graph.h>
#else
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
#include <conio.h>
#if MSDOS_COMPILER==DJGPPC
#include <pc.h>
extern int fd0;
#endif
#else
#if MSDOS_COMPILER==WIN32C
#include <windows.h>
#endif
#endif
#endif
#include <time.h>

#ifndef FOREGROUND_BLUE
#define FOREGROUND_BLUE      0x0001	
#endif
#ifndef FOREGROUND_GREEN
#define FOREGROUND_GREEN     0x0002	
#endif
#ifndef FOREGROUND_RED
#define FOREGROUND_RED       0x0004	
#endif
#ifndef FOREGROUND_INTENSITY
#define FOREGROUND_INTENSITY 0x0008
#endif

#else

#if HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#if HAVE_TERMIOS_H && HAVE_TERMIOS_FUNCS
#include <termios.h>
#else
#if HAVE_TERMIO_H
#include <termio.h>
#else
#if HAVE_SGSTAT_H
#include <sgstat.h>
#else
#include <sgtty.h>
#endif
#endif
#endif

#if HAVE_TERMINFO && !USE_TERMCAP
#define USE_TERMINFO 1
#endif

#if USE_TERMINFO
#include <curses.h>
#include <term.h>
#if HAVE_TPARM2
#define LTPARM2(s,p1,p2) tparm(s, p1, p2)
#else
#if HAVE_TPARM8
#define LTPARM2(s,p1,p2) tparm(s, p1, p2, 0, 0, 0, 0, 0, 0)
#else
#if HAVE_TPARM9
#define LTPARM2(s,p1,p2) tparm(s, p1, p2, 0, 0, 0, 0, 0, 0, 0)
#else
#endif
#endif
#endif
#else
#if HAVE_NCURSESW_TERMCAP_H
#include <ncursesw/termcap.h>
#else
#if HAVE_NCURSES_TERMCAP_H
#include <ncurses/termcap.h>
#else
#if HAVE_TERMCAP_H
#include <termcap.h>
#endif
#endif
#endif
#endif
#ifdef _OSK
#include <signal.h>
#endif
#if OS2
#include <sys/signal.h>
#include "pckeys.h"
#endif
#if HAVE_SYS_STREAM_H
#include <sys/stream.h>
#endif
#if HAVE_SYS_PTEM_H
#include <sys/ptem.h>
#endif

#endif /* MSDOS_COMPILER */

/*
 * Check for broken termios package that forces you to manually
 * set the line discipline.
 */
#ifdef __ultrix__
#define MUST_SET_LINE_DISCIPLINE 1
#else
#define MUST_SET_LINE_DISCIPLINE 0
#endif

#if OS2
#define DEFAULT_TERM            "ansi"
static char *windowid;
#else
#define DEFAULT_TERM            "unknown"
#endif

#if MSDOS_COMPILER==MSOFTC
static int videopages;
static long msec_loops;
static int flash_created = 0;
#define SET_FG_COLOR(fg)        _settextcolor(fg)
#define SET_BG_COLOR(bg)        _setbkcolor(bg)
#define SETCOLORS(fg,bg)        { SET_FG_COLOR(fg); SET_BG_COLOR(bg); }
#endif

#if MSDOS_COMPILER==BORLANDC
static unsigned short *whitescreen;
static int flash_created = 0;
#endif
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
#define _settextposition(y,x)   gotoxy(x,y)
#define _clearscreen(m)         clrscr()
#define _outtext(s)             cputs(s)
#define SET_FG_COLOR(fg)        textcolor(fg)
#define SET_BG_COLOR(bg)        textbackground(bg)
#define SETCOLORS(fg,bg)        { SET_FG_COLOR(fg); SET_BG_COLOR(bg); }
extern int sc_height;
#endif

#if MSDOS_COMPILER==WIN32C
#define UTF8_MAX_LENGTH 4

static WORD curr_attr;

static HANDLE con_out_save = INVALID_HANDLE_VALUE; /* previous console */
static HANDLE con_out_ours = INVALID_HANDLE_VALUE; /* our own */
HANDLE con_out = INVALID_HANDLE_VALUE;             /* current console */

extern int utf_mode;
extern lbool quitting;
static void win32_init_term();
static void win32_deinit_term();

#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 4
#endif

#define FG_COLORS       (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY)
#define BG_COLORS       (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE | BACKGROUND_INTENSITY)
#define MAKEATTR(fg,bg)         ((WORD)((fg)|((bg)<<4)))
#define APPLY_COLORS()          { if (SetConsoleTextAttribute(con_out, curr_attr) == 0) \
                                  error("SETCOLORS failed", NULL_PARG); }
#define SET_FG_COLOR(fg)        { curr_attr &= ~0x0f; curr_attr |= (fg); APPLY_COLORS(); }
#define SET_BG_COLOR(bg)        { curr_attr &= ~0xf0; curr_attr |= ((bg)<<4); APPLY_COLORS(); }
#define SETCOLORS(fg,bg)        { curr_attr = MAKEATTR(fg,bg); APPLY_COLORS(); }
#endif

#if MSDOS_COMPILER
public int nm_fg_color = CV_ERROR; /* Color of normal text */
public int nm_bg_color = CV_ERROR;
public int nm_attr = 0;
public int bo_fg_color = CV_ERROR; /* Color of bold text */
public int bo_bg_color = CV_ERROR;
public int bo_attr = 0;
public int ul_fg_color = CV_ERROR; /* Color of underlined text */
public int ul_bg_color = CV_ERROR;
public int ul_attr = 0;
public int so_fg_color = CV_ERROR; /* Color of standout text */
public int so_bg_color = CV_ERROR;
public int so_attr = 0;
public int bl_fg_color = CV_ERROR; /* Color of blinking text */
public int bl_bg_color = CV_ERROR;
public int bl_attr = 0;
static int sy_fg_color;            /* Color of system text (before less) */
static int sy_bg_color;
public int sgr_mode;            /* Honor ANSI sequences rather than using above */
#if MSDOS_COMPILER==WIN32C
static DWORD init_console_output_mode;
extern DWORD init_console_input_mode;
extern DWORD curr_console_input_mode;
extern DWORD base_console_input_mode;
extern DWORD mouse_console_input_mode;
public int vt_enabled = -1;     /* Is virtual terminal processing available? */
#endif
#else

/*
 * These two variables are sometimes defined in,
 * and needed by, the termcap library.
 */
#if USE_TERMINFO
#undef HAVE_OSPEED
#else
#if MUST_DEFINE_OSPEED
extern short ospeed;    /* Terminal output baud rate */
extern char PC;         /* Pad character */
#endif
#ifdef _OSK
short ospeed;
char PC_, *UP, *BC;
#endif
#endif

/*
 * Strings passed to tputs() to do various terminal functions.
 */
static constant char
#if HAVE_OSPEED
	*sc_pad,                /* Pad string */
#endif
	*sc_home,               /* Cursor home */
	*sc_addline,            /* Add line, scroll down following lines */
	*sc_lower_left,         /* Cursor to last line, first column */
	*sc_return,             /* Cursor to beginning of current line */
	*sc_move,               /* General cursor positioning */
	*sc_clear,              /* Clear screen */
	*sc_eol_clear,          /* Clear to end of line */
	*sc_eos_clear,          /* Clear to end of screen */
	*sc_s_in,               /* Enter standout (highlighted) mode */
	*sc_s_out,              /* Exit standout mode */
	*sc_u_in,               /* Enter underline mode */
	*sc_u_out,              /* Exit underline mode */
	*sc_b_in,               /* Enter bold mode */
	*sc_b_out,              /* Exit bold mode */
	*sc_bl_in,              /* Enter blink mode */
	*sc_bl_out,             /* Exit blink mode */
	*sc_visual_bell,        /* Visual bell (flash screen) sequence */
	*sc_backspace,          /* Backspace cursor */
	*sc_s_keypad,           /* Start keypad mode */
	*sc_e_keypad,           /* End keypad mode */
	*sc_s_mousecap,         /* Start mouse capture mode */
	*sc_e_mousecap,         /* End mouse capture mode */
	*sc_s_bracketed_paste,  /* Start bracketed paste mode */
	*sc_e_bracketed_paste,  /* End bracketed paste mode */
	*sc_suspend,            /* Suspend screen updates */
	*sc_resume,             /* Resume screen updates */
	*sc_init,               /* Startup terminal initialization */
	*sc_deinit;             /* Exit terminal de-initialization */

/* attrbits is the current attribute mode of the terminal
 * (AT_UNDERLINE, AT_BOLD, AT_STANDOUT, AT_BLINK).
 * attrmode is the user-defined mode, which may include AT_COLOR values,
 * and the mapping of the AT_COLOR value may include the 4 attribute bits. */
static int attrbits = 0;
static int attrcolor = -1;
#endif

/* term_init has been called; terminal is ready for use by less */
static lbool term_init_done = FALSE;
public lbool term_init_ever = FALSE;

public int auto_wrap;           /* Terminal does \r\n when write past margin */
public int defer_wrap;          /* After printing char in last column, doesn't wrap until next char */
public int erase_char;          /* The user's erase char */
public int erase2_char;         /* The user's other erase char */
public int kill_char;           /* The user's line-kill char */
public int werase_char;         /* The user's word-erase char */
public int sc_width, sc_height; /* Height & width of screen */
public int bo_s_width, bo_e_width;      /* Printing width of boldface seq */
public int ul_s_width, ul_e_width;      /* Printing width of underline seq */
public int so_s_width, so_e_width;      /* Printing width of standout seq */
public int bl_s_width, bl_e_width;      /* Printing width of blink seq */
public int above_mem, below_mem;        /* Memory retained above/below screen */
public int can_goto_line;               /* Can move cursor to any line */
public int clear_bg;                    /* Clear fills with background color */
public lbool missing_cap = FALSE;       /* Some capability is missing */
public constant char *kent = NULL;      /* Keypad ENTER sequence */
public lbool term_addrs = FALSE;        /* "ti" has been sent to terminal */
public lbool full_screen = TRUE;        /* We're using all lines of terminal */

static int attrmode = AT_NORMAL; /* current attributes (AT_* bits) */
static int termcap_debug = -1;
static int no_alt_screen;       /* sc_init does not switch to alt screen */
extern int binattr;
extern lbool one_screen;
extern int shell_lines;

#if !MSDOS_COMPILER
static constant char *cheaper(constant char *t1, constant char *t2, constant char *def);
static void tmodes(constant char *inti, constant char *outti, constant char *intc, constant char *outtc, constant char **instr,
    constant char **outstr, constant char *def_instr, constant char *def_outstr, char **spp);
#endif

extern int quiet;               /* If VERY_QUIET, use visual bell for bell */
extern int no_vbell;
extern lbool no_back_scroll;
extern int no_init;
extern int no_keypad;
extern int sigs;
extern int top_scroll;
extern int quit_if_one_screen;
extern int oldbot;
extern int emouse;
extern lbool is_tty;
extern int use_color;
extern int no_paste;
extern int wscroll;
#if HILITE_SEARCH
extern int hilite_search;
#endif
#if MSDOS_COMPILER==WIN32C
extern HANDLE tty;
#else
extern int tty;
#endif

#if (HAVE_TERMIOS_H && HAVE_TERMIOS_FUNCS) || defined(TCGETA)
/*
 * Set termio flags for use by less.
 */
static void set_termio_flags(
#if HAVE_TERMIOS_H && HAVE_TERMIOS_FUNCS
	struct termios *s
#else
	struct termio *s
#endif
	)
{
	s->c_lflag &= ~(0
#ifdef ICANON
		| ICANON
#endif
#ifdef ECHO
		| ECHO
#endif
#ifdef ECHOE
		| ECHOE
#endif
#ifdef ECHOK
		| ECHOK
#endif
#ifdef ECHONL
		| ECHONL
#endif
	);

	s->c_oflag |= (0
#ifdef OPOST
		| OPOST
#endif
#ifdef ONLCR
		| ONLCR
#endif
	);

	s->c_oflag &= ~(0
#ifdef ONOEOT
		| ONOEOT
#endif
#ifdef OCRNL
		| OCRNL
#endif
#ifdef ONOCR
		| ONOCR
#endif
#ifdef ONLRET
		| ONLRET
#endif
	);

	s->c_iflag &= ~(0
#ifdef ICRNL
		| ICRNL
#endif
#ifdef INLCR
		| INLCR
#endif
	);
}
#endif

/*
 * Change terminal to "raw mode", or restore to "normal" mode.
 * "Raw mode" means 
 *      1. An outstanding read will complete on receipt of a single keystroke.
 *      2. Input is not echoed.  
 *      3. On output, \n is mapped to \r\n.
 *      4. \t is NOT expanded into spaces.
 *      5. Signal-causing characters such as ctrl-C (interrupt),
 *         etc. are NOT disabled.
 *      6. Input \r is not mapped to \n, nor vice versa.
 */
public void raw_mode(int on)
{
	static int curr_on = 0;

	if (on == curr_on)
			return;
	erase2_char = '\b'; /* in case OS doesn't know about erase2 */
#if LESSTEST
	if (is_lesstest())
	{
		/* {{ For consistent conditions when running tests. }} */
		erase_char = '\b';
		kill_char = CONTROL('U');
		werase_char = CONTROL('W');
	} else
#endif /*LESSTEST*/
#if HAVE_TERMIOS_H && HAVE_TERMIOS_FUNCS
    {
	struct termios s;
	static struct termios save_term;
	static int saved_term = 0;

	if (on) 
	{
		/*
		 * Get terminal modes.
		 */
		if (tcgetattr(tty, &s) < 0)
		{
			erase_char = '\b';
			kill_char = CONTROL('U');
			werase_char = CONTROL('W');
		} else
		{
			/*
			 * Save modes and set certain variables dependent on modes.
			 */
			if (!saved_term)
			{
				save_term = s;
				saved_term = 1;
			}
#if HAVE_OSPEED
			switch (cfgetospeed(&s))
			{
#ifdef B0
			case B0: ospeed = 0; break;
#endif
#ifdef B50
			case B50: ospeed = 1; break;
#endif
#ifdef B75
			case B75: ospeed = 2; break;
#endif
#ifdef B110
			case B110: ospeed = 3; break;
#endif
#ifdef B134
			case B134: ospeed = 4; break;
#endif
#ifdef B150
			case B150: ospeed = 5; break;
#endif
#ifdef B200
			case B200: ospeed = 6; break;
#endif
#ifdef B300
			case B300: ospeed = 7; break;
#endif
#ifdef B600
			case B600: ospeed = 8; break;
#endif
#ifdef B1200
			case B1200: ospeed = 9; break;
#endif
#ifdef B1800
			case B1800: ospeed = 10; break;
#endif
#ifdef B2400
			case B2400: ospeed = 11; break;
#endif
#ifdef B4800
			case B4800: ospeed = 12; break;
#endif
#ifdef B9600
			case B9600: ospeed = 13; break;
#endif
#ifdef EXTA
			case EXTA: ospeed = 14; break;
#endif
#ifdef EXTB
			case EXTB: ospeed = 15; break;
#endif
#ifdef B57600
			case B57600: ospeed = 16; break;
#endif
#ifdef B115200
			case B115200: ospeed = 17; break;
#endif
			default: ;
			}
#endif
			erase_char = s.c_cc[VERASE];
#ifdef VERASE2
			erase2_char = s.c_cc[VERASE2];
#endif
			kill_char = s.c_cc[VKILL];
#ifdef VWERASE
			werase_char = s.c_cc[VWERASE];
#else
			werase_char = CONTROL('W');
#endif

			/*
			 * Set the modes to the way we want them.
			 */
			set_termio_flags(&s);
			s.c_cc[VMIN] = 1;
			s.c_cc[VTIME] = 0;
#ifdef VLNEXT
			s.c_cc[VLNEXT] = 0;
#endif
#ifdef VDSUSP
			s.c_cc[VDSUSP] = 0;
#endif
#ifdef VSTOP
			s.c_cc[VSTOP] = 0;
#endif
#ifdef VSTART
			s.c_cc[VSTART] = 0;
#endif
#ifdef VDISCARD
			s.c_cc[VDISCARD] = 0;
#endif
#if MUST_SET_LINE_DISCIPLINE
			/*
			 * System's termios is broken; need to explicitly 
			 * request TERMIODISC line discipline.
			 */
			s.c_line = TERMIODISC;
#endif
		}
	} else
	{
		/*
		 * Restore saved modes.
		 */
		s = save_term;
	}
#if HAVE_FSYNC
	fsync(tty);
#endif
	tcsetattr(tty, TCSADRAIN, &s);
#if MUST_SET_LINE_DISCIPLINE
	if (!on)
	{
		/*
		 * Broken termios *ignores* any line discipline
		 * except TERMIODISC.  A different old line discipline
		 * is therefore not restored, yet.  Restore the old
		 * line discipline by hand.
		 */
		ioctl(tty, TIOCSETD, &save_term.c_line);
	}
#endif
    }
#else
#ifdef TCGETA
    {
	struct termio s;
	static struct termio save_term;
	static int saved_term = 0;

	if (on)
	{
		/*
		 * Get terminal modes.
		 */
		ioctl(tty, TCGETA, &s);

		/*
		 * Save modes and set certain variables dependent on modes.
		 */
		if (!saved_term)
		{
			save_term = s;
			saved_term = 1;
		}
#if HAVE_OSPEED
		ospeed = s.c_cflag & CBAUD;
#endif
		erase_char = s.c_cc[VERASE];
		kill_char = s.c_cc[VKILL];
#ifdef VWERASE
		werase_char = s.c_cc[VWERASE];
#else
		werase_char = CONTROL('W');
#endif

		/*
		 * Set the modes to the way we want them.
		 */
		set_termio_flags(&s);
		s.c_cc[VMIN] = 1;
		s.c_cc[VTIME] = 0;
#ifdef VSTOP
		s.c_cc[VSTOP] = 0;
#endif
#ifdef VSTART
		s.c_cc[VSTART] = 0;
#endif
	} else
	{
		/*
		 * Restore saved modes.
		 */
		s = save_term;
	}
	ioctl(tty, TCSETAW, &s);
    }
#else
#ifdef TIOCGETP
    {
	struct sgttyb s;
	static struct sgttyb save_term;
	static int saved_term = 0;

	if (on)
	{
		/*
		 * Get terminal modes.
		 */
		ioctl(tty, TIOCGETP, &s);

		/*
		 * Save modes and set certain variables dependent on modes.
		 */
		if (!saved_term)
		{
			save_term = s;
			saved_term = 1;
		}
#if HAVE_OSPEED
		ospeed = s.sg_ospeed;
#endif
		erase_char = s.sg_erase;
		kill_char = s.sg_kill;
		werase_char = CONTROL('W');

		/*
		 * Set the modes to the way we want them.
		 */
		s.sg_flags |= CBREAK;
		s.sg_flags &= ~(ECHO);
	} else
	{
		/*
		 * Restore saved modes.
		 */
		s = save_term;
	}
	ioctl(tty, TIOCSETN, &s);
    }
#else
#ifdef _OSK
    {
	struct sgbuf s;
	static struct sgbuf save_term;
	static int saved_term = 0;

	if (on)
	{
		/*
		 * Get terminal modes.
		 */
		_gs_opt(tty, &s);

		/*
		 * Save modes and set certain variables dependent on modes.
		 */
		if (!saved_term)
		{
			save_term = s;
			saved_term = 1;
		}
		erase_char = s.sg_bspch;
		kill_char = s.sg_dlnch;
		werase_char = CONTROL('W');

		/*
		 * Set the modes to the way we want them.
		 */
		s.sg_echo = 0;
		s.sg_eofch = 0;
		s.sg_pause = 0;
		s.sg_psch = 0;
	} else
	{
		/*
		 * Restore saved modes.
		 */
		s = save_term;
	}
	_ss_opt(tty, &s);
    }
#else
	/* MS-DOS, Windows, or OS2 */
#if OS2
	/* OS2 */
	LSIGNAL(SIGINT, SIG_IGN);
#endif
	erase_char = '\b';
#if MSDOS_COMPILER==DJGPPC
	kill_char = CONTROL('U');
	/*
	 * So that when we shell out or run another program, its
	 * stdin is in cooked mode.  We do not switch stdin to binary 
	 * mode if fd0 is zero, since that means we were called before
	 * tty was reopened in open_getchr, in which case we would be
	 * changing the original stdin device outside less.
	 */
	if (fd0 != 0)
		setmode(0, on ? O_BINARY : O_TEXT);
#else
	kill_char = ESC;
#endif
	werase_char = CONTROL('W');
#endif
#endif
#endif
#endif
	curr_on = on;
}

#if !MSDOS_COMPILER

/*
 * Some glue to prevent calling termcap functions if tgetent() failed.
 */
static int hardcopy;

static constant char * ltget_env(constant char *tiname, constant char *tcname)
{
	char envname[64];
	constant char *s;

	if (termcap_debug)
	{
		struct env { struct env *next; char *name; char *value; };
		constant char *capname = tcname != NULL ? tcname : tiname;
		static struct env *envs = NULL;
		struct env *p;
		for (p = envs;  p != NULL;  p = p->next)
			if (strcmp(p->name, capname) == 0)
				return p->value;
		p = (struct env *) ecalloc(1, sizeof(struct env));
		p->name = save(capname);
		p->value = (char *) ecalloc(strlen(capname)+3, sizeof(char));
		sprintf(p->value, "<%s>", capname);
		p->next = envs;
		envs = p;
		return p->value;
	}
	if (tiname != NULL)
	{
		SNPRINTF1(envname, sizeof(envname), "LESS_TERMINFO_%s", tiname);
		s = lgetenv(envname);
		if (!isnullenv(s))
			return s;
	}
	if (tcname != NULL)
	{
		SNPRINTF1(envname, sizeof(envname), "LESS_TERMCAP_%s", tcname);
		s = lgetenv(envname);
		if (!isnullenv(s))
			return s;
	}
	return NULL;
}

static int ltgetflag(constant char *tiname, constant char *tcname)
{
	constant char *s;

	if ((s = ltget_env(tiname, tcname)) != NULL)
		return (*s != '\0' && *s != '0');
	if (hardcopy)
		return (0);
#if USE_TERMINFO
	return tiname == NULL ? 0 : tigetflag(tiname);
#else
	return tcname == NULL ? 0 : tgetflag(tcname);
#endif
}

static int ltgetnum(constant char *tiname, constant char *tcname)
{
	constant char *s;

	if ((s = ltget_env(tiname, tcname)) != NULL)
		return (atoi(s));
	if (hardcopy)
		return (-1);
#if USE_TERMINFO
	return tiname == NULL ? -1 : tigetnum(tiname);
#else
	return tcname == NULL ? -1 : tgetnum(tcname);
#endif
}

static constant char * ltgetstr(constant char *tiname, constant char *tcname, char **pp)
{
	constant char *s;

	if ((s = ltget_env(tiname, tcname)) != NULL)
		return (s);
	if (hardcopy)
		return (NULL);
#if USE_TERMINFO
	if (tiname == NULL)
		return (NULL);
	s = tigetstr(tiname);
	if (s == (constant char *)-1)
		s = NULL;
	return (s);
#else
	if (tcname == NULL)
		return (NULL);
	return tgetstr(tcname, pp);
#endif
}
#endif /* MSDOS_COMPILER */

/*
 * Get size of the output screen.
 */
public void scrsize(void)
{
	constant char *s;
	int sys_height;
	int sys_width;
#if !MSDOS_COMPILER
	int n;
#endif

#define DEF_SC_WIDTH    80
#if MSDOS_COMPILER
#define DEF_SC_HEIGHT   25
#else
#define DEF_SC_HEIGHT   24
#endif

	sys_width = sys_height = 0;

#if LESSTEST
	if (0) /* can't use is_lesstest(): ttyin_name may not be set by scan_option yet */
#endif /*LESSTEST*/
	{
#if MSDOS_COMPILER==MSOFTC
	{
		struct videoconfig w;
		_getvideoconfig(&w);
		sys_height = w.numtextrows;
		sys_width = w.numtextcols;
	}
#else
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
	{
		struct text_info w;
		gettextinfo(&w);
		sys_height = w.screenheight;
		sys_width = w.screenwidth;
	}
#else
#if MSDOS_COMPILER==WIN32C
	{
		CONSOLE_SCREEN_BUFFER_INFO scr;
		GetConsoleScreenBufferInfo(con_out, &scr);
		sys_height = scr.srWindow.Bottom - scr.srWindow.Top + 1;
		sys_width = scr.srWindow.Right - scr.srWindow.Left + 1;
	}
#else
#if OS2
	{
		int s[2];
		_scrsize(s);
		sys_width = s[0];
		sys_height = s[1];
		/*
		 * When using terminal emulators for XFree86/OS2, the
		 * _scrsize function does not work well.
		 * Call the scrsize.exe program to get the window size.
		 */
		windowid = getenv("WINDOWID");
		if (windowid != NULL)
		{
			FILE *fd = popen("scrsize", "rt");
			if (fd != NULL)
			{
				int w, h;
				fscanf(fd, "%i %i", &w, &h);
				if (w > 0 && h > 0)
				{
					sys_width = w;
					sys_height = h;
				}
				pclose(fd);
			}
		}
	}
#else
#ifdef TIOCGWINSZ
	{
		struct winsize w;
		if (ioctl(2, TIOCGWINSZ, &w) == 0 || ioctl(1, TIOCGWINSZ, &w) == 0)
		{
			if (w.ws_row > 0)
				sys_height = w.ws_row;
			if (w.ws_col > 0)
				sys_width = w.ws_col;
		}
	}
#else
#ifdef WIOCGETD
	{
		struct uwdata w;
		if (ioctl(2, WIOCGETD, &w) == 0 || ioctl(1, WIOCGETD, &w) == 0)
		{
			if (w.uw_height > 0)
				sys_height = w.uw_height / w.uw_vs;
			if (w.uw_width > 0)
				sys_width = w.uw_width / w.uw_hs;
		}
	}
#endif
#endif
#endif
#endif
#endif
#endif
	}

	if (sys_height > 0)
		sc_height = sys_height;
	else if ((s = lgetenv("LINES")) != NULL)
		sc_height = atoi(s);
#if !MSDOS_COMPILER
	else if ((n = ltgetnum("lines", "li")) > 0)
		sc_height = n;
#endif
	if ((s = lgetenv("LESS_LINES")) != NULL)
	{
		int height = atoi(s);
		sc_height = (height < 0) ? sc_height + height : height;
		full_screen = FALSE;
	}
	if (sc_height <= 0)
		sc_height = DEF_SC_HEIGHT;

	if (sys_width > 0)
		sc_width = sys_width;
	else if ((s = lgetenv("COLUMNS")) != NULL)
		sc_width = atoi(s);
#if !MSDOS_COMPILER
	else if ((n = ltgetnum("cols", "co")) > 0)
		sc_width = n;
#endif
	if ((s = lgetenv("LESS_COLUMNS")) != NULL)
	{
		int width = atoi(s);
		sc_width = (width < 0) ? sc_width + width : width;
	}
	if (sc_width <= 0)
		sc_width = DEF_SC_WIDTH;
	screen_size_changed();
}

/*
 * Recalculate things that depend on the screen size.
 */
public void screen_size_changed(void)
{
	constant char *env = lgetenv("LESS_SHELL_LINES");
	shell_lines = isnullenv(env) ? 1 : atoi(env);
	if (shell_lines >= sc_height)
		shell_lines = sc_height - 1;
	wscroll = (sc_height + 1) / 2;
	calc_jump_sline();
	calc_shift_count();
	calc_match_shift();
}

#if MSDOS_COMPILER==MSOFTC
/*
 * Figure out how many empty loops it takes to delay a millisecond.
 */
static void get_clock(void)
{
	clock_t start;
	
	/*
	 * Get synchronized at the start of a tick.
	 */
	start = clock();
	while (clock() == start)
		;
	/*
	 * Now count loops till the next tick.
	 */
	start = clock();
	msec_loops = 0;
	while (clock() == start)
		msec_loops++;
	/*
	 * Convert from (loops per clock) to (loops per millisecond).
	 */
	msec_loops *= CLOCKS_PER_SEC;
	msec_loops /= 1000;
}

/*
 * Delay for a specified number of milliseconds.
 */
static void delay(int msec)
{
	long i;
	
	while (msec-- > 0)
	{
		for (i = 0;  i < msec_loops;  i++)
			(void) clock();
	}
}
#endif

/*
 * Return the characters actually input by a "special" key.
 */
public constant char * special_key_str(int key)
{
	static char tbuf[40];
	constant char *s;
#if MSDOS_COMPILER || OS2
	static char k_right[]           = { '\340', PCK_RIGHT, 0 };
	static char k_left[]            = { '\340', PCK_LEFT, 0  };
	static char k_ctl_right[]       = { '\340', PCK_CTL_RIGHT, 0  };
	static char k_ctl_left[]        = { '\340', PCK_CTL_LEFT, 0  };
	static char k_shift_right[]     = { '\340', PCK_SHIFT_RIGHT, 0  };
	static char k_shift_left[]      = { '\340', PCK_SHIFT_LEFT, 0  };
	static char k_insert[]          = { '\340', PCK_INSERT, 0  };
	static char k_delete[]          = { '\340', PCK_DELETE, 0  };
	static char k_ctl_delete[]      = { '\340', PCK_CTL_DELETE, 0  };
	static char k_ctl_backspace[]   = { '\177', 0 };
	static char k_backspace[]       = { '\b', 0 };
	static char k_home[]            = { '\340', PCK_HOME, 0 };
	static char k_end[]             = { '\340', PCK_END, 0 };
	static char k_up[]              = { '\340', PCK_UP, 0 };
	static char k_down[]            = { '\340', PCK_DOWN, 0 };
	static char k_backtab[]         = { '\340', PCK_SHIFT_TAB, 0 };
	static char k_pagedown[]        = { '\340', PCK_PAGEDOWN, 0 };
	static char k_pageup[]          = { '\340', PCK_PAGEUP, 0 };
	static char k_ctl_home[]        = { '\340', PCK_CTL_HOME, 0 };
	static char k_ctl_end[]         = { '\340', PCK_CTL_END, 0 };
	static char k_shift_home[]      = { '\340', PCK_SHIFT_HOME, 0 };
	static char k_shift_end[]       = { '\340', PCK_SHIFT_END, 0 };
	static char k_f1[]              = { '\340', PCK_F1, 0 };
#endif
#if !MSDOS_COMPILER
	char *sp = tbuf;
#endif

	switch (key)
	{
#if OS2
	/*
	 * If windowid is not NULL, assume less is executed in 
	 * the XFree86 environment.
	 */
	case SK_RIGHT_ARROW:
		s = windowid ? ltgetstr("kcuf1", "kr", &sp) : k_right;
		break;
	case SK_LEFT_ARROW:
		s = windowid ? ltgetstr("kcub1", "kl", &sp) : k_left;
		break;
	case SK_UP_ARROW:
		s = windowid ? ltgetstr("kcuu1", "ku", &sp) : k_up;
		break;
	case SK_DOWN_ARROW:
		s = windowid ? ltgetstr("kcud1", "kd", &sp) : k_down;
		break;
	case SK_PAGE_UP:
		s = windowid ? ltgetstr("kpp", "kP", &sp) : k_pageup;
		break;
	case SK_PAGE_DOWN:
		s = windowid ? ltgetstr("knp", "kN", &sp) : k_pagedown;
		break;
	case SK_HOME:
		s = windowid ? ltgetstr("khome", "kh", &sp) : k_home;
		break;
	case SK_END:
		s = windowid ? ltgetstr("kend", "@7", &sp) : k_end;
		break;
	case SK_F1:
		s = windowid ? ltgetstr("kf1", "k1", &sp) : k_f1;
		break;
	case SK_DELETE:
		s = windowid ? ltgetstr("kdch1", "kD", &sp) : k_delete;
		if (s == NULL)
		{
				tbuf[0] = '\177';
				tbuf[1] = '\0';
				s = tbuf;
		}
		break;
#endif
#if MSDOS_COMPILER
	case SK_RIGHT_ARROW:
		s = k_right;
		break;
	case SK_LEFT_ARROW:
		s = k_left;
		break;
	case SK_UP_ARROW:
		s = k_up;
		break;
	case SK_DOWN_ARROW:
		s = k_down;
		break;
	case SK_PAGE_UP:
		s = k_pageup;
		break;
	case SK_PAGE_DOWN:
		s = k_pagedown;
		break;
	case SK_HOME:
		s = k_home;
		break;
	case SK_END:
		s = k_end;
		break;
	case SK_DELETE:
		s = k_delete;
		break;
#endif
#if MSDOS_COMPILER || OS2
	case SK_INSERT:
		s = k_insert;
		break;
	case SK_CTL_LEFT_ARROW:
		s = k_ctl_left;
		break;
	case SK_CTL_RIGHT_ARROW:
		s = k_ctl_right;
		break;
	case SK_SHIFT_LEFT_ARROW:
		s = k_shift_left;
		break;
	case SK_SHIFT_RIGHT_ARROW:
		s = k_shift_right;
		break;
	case SK_CTL_BACKSPACE:
		s = k_ctl_backspace;
		break;
	case SK_CTL_DELETE:
		s = k_ctl_delete;
		break;
	case SK_BACKSPACE:
		s = k_backspace;
		break;
	case SK_F1:
		s = k_f1;
		break;
	case SK_BACKTAB:
		s = k_backtab;
		break;
	case SK_SHIFT_HOME:
		s = k_shift_home;
		break;
	case SK_CTL_HOME:
		s = k_ctl_home;
		break;
	case SK_SHIFT_END:
		s = k_shift_end;
		break;
	case SK_CTL_END:
		s = k_ctl_end;
		break;
#else
	case SK_RIGHT_ARROW:
		s = ltgetstr("kcuf1", "kr", &sp);
		break;
	case SK_LEFT_ARROW:
		s = ltgetstr("kcub1", "kl", &sp);
		break;
	case SK_UP_ARROW:
		s = ltgetstr("kcuu1", "ku", &sp);
		break;
	case SK_DOWN_ARROW:
		s = ltgetstr("kcud1", "kd", &sp);
		break;
	case SK_PAGE_UP:
		s = ltgetstr("kpp", "kP", &sp);
		break;
	case SK_PAGE_DOWN:
		s = ltgetstr("knp", "kN", &sp);
		break;
	case SK_HOME:
		s = ltgetstr("khome", "kh", &sp);
		break;
	case SK_SHIFT_HOME:
		s = ltgetstr("kHOM", "#2", &sp);
		break;
	case SK_CTL_HOME:
		s = ltgetstr("kHOM5", NULL, &sp);
		break;
	case SK_END:
		s = ltgetstr("kend", "@7", &sp);
		break;
	case SK_SHIFT_END:
		s = ltgetstr("kEND", "#7", &sp);
		break;
	case SK_CTL_END:
		s = ltgetstr("kEND5", NULL, &sp);
		break;
	case SK_INSERT:
		s = ltgetstr("kich1", "kI", &sp);
		break;
	case SK_BACKTAB:
		s = ltgetstr("kcbt", "kB", &sp);
		break;
	case SK_SHIFT_RIGHT_ARROW:
		s = ltgetstr("kRIT", NULL, &sp);
		break;
	case SK_SHIFT_LEFT_ARROW:
		s = ltgetstr("kLFT", NULL, &sp);
		break;
	case SK_CTL_RIGHT_ARROW:
		s = ltgetstr("kRIT5", NULL, &sp);
		break;
	case SK_CTL_LEFT_ARROW:
		s = ltgetstr("kLFT5", NULL, &sp);
		break;
	case SK_F1:
		s = ltgetstr("kf1", "k1", &sp);
		break;
	case SK_PAD_UL:
		s = ltgetstr("ka1", "K1", &sp);
		break;
	case SK_PAD_U:
		s = ltgetstr("ka2", NULL, &sp);
		break;
	case SK_PAD_UR:
		s = ltgetstr("ka3", "K3", &sp);
		break;
	case SK_PAD_L:
		s = ltgetstr("kb1", NULL, &sp);
		break;
	case SK_PAD_CENTER:
		s = ltgetstr("kb2", "K2", &sp);
		break;
	case SK_PAD_R:
		s = ltgetstr("kb3", NULL, &sp);
		break;
	case SK_PAD_DL:
		s = ltgetstr("kc1", "K4", &sp);
		break;
	case SK_PAD_D:
		s = ltgetstr("kc2", NULL, &sp);
		break;
	case SK_PAD_DR:
		s = ltgetstr("kc3", "K5", &sp);
		break;
	case SK_PAD_STAR:
		s = ltgetstr("kpMUL", NULL, &sp);
		break;
	case SK_PAD_SLASH:
		s = ltgetstr("kpDIV", NULL, &sp);
		break;
	case SK_PAD_DASH:
		s = ltgetstr("kpSUB", NULL, &sp);
		break;
	case SK_PAD_PLUS:
		s = ltgetstr("kpADD", NULL, &sp);
		break;
	case SK_PAD_DOT:
		s = ltgetstr("kpDOT", NULL, &sp);
		break;
	case SK_PAD_COMMA:
		s = ltgetstr("kpCMA", NULL, &sp);
		break;
	case SK_PAD_ZERO:
		s = ltgetstr("kpZRO", NULL, &sp);
		break;
	case SK_DELETE:
		s = ltgetstr("kdch1", "kD", &sp);
		if (s == NULL)
		{
				tbuf[0] = '\177';
				tbuf[1] = '\0';
				s = tbuf;
		}
		break;
	case SK_BACKSPACE:
		s = ltgetstr("kbs", "kb", &sp);
		if (s == NULL)
		{
				tbuf[0] = '\b';
				tbuf[1] = '\0';
				s = tbuf;
		}
		break;
#endif
	case SK_CONTROL_K:
		tbuf[0] = CONTROL('K');
		tbuf[1] = '\0';
		s = tbuf;
		break;
	default:
		return (NULL);
	}
	if (s != NULL && *s == '\0')
		s = NULL;
	return (s);
}

#if !MSDOS_COMPILER
static constant char *ltgoto(constant char *cap, int col, int line)
{
#if USE_TERMINFO
	return LTPARM2(cap, line, col);
#else
	return tgoto(cap, col, line);
#endif
}
#endif /* MSDOS_COMPILER */

#if MSDOS_COMPILER
public void init_win_colors(void)
{
	if (nm_fg_color == CV_ERROR || nm_fg_color == CV_NOCHANGE) nm_fg_color = sy_fg_color;
	if (nm_bg_color == CV_ERROR || nm_bg_color == CV_NOCHANGE) nm_bg_color = sy_bg_color;
	if (bo_fg_color == CV_NOCHANGE) bo_fg_color = sy_fg_color; else if (bo_fg_color == CV_ERROR) bo_fg_color = sy_fg_color | 8;
	if (bo_bg_color == CV_NOCHANGE) bo_bg_color = sy_bg_color; else if (bo_bg_color == CV_ERROR) bo_bg_color = sy_bg_color;
	if (ul_fg_color == CV_NOCHANGE) ul_fg_color = sy_fg_color; else if (ul_fg_color == CV_ERROR) ul_fg_color = (sy_bg_color == 3 || sy_bg_color == 11) ? 0 : 11;
	if (ul_bg_color == CV_NOCHANGE) ul_bg_color = sy_bg_color; else if (ul_bg_color == CV_ERROR) ul_bg_color = sy_bg_color;
	if (so_fg_color == CV_NOCHANGE) so_fg_color = sy_fg_color; else if (so_fg_color == CV_ERROR) so_fg_color = sy_bg_color;
	if (so_bg_color == CV_NOCHANGE) so_bg_color = sy_bg_color; else if (so_bg_color == CV_ERROR) so_bg_color = sy_fg_color;
	if (bl_fg_color == CV_NOCHANGE) bl_fg_color = sy_fg_color; else if (bl_fg_color == CV_ERROR) bl_fg_color = ul_bg_color;
	if (bl_bg_color == CV_NOCHANGE) bl_bg_color = sy_bg_color; else if (bl_bg_color == CV_ERROR) bl_bg_color = ul_fg_color;
	nm_fg_color |= nm_attr;
	bo_fg_color |= bo_attr;
	ul_fg_color |= ul_attr;
	so_fg_color |= so_attr;
	bl_fg_color |= bl_attr;
}
#endif /* MSDOS_COMPILER */

/*
 * Get terminal capabilities via termcap.
 */
public void get_term()
{
	termcap_debug = !isnullenv(lgetenv("LESS_TERMCAP_DEBUG"));
#if MSDOS_COMPILER
	auto_wrap = 1;
	defer_wrap = 0;
	can_goto_line = 1;
	clear_bg = 1;
	/*
	 * Set up default colors.
	 * The xx_s_width and xx_e_width vars are already initialized to 0.
	 */
#if MSDOS_COMPILER==MSOFTC
	sy_bg_color = _getbkcolor();
	sy_fg_color = _gettextcolor();
	get_clock();
#else
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
    {
	struct text_info w;
	gettextinfo(&w);
	sy_bg_color = (w.attribute >> 4) & 0x0F;
	sy_fg_color = (w.attribute >> 0) & 0x0F;
    }
#else
#if MSDOS_COMPILER==WIN32C
    {
	CONSOLE_SCREEN_BUFFER_INFO scr;

	con_out_save = con_out = GetStdHandle(STD_OUTPUT_HANDLE);
	/*
	 * Always open stdin in binary. Note this *must* be done
	 * before any file operations have been done on fd0.
	 */
	SET_BINARY(0);
	GetConsoleMode(con_out, &init_console_output_mode);
	GetConsoleScreenBufferInfo(con_out, &scr);
	curr_attr = scr.wAttributes;
	sy_bg_color = (curr_attr & BG_COLORS) >> 4; /* normalize */
	sy_fg_color = curr_attr & FG_COLORS;
    }
#endif
#endif
#endif
	init_win_colors();

	/*
	 * Get size of the screen.
	 */
	scrsize();
	pos_init();

#else /* !MSDOS_COMPILER */
{
	constant char *t1;
	constant char *t2;
	constant char *term;
	char *sp;
	/*
	 * Some termcap libraries assume termbuf is static
	 * (accessible after tgetent returns).
	 */
#if !USE_TERMINFO
	static char termbuf[TERMBUF_SIZE];
#endif
	static char sbuf[TERMSBUF_SIZE];

#if OS2
	/*
	 * Make sure the termcap database is available.
	 */
	constant char *cp = lgetenv("TERMCAP");
	if (isnullenv(cp))
	{
		char *termcap;
		if ((sp = homefile("termcap.dat")) != NULL)
		{
			termcap = (char *) ecalloc(strlen(sp)+9, sizeof(char));
			sprintf(termcap, "TERMCAP=%s", sp);
			free(sp);
			putenv(termcap);
		}
	}
#endif
	/*
	 * Find out what kind of terminal this is.
	 */
	if ((term = lgetenv("TERM")) == NULL && (term = getenv("TERM")) == NULL)
		term = DEFAULT_TERM;
	hardcopy = 0;
#if USE_TERMINFO
	if (cur_term != NULL)
		del_curterm(cur_term);
	if (setupterm(term, -1, NULL) != OK)
		hardcopy = 1;
#else
	if (tgetent(termbuf, term) != TGETENT_OK)
		hardcopy = 1;
#endif
	if (!hardcopy && ltgetflag("hc", "hc"))
		hardcopy = 1;

	/*
	 * Get size of the screen.
	 */
	scrsize();
	pos_init();

	auto_wrap = ltgetflag("am", "am");
	defer_wrap = ltgetflag("xenl", "xn");
	above_mem = ltgetflag("da", "da");
	below_mem = ltgetflag("db", "db");
	clear_bg = ltgetflag("bce", "ut");
	no_alt_screen = ltgetflag("nrrmc", "NR");

	/*
	 * Assumes termcap variable "sg" is the printing width of:
	 * the standout sequence, the end standout sequence,
	 * the underline sequence, the end underline sequence,
	 * the boldface sequence, and the end boldface sequence.
	 */
	if ((so_s_width = ltgetnum("xmc", "sg")) < 0)
		so_s_width = 0;
	so_e_width = so_s_width;

	bo_s_width = bo_e_width = so_s_width;
	ul_s_width = ul_e_width = so_s_width;
	bl_s_width = bl_e_width = so_s_width;

#if HILITE_SEARCH
	if (so_s_width > 0 || so_e_width > 0)
		/*
		 * Disable highlighting by default on magic cookie terminals.
		 * Turning on highlighting might change the displayed width
		 * of a line, causing the display to get messed up.
		 * The user can turn it back on with -g, 
		 * but she won't like the results.
		 */
		hilite_search = 0;
#endif

	/*
	 * Get various string-valued capabilities.
	 */
	sp = sbuf;

#if HAVE_OSPEED
	sc_pad = ltgetstr("pad", "pc", &sp);
	if (sc_pad != NULL)
		PC = *sc_pad;
#endif

	sc_s_keypad = ltgetstr("smkx", "ks", &sp);
	if (sc_s_keypad == NULL)
		sc_s_keypad = "";
	sc_e_keypad = ltgetstr("rmkx", "ke", &sp);
	if (sc_e_keypad == NULL)
		sc_e_keypad = "";
	kent = ltgetstr("kent", "@8", &sp);

	sc_s_mousecap = ltgetstr("MOUSE_START", "MOUSE_START", &sp);
	if (sc_s_mousecap == NULL)
		sc_s_mousecap = ESCS "[?1000h" ESCS "[?1002h" ESCS "[?1006h";
	sc_e_mousecap = ltgetstr("MOUSE_END", "MOUSE_END", &sp);
	if (sc_e_mousecap == NULL)
		sc_e_mousecap = ESCS "[?1006l" ESCS "[?1002l" ESCS "[?1000l";

	sc_s_bracketed_paste = ltgetstr("BRACKETED_PASTE_START", "BRACKETED_PASTE_START", &sp);
	if (sc_s_bracketed_paste == NULL)
		sc_s_bracketed_paste = ESCS"[?2004h";
	sc_e_bracketed_paste = ltgetstr("BRACKETED_PASTE_END", "BRACKETED_PASTE_END", &sp);
	if (sc_e_bracketed_paste == NULL)
		sc_e_bracketed_paste = ESCS"[?2004l";

	sc_suspend = ltgetstr("SUSPEND", "SUSPEND", &sp);
	if (sc_suspend == NULL)
		sc_suspend = "";
	sc_resume = ltgetstr("RESUME", "RESUME", &sp);
	if (sc_resume == NULL)
		sc_resume = "";

	sc_init = ltgetstr("smcup", "ti", &sp);
	if (sc_init == NULL)
		sc_init = "";

	sc_deinit= ltgetstr("rmcup", "te", &sp);
	if (sc_deinit == NULL)
		sc_deinit = "";

	sc_eol_clear = ltgetstr("el", "ce", &sp);
	if (sc_eol_clear == NULL || *sc_eol_clear == '\0')
	{
		missing_cap = TRUE;
		sc_eol_clear = "";
	}

	sc_eos_clear = ltgetstr("ed", "cd", &sp);
	if (below_mem && (sc_eos_clear == NULL || *sc_eos_clear == '\0'))
	{
		missing_cap = TRUE;
		sc_eos_clear = "";
	}

	sc_clear = ltgetstr("clear", "cl", &sp);
	if (sc_clear == NULL || *sc_clear == '\0')
	{
		missing_cap = TRUE;
		sc_clear = "\n\n";
	}

	sc_move = ltgetstr("cup", "cm", &sp);
	if (sc_move == NULL || *sc_move == '\0')
	{
		/*
		 * This is not an error here, because we don't 
		 * always need sc_move.
		 * We need it only if we don't have home or lower-left.
		 */
		sc_move = "";
		can_goto_line = 0;
	} else
		can_goto_line = 1;

	tmodes("smso", "rmso", "so", "se", &sc_s_in, &sc_s_out, "", "", &sp);
	tmodes("smul", "rmul", "us", "ue", &sc_u_in, &sc_u_out, sc_s_in, sc_s_out, &sp);
	tmodes("bold", "sgr0", "md", "me", &sc_b_in, &sc_b_out, sc_s_in, sc_s_out, &sp);
	tmodes("blink", "sgr0", "mb", "me", &sc_bl_in, &sc_bl_out, sc_s_in, sc_s_out, &sp);

	sc_visual_bell = ltgetstr("flash", "vb", &sp);
	if (sc_visual_bell == NULL)
		sc_visual_bell = "";

	if (ltgetflag(NULL, "bs"))
		sc_backspace = "\b";
	else
	{
		sc_backspace = ltgetstr("OTbc", "bc", &sp);
		if (sc_backspace == NULL || *sc_backspace == '\0')
			sc_backspace = "\b";
	}

	/*
	 * Choose between using "ho" and "cm" ("home" and "cursor move")
	 * to move the cursor to the upper left corner of the screen.
	 */
	t1 = ltgetstr("home", "ho", &sp);
	if (t1 == NULL)
		t1 = "";
	if (*sc_move == '\0')
		t2 = "";
	else
	{
		strcpy(sp, ltgoto(sc_move, 0, 0));
		t2 = sp;
		sp += strlen(sp) + 1;
	}
	sc_home = cheaper(t1, t2, "|\b^");

	/*
	 * Choose between using "ll" and "cm"  ("lower left" and "cursor move")
	 * to move the cursor to the lower left corner of the screen.
	 */
	t1 = ltgetstr("ll", "ll", &sp);
	if (t1 == NULL || !full_screen)
		t1 = "";
	if (*sc_move == '\0')
		t2 = "";
	else
	{
		strcpy(sp, ltgoto(sc_move, 0, sc_height-1));
		t2 = sp;
		sp += strlen(sp) + 1;
	}
	sc_lower_left = cheaper(t1, t2, "\r");

	/*
	 * Get carriage return string.
	 */
	sc_return = ltgetstr("cr", "cr", &sp);
	if (sc_return == NULL)
		sc_return = "\r";

	/*
	 * Choose between using "al" or "sr" ("add line" or "scroll reverse")
	 * to add a line at the top of the screen.
	 */
	t1 = ltgetstr("ill", "al", &sp);
	if (t1 == NULL)
		t1 = "";
	t2 = ltgetstr("ri", "sr", &sp);
	if (t2 == NULL)
		t2 = "";
	if (*t1 == '\0' && *t2 == '\0')
		sc_addline = "";
	else if (above_mem)
		sc_addline = t1;
	else
		sc_addline = cheaper(t1, t2, "");
	if (*sc_addline == '\0')
	{
		/*
		 * Force repaint on any backward movement.
		 */
		no_back_scroll = TRUE;
	}
}
#endif /* MSDOS_COMPILER */
}

#if !MSDOS_COMPILER
/*
 * Return the cost of displaying a termcap string.
 * We use the trick of calling tputs, but as a char printing function
 * we give it inc_costcount, which just increments "costcount".
 * This tells us how many chars would be printed by using this string.
 */
static int costcount;

/*ARGSUSED*/
static int inc_costcount(int c)
{
	costcount++;
	return (c);
}

static int cost(constant char *t)
{
	costcount = 0;
	tputs(t, sc_height, inc_costcount);
	return (costcount);
}

/*
 * Return the "best" of the two given termcap strings.
 * The best, if both exist, is the one with the lower 
 * cost (see cost() function).
 */
static constant char * cheaper(constant char *t1, constant char *t2, constant char *def)
{
	if (*t1 == '\0' && *t2 == '\0')
	{
		missing_cap = TRUE;
		return (def);
	}
	if (*t1 == '\0')
		return (t2);
	if (*t2 == '\0')
		return (t1);
	if (cost(t1) < cost(t2))
		return (t1);
	return (t2);
}

static void tmodes(constant char *inti, constant char *outti, constant char *intc, constant char *outtc, constant char **instr, constant char **outstr, constant char *def_instr, constant char *def_outstr, char **spp)
{
	*instr = ltgetstr(inti, intc, spp);
	if (*instr == NULL)
	{
		/* Use defaults. */
		*instr = def_instr;
		*outstr = def_outstr;
		return;
	}

	*outstr = ltgetstr(outti, outtc, spp);
	if (*outstr == NULL)
		/* No specific out capability; use "me". */
		*outstr = ltgetstr("sgr0", "me", spp);
	if (*outstr == NULL)
		/* Don't even have "me"; use a null string. */
		*outstr = "";
}

#endif /* MSDOS_COMPILER */


/*
 * Below are the functions which perform all the 
 * terminal-specific screen manipulation.
 */


#if MSDOS_COMPILER

#if MSDOS_COMPILER==WIN32C
static void _settextposition(int row, int col)
{
	COORD cpos;
	CONSOLE_SCREEN_BUFFER_INFO csbi;

	GetConsoleScreenBufferInfo(con_out, &csbi);
	cpos.X = csbi.srWindow.Left + (col - 1);
	cpos.Y = csbi.srWindow.Top + (row - 1);
	SetConsoleCursorPosition(con_out, cpos);
}
#endif

/*
 * Initialize the screen to the correct color at startup.
 */
static void initcolor(void)
{
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
	intensevideo();
#endif
	SETCOLORS(nm_fg_color, nm_bg_color);
#if 0
	/*
	 * This clears the screen at startup.  This is different from
	 * the behavior of other versions of less.  Disable it for now.
	 */
	char *blanks;
	int row;
	int col;
	
	/*
	 * Create a complete, blank screen using "normal" colors.
	 */
	SETCOLORS(nm_fg_color, nm_bg_color);
	blanks = (char *) ecalloc(width+1, sizeof(char));
	for (col = 0;  col < sc_width;  col++)
		blanks[col] = ' ';
	blanks[sc_width] = '\0';
	for (row = 0;  row < sc_height;  row++)
		_outtext(blanks);
	free(blanks);
#endif
}
#endif

#if MSDOS_COMPILER==WIN32C

/*
 * Enable virtual terminal processing, if available.
 */
static void win32_init_vt_term(void)
{
	if (vt_enabled == 0 || (vt_enabled == 1 && con_out == con_out_ours))
		return;  /* already initialized */

	/* don't care about the initial mode, and win VT hard-enables am+xn */
	vt_enabled = SetConsoleMode(con_out, ENABLE_PROCESSED_OUTPUT |
	                                     ENABLE_VIRTUAL_TERMINAL_PROCESSING |
	                                     ENABLE_WRAP_AT_EOL_OUTPUT);
	if (vt_enabled)
	{
		auto_wrap = 1;
		defer_wrap = 1;
	}
}

static void win32_deinit_vt_term(void)
{
	if (vt_enabled == 1 && con_out == con_out_save)
		SetConsoleMode(con_out, init_console_output_mode);
}

/*
 * Termcap-like init with a private win32 console.
 */
static void win32_init_term(void)
{
	CONSOLE_SCREEN_BUFFER_INFO scr;
	COORD size;

	if (con_out_save == INVALID_HANDLE_VALUE)
		return;

	GetConsoleScreenBufferInfo(con_out_save, &scr);

	if (con_out_ours == INVALID_HANDLE_VALUE)
	{
		/*
		 * Create our own screen buffer, so that we
		 * may restore the original when done.
		 */
		con_out_ours = CreateConsoleScreenBuffer(
			GENERIC_WRITE | GENERIC_READ,
			FILE_SHARE_WRITE | FILE_SHARE_READ,
			(LPSECURITY_ATTRIBUTES) NULL,
			CONSOLE_TEXTMODE_BUFFER,
			(LPVOID) NULL);

		/*
		 * We don't care about the initial state. We need processed
		 * output without anything else (no wrap at EOL, no VT,
		 * no disabled auto-return).
		 */
		if (SetConsoleMode(con_out_ours, ENABLE_PROCESSED_OUTPUT))
			auto_wrap = 0;
	}

	size.X = scr.srWindow.Right - scr.srWindow.Left + 1;
	size.Y = scr.srWindow.Bottom - scr.srWindow.Top + 1;
	SetConsoleScreenBufferSize(con_out_ours, size);
	SetConsoleActiveScreenBuffer(con_out_ours);
	con_out = con_out_ours;
}

/*
 * Restore the startup console.
 */
static void win32_deinit_term(void)
{
	if (con_out_save == INVALID_HANDLE_VALUE)
		return;
	if (quitting)
		(void) CloseHandle(con_out_ours);
	SetConsoleActiveScreenBuffer(con_out_save);
	con_out = con_out_save;
}

#endif

#if !MSDOS_COMPILER
static void do_tputs(constant char *str, int affcnt, int (*f_putc)(int))
{
#if LESSTEST
	if (is_lesstest() && f_putc == putchr)
		putstr(str);
	else
#endif /*LESSTEST*/
		tputs(str, affcnt, f_putc);
}

/*
 * Like tputs but we handle $<...> delay strings here because
 * some implementations of tputs don't perform delays correctly.
 */
static void ltputs(constant char *str, int affcnt, int (*f_putc)(int))
{
	while (str != NULL && *str != '\0')
	{
		constant char *obrac = strstr(str, "$<");
		if (obrac != NULL)
		{
			char str2[64];
			size_t slen = ptr_diff(obrac, str);
			if (slen < sizeof(str2))
			{
				int delay;
				/* Output first part of string (before "$<"). */
				memcpy(str2, str, slen);
				str2[slen] = '\0';
				do_tputs(str2, affcnt, f_putc);
				str += slen + 2;
				/* Perform the delay. */
				delay = lstrtoic(str, &str, 10);
				if (*str == '*')
					if (ckd_mul(&delay, delay, affcnt))
						delay = INT_MAX;
				flush();
				sleep_ms(delay);
				/* Skip past closing ">" at end of delay string. */
				str = strstr(str, ">");
				if (str != NULL)
					str++;
				continue;
			}
		}
		/* Pass the rest of the string to tputs and we're done. */
		do_tputs(str, affcnt, f_putc);
		break;
	}
}
#endif /* MSDOS_COMPILER */

/*
 * Configure the terminal so mouse clicks and wheel moves 
 * produce input to less.
 */
public void init_mouse(void)
{
#if !MSDOS_COMPILER
	ltputs(sc_s_mousecap, sc_height, putchr);
#else
#if MSDOS_COMPILER==WIN32C
	curr_console_input_mode = mouse_console_input_mode;
	SetConsoleMode(tty, curr_console_input_mode);
#endif
#endif
}

/*
 * Configure the terminal so mouse clicks and wheel moves
 * are handled by the system (so text can be selected, etc).
 */
public void deinit_mouse(void)
{
#if !MSDOS_COMPILER
	ltputs(sc_e_mousecap, sc_height, putchr);
#else
#if MSDOS_COMPILER==WIN32C
	curr_console_input_mode = base_console_input_mode;
	SetConsoleMode(tty, curr_console_input_mode);
#endif
#endif
}

/*
 * Suspend screen updates.
 */
public void suspend_screen(void)
{
#if !MSDOS_COMPILER
	ltputs(sc_suspend, 1, putchr);
#endif
}

/*
 * Resume screen updates.
 */
public void resume_screen(void)
{
#if !MSDOS_COMPILER
	ltputs(sc_resume, 1, putchr);
#endif
}

/*
 * Initialize terminal
 */
public void term_init(void)
{
	if (term_init_done)
		return;
	term_init_done = term_init_ever = TRUE;
	clear_bot_if_needed();
#if !MSDOS_COMPILER
	if (!(quit_if_one_screen && one_screen))
	{
		if (!no_init)
		{
			ltputs(sc_init, sc_height, putchr);
			/*
			 * Some terminals leave the cursor unmoved when switching 
			 * to the alt screen. To avoid having the text appear at
			 * a seemingly random line on the alt screen, move to 
			 * lower left if we are using an alt screen.
			 */
			if (*sc_init != '\0' && *sc_deinit != '\0' && !no_alt_screen)
				lower_left();
			term_addrs = TRUE;
		}
		if (!no_keypad)
			ltputs(sc_s_keypad, sc_height, putchr);
		if (emouse != 0)
			init_mouse();
		if (no_paste)
			init_bracketed_paste();
	}
	if (top_scroll) 
	{
		int i;

		/*
		 * This is nice to terminals with no alternate screen,
		 * but with saved scrolled-off-the-top lines.  This way,
		 * no previous line is lost, but we start with a whole
		 * screen to ourself.
		 */
		for (i = 1; i < sc_height; i++)
			putchr('\n');
	} else
		line_left();
#else
#if MSDOS_COMPILER==WIN32C
	if (!(quit_if_one_screen && one_screen))
	{
		if (!no_init)
		{
			win32_init_term();
			term_addrs = TRUE;
		}
		if (emouse != 0)
			init_mouse();

	}
	win32_init_vt_term();
#endif
	initcolor();
	flush();
#endif
}

/*
 * Deinitialize terminal
 */
public void term_deinit(void)
{
	if (!term_init_done)
		return;
#if !MSDOS_COMPILER
	if (!(quit_if_one_screen && one_screen))
	{
		if (emouse != 0)
			deinit_mouse();
		if (no_paste)
			deinit_bracketed_paste();
		if (!no_keypad)
			ltputs(sc_e_keypad, sc_height, putchr);
		if (!no_init)
			ltputs(sc_deinit, sc_height, putchr);
	}
#else
	/* Restore system colors. */
	SETCOLORS(sy_fg_color, sy_bg_color);
#if MSDOS_COMPILER==WIN32C
	win32_deinit_vt_term();
	if (!(quit_if_one_screen && one_screen))
	{
		if (emouse != 0)
			deinit_mouse();
		if (!no_init)
			win32_deinit_term();
	}
#else
	/* Need clreol to make SETCOLORS take effect. */
	clreol();
#endif
#endif
	term_init_done = FALSE;
}

/*
 * Are we interactive (ie. writing to an initialized tty)?
 */
public lbool interactive(void)
{
	return (is_tty && term_init_done);
}

static void assert_interactive(void)
{
}

/*
 * Home cursor (move to upper left corner of screen).
 */
public void home(void)
{
	assert_interactive();
#if !MSDOS_COMPILER
	ltputs(sc_home, 1, putchr);
#else
	flush();
	_settextposition(1,1);
#endif
}

#if LESSTEST
public void dump_screen(void)
{
	char dump_cmd[32];
	SNPRINTF1(dump_cmd, sizeof(dump_cmd), ESCS"0;0;%dR", sc_width * sc_height);
	ltputs(dump_cmd, sc_height, putchr);
	flush();
}
#endif /*LESSTEST*/

/*
 * Add a blank line (called with cursor at home).
 * Should scroll the display down.
 */
public void add_line(void)
{
	assert_interactive();
#if !MSDOS_COMPILER
	ltputs(sc_addline, sc_height, putchr);
#else
	flush();
#if MSDOS_COMPILER==MSOFTC
	_scrolltextwindow(_GSCROLLDOWN);
	_settextposition(1,1);
#else
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
	movetext(1,1, sc_width,sc_height-1, 1,2);
	gotoxy(1,1);
	clreol();
#else
#if MSDOS_COMPILER==WIN32C
    {
	CHAR_INFO fillchar;
	SMALL_RECT rcSrc, rcClip;
	COORD new_org;
	CONSOLE_SCREEN_BUFFER_INFO csbi;

	GetConsoleScreenBufferInfo(con_out,&csbi);

	/* The clip rectangle is the entire visible screen. */
	rcClip.Left = csbi.srWindow.Left;
	rcClip.Top = csbi.srWindow.Top;
	rcClip.Right = csbi.srWindow.Right;
	rcClip.Bottom = csbi.srWindow.Bottom;

	/* The source rectangle is the visible screen minus the last line. */
	rcSrc = rcClip;
	rcSrc.Bottom--;

	/* Move the top left corner of the source window down one row. */
	new_org.X = rcSrc.Left;
	new_org.Y = rcSrc.Top + 1;

	/* Fill the right character and attributes. */
	fillchar.Char.AsciiChar = ' ';
	curr_attr = MAKEATTR(nm_fg_color, nm_bg_color);
	fillchar.Attributes = curr_attr;
	ScrollConsoleScreenBuffer(con_out, &rcSrc, &rcClip, new_org, &fillchar);
	_settextposition(1,1);
    }
#endif
#endif
#endif
#endif
}

#if 0
/*
 * Remove the n topmost lines and scroll everything below it in the 
 * window upward.  This is needed to stop leaking the topmost line 
 * into the scrollback buffer when we go down-one-line (in WIN32).
 */
public void remove_top(int n)
{
#if MSDOS_COMPILER==WIN32C
	SMALL_RECT rcSrc, rcClip;
	CHAR_INFO fillchar;
	COORD new_org;
	CONSOLE_SCREEN_BUFFER_INFO csbi; /* to get buffer info */

	if (n >= sc_height - 1)
	{
		lclear();
		home();
		return;
	}

	flush();

	GetConsoleScreenBufferInfo(con_out, &csbi);

	/* Get the extent of all-visible-rows-but-the-last. */
	rcSrc.Left    = csbi.srWindow.Left;
	rcSrc.Top     = csbi.srWindow.Top + n;
	rcSrc.Right   = csbi.srWindow.Right;
	rcSrc.Bottom  = csbi.srWindow.Bottom;

	/* Get the clip rectangle. */
	rcClip.Left   = rcSrc.Left;
	rcClip.Top    = csbi.srWindow.Top;
	rcClip.Right  = rcSrc.Right;
	rcClip.Bottom = rcSrc.Bottom ;

	/* Move the source window up n rows. */
	new_org.X = rcSrc.Left;
	new_org.Y = rcSrc.Top - n;

	/* Fill the right character and attributes. */
	fillchar.Char.AsciiChar = ' ';
	curr_attr = MAKEATTR(nm_fg_color, nm_bg_color);
	fillchar.Attributes = curr_attr;

	ScrollConsoleScreenBuffer(con_out, &rcSrc, &rcClip, new_org, &fillchar);

	/* Position cursor on first blank line. */
	goto_line(sc_height - n - 1);
#endif
}
#endif

#if MSDOS_COMPILER==WIN32C
/*
 * Clear the screen.
 */
static void win32_clear(void)
{
	/*
	 * This will clear only the currently visible rows of the NT
	 * console buffer, which means none of the precious scrollback
	 * rows are touched making for faster scrolling.  Note that, if
	 * the window has fewer columns than the console buffer (i.e.
	 * there is a horizontal scrollbar as well), the entire width
	 * of the visible rows will be cleared.
	 */
	COORD topleft;
	DWORD nchars;
	DWORD winsz;
	CONSOLE_SCREEN_BUFFER_INFO csbi;

	/* get the number of cells in the current buffer */
	GetConsoleScreenBufferInfo(con_out, &csbi);
	winsz = csbi.dwSize.X * (csbi.srWindow.Bottom - csbi.srWindow.Top + 1);
	topleft.X = 0;
	topleft.Y = csbi.srWindow.Top;

	curr_attr = MAKEATTR(nm_fg_color, nm_bg_color);
	FillConsoleOutputCharacter(con_out, ' ', winsz, topleft, &nchars);
	FillConsoleOutputAttribute(con_out, curr_attr, winsz, topleft, &nchars);
}

/*
 * Remove the n topmost lines and scroll everything below it in the 
 * window upward.
 */
public void win32_scroll_up(int n)
{
	SMALL_RECT rcSrc, rcClip;
	CHAR_INFO fillchar;
	COORD topleft;
	COORD new_org;
	DWORD nchars;
	DWORD size;
	CONSOLE_SCREEN_BUFFER_INFO csbi;

	if (n <= 0)
		return;

	if (n >= sc_height - 1)
	{
		win32_clear();
		_settextposition(1,1);
		return;
	}

	/* Get the extent of what will remain visible after scrolling. */
	GetConsoleScreenBufferInfo(con_out, &csbi);
	rcSrc.Left    = csbi.srWindow.Left;
	rcSrc.Top     = csbi.srWindow.Top + n;
	rcSrc.Right   = csbi.srWindow.Right;
	rcSrc.Bottom  = csbi.srWindow.Bottom;

	/* Get the clip rectangle. */
	rcClip.Left   = rcSrc.Left;
	rcClip.Top    = csbi.srWindow.Top;
	rcClip.Right  = rcSrc.Right;
	rcClip.Bottom = rcSrc.Bottom ;

	/* Move the source text to the top of the screen. */
	new_org.X = rcSrc.Left;
	new_org.Y = rcClip.Top;

	/* Fill the right character and attributes. */
	fillchar.Char.AsciiChar = ' ';
	fillchar.Attributes = MAKEATTR(nm_fg_color, nm_bg_color);

	/* Scroll the window. */
	SetConsoleTextAttribute(con_out, fillchar.Attributes);
	ScrollConsoleScreenBuffer(con_out, &rcSrc, &rcClip, new_org, &fillchar);

	/* Clear remaining lines at bottom. */
	topleft.X = csbi.dwCursorPosition.X;
	topleft.Y = rcSrc.Bottom - n;
	size = (n * csbi.dwSize.X) + (rcSrc.Right - topleft.X);
	FillConsoleOutputCharacter(con_out, ' ', size, topleft,
		&nchars);
	FillConsoleOutputAttribute(con_out, fillchar.Attributes, size, topleft,
		&nchars);
	SetConsoleTextAttribute(con_out, curr_attr);

	/* Move cursor n lines up from where it was. */
	csbi.dwCursorPosition.Y -= n;
	SetConsoleCursorPosition(con_out, csbi.dwCursorPosition);
}
#endif

/*
 * Move cursor to lower left corner of screen.
 */
public void lower_left(void)
{
	assert_interactive();
#if !MSDOS_COMPILER
	ltputs(sc_lower_left, 1, putchr);
#else
	flush();
	_settextposition(sc_height, 1);
#endif
}

/*
 * Move cursor to left position of current line.
 */
public void line_left(void)
{
	assert_interactive();
#if !MSDOS_COMPILER
	ltputs(sc_return, 1, putchr);
#else
	{
		int row;
		flush();
#if MSDOS_COMPILER==WIN32C
		{
			CONSOLE_SCREEN_BUFFER_INFO scr;
			GetConsoleScreenBufferInfo(con_out, &scr);
			row = scr.dwCursorPosition.Y - scr.srWindow.Top + 1;
		}
#else
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
			row = wherey();
#else
		{
			struct rccoord tpos = _gettextposition();
			row = tpos.row;
		}
#endif
#endif
		_settextposition(row, 1);
	}
#endif
}

/*
 * Check if the console size has changed and reset internals 
 * (in lieu of SIGWINCH for WIN32).
 */
public void check_winch(void)
{
#if MSDOS_COMPILER==WIN32C
	CONSOLE_SCREEN_BUFFER_INFO scr;
	COORD size;

	if (con_out == INVALID_HANDLE_VALUE)
		return;
 
	flush();
	GetConsoleScreenBufferInfo(con_out, &scr);
	size.Y = scr.srWindow.Bottom - scr.srWindow.Top + 1;
	size.X = scr.srWindow.Right - scr.srWindow.Left + 1;
	if (size.Y != sc_height || size.X != sc_width)
	{
		sc_height = size.Y;
		sc_width = size.X;
		if (!no_init && con_out_ours == con_out)
			SetConsoleScreenBufferSize(con_out, size);
		pos_init();
		screen_size_changed();
		screen_trashed();
	}
#endif
}

/*
 * Goto a specific line on the screen.
 */
public void goto_line(int sindex)
{
	assert_interactive();
#if !MSDOS_COMPILER
	ltputs(ltgoto(sc_move, 0, sindex), 1, putchr);
#else
	flush();
	_settextposition(sindex+1, 1);
#endif
}

#if MSDOS_COMPILER==MSOFTC || MSDOS_COMPILER==BORLANDC
/*
 * Create an alternate screen which is all white.
 * This screen is used to create a "flash" effect, by displaying it
 * briefly and then switching back to the normal screen.
 * {{ Yuck!  There must be a better way to get a visual bell. }}
 */
static void create_flash(void)
{
#if MSDOS_COMPILER==MSOFTC
	struct videoconfig w;
	char *blanks;
	int row, col;
	
	_getvideoconfig(&w);
	videopages = w.numvideopages;
	if (videopages < 2)
	{
		at_enter(AT_STANDOUT);
		at_exit();
	} else
	{
		_setactivepage(1);
		at_enter(AT_STANDOUT);
		blanks = (char *) ecalloc(w.numtextcols, sizeof(char));
		for (col = 0;  col < w.numtextcols;  col++)
			blanks[col] = ' ';
		for (row = w.numtextrows;  row > 0;  row--)
			_outmem(blanks, w.numtextcols);
		_setactivepage(0);
		_setvisualpage(0);
		free(blanks);
		at_exit();
	}
#else
#if MSDOS_COMPILER==BORLANDC
	int n;

	whitescreen = (unsigned short *) 
		malloc(sc_width * sc_height * sizeof(short));
	if (whitescreen == NULL)
		return;
	for (n = 0;  n < sc_width * sc_height;  n++)
		whitescreen[n] = 0x7020;
#endif
#endif
	flash_created = 1;
}
#endif /* MSDOS_COMPILER */

/*
 * Output the "visual bell", if there is one.
 */
public void vbell(void)
{
	if (no_vbell)
		return;
#if !MSDOS_COMPILER
	if (*sc_visual_bell == '\0')
		return;
	ltputs(sc_visual_bell, sc_height, putchr);
#else
#if MSDOS_COMPILER==DJGPPC
	ScreenVisualBell();
#else
#if MSDOS_COMPILER==MSOFTC
	/*
	 * Create a flash screen on the second video page.
	 * Switch to that page, then switch back.
	 */
	if (!flash_created)
		create_flash();
	if (videopages < 2)
		return;
	_setvisualpage(1);
	delay(100);
	_setvisualpage(0);
#else
#if MSDOS_COMPILER==BORLANDC
	unsigned short *currscreen;

	/*
	 * Get a copy of the current screen.
	 * Display the flash screen.
	 * Then restore the old screen.
	 */
	if (!flash_created)
		create_flash();
	if (whitescreen == NULL)
		return;
	currscreen = (unsigned short *) 
		malloc(sc_width * sc_height * sizeof(short));
	if (currscreen == NULL) return;
	gettext(1, 1, sc_width, sc_height, currscreen);
	puttext(1, 1, sc_width, sc_height, whitescreen);
	delay(100);
	puttext(1, 1, sc_width, sc_height, currscreen);
	free(currscreen);
#else
#if MSDOS_COMPILER==WIN32C
	/* paint screen with an inverse color */
	lclear();

	/* leave it displayed for 100 msec. */
	Sleep(100);

	/* restore with a redraw */
	repaint();
#endif
#endif
#endif
#endif
#endif
}

/*
 * Make a noise.
 */
static void lbeep(void)
{
#if !MSDOS_COMPILER
	putchr(CONTROL('G'));
#else
#if MSDOS_COMPILER==WIN32C
	MessageBeep(0);
#else
	write(1, "\7", 1);
#endif
#endif
}

/*
 * Ring the terminal bell.
 */
public void lbell(void)
{
	if (quiet == VERY_QUIET)
		vbell();
	else
		lbeep();
}

/*
 * Clear the screen.
 */
public void lclear(void)
{
	assert_interactive();
	suspend_screen();
#if !MSDOS_COMPILER
	ltputs(sc_clear, sc_height, putchr);
#else
	flush();
#if MSDOS_COMPILER==WIN32C
	win32_clear();
#else
	_clearscreen(_GCLEARSCREEN);
#endif
#endif
}

/*
 * Clear from the cursor to the end of the cursor's line.
 * {{ This must not move the cursor. }}
 */
public void clear_eol(void)
{
	/* assert_interactive();*/
#if !MSDOS_COMPILER
	ltputs(sc_eol_clear, 1, putchr);
#else
#if MSDOS_COMPILER==MSOFTC
	short top, left;
	short bot, right;
	struct rccoord tpos;
	
	flush();
	/*
	 * Save current state.
	 */
	tpos = _gettextposition();
	_gettextwindow(&top, &left, &bot, &right);
	/*
	 * Set a temporary window to the current line,
	 * from the cursor's position to the right edge of the screen.
	 * Then clear that window.
	 */
	_settextwindow(tpos.row, tpos.col, tpos.row, sc_width);
	_clearscreen(_GWINDOW);
	/*
	 * Restore state.
	 */
	_settextwindow(top, left, bot, right);
	_settextposition(tpos.row, tpos.col);
#else
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
	flush();
	clreol();
#else
#if MSDOS_COMPILER==WIN32C
	DWORD           nchars;
	COORD           cpos;
	CONSOLE_SCREEN_BUFFER_INFO scr;

	flush();
	memset(&scr, 0, sizeof(scr));
	GetConsoleScreenBufferInfo(con_out, &scr);
	cpos.X = scr.dwCursorPosition.X;
	cpos.Y = scr.dwCursorPosition.Y;
	curr_attr = MAKEATTR(nm_fg_color, nm_bg_color);
	FillConsoleOutputAttribute(con_out, curr_attr,
		scr.dwSize.X - cpos.X, cpos, &nchars);
	FillConsoleOutputCharacter(con_out, ' ',
		scr.dwSize.X - cpos.X, cpos, &nchars);
#endif
#endif
#endif
#endif
}

/*
 * Clear the current line.
 * Clear the screen if there's off-screen memory below the display.
 */
static void clear_eol_bot(void)
{
	assert_interactive();
#if MSDOS_COMPILER
	clear_eol();
#else
	if (below_mem)
		ltputs(sc_eos_clear, 1, putchr);
	else
		ltputs(sc_eol_clear, 1, putchr);
#endif
}

/*
 * Clear the bottom line of the display.
 * Leave the cursor at the beginning of the bottom line.
 */
public void clear_bot(void)
{
	/*
	 * If we're in a non-normal attribute mode, temporarily exit
	 * the mode while we do the clear.  Some terminals fill the
	 * cleared area with the current attribute.
	 */
	if (oldbot)
		lower_left();
	else
		line_left();

	if (attrmode == AT_NORMAL)
		clear_eol_bot();
	else
	{
		int saved_attrmode = attrmode;

		at_exit();
		clear_eol_bot();
		at_enter(saved_attrmode);
	}
}

/*
 * Enable or disable bracketed paste mode.
 * When enabled, the terminal sends an "open bracket" sequence 
 * before pasted content and "close bracket" after it.
 */
public void init_bracketed_paste(void)
{
#if !MSDOS_COMPILER
	ltputs(sc_s_bracketed_paste, 1, putchr);
#endif
}

public void deinit_bracketed_paste(void)
{
#if !MSDOS_COMPILER
	ltputs(sc_e_bracketed_paste, 1, putchr);
#endif
}

/*
 * Color string may be "x[y]" where x and y are 4-bit color chars,
 * or "N[.M]" where N and M are decimal integers>
 * Any of x,y,N,M may also be "-" to mean "unchanged".
 */

/*
 * Parse a 4-bit color char.
 */
static int parse_color4(char ch)
{
	switch (ch)
	{
	case 'k': return 0;
	case 'r': return CV_RED;
	case 'g': return CV_GREEN;
	case 'y': return CV_RED|CV_GREEN;
	case 'b': return CV_BLUE;
	case 'm': return CV_RED|CV_BLUE;
	case 'c': return CV_GREEN|CV_BLUE;
	case 'w': return CV_RED|CV_GREEN|CV_BLUE;
	case 'K': return 0|CV_BRIGHT;
	case 'R': return CV_RED|CV_BRIGHT;
	case 'G': return CV_GREEN|CV_BRIGHT;
	case 'Y': return CV_RED|CV_GREEN|CV_BRIGHT;
	case 'B': return CV_BLUE|CV_BRIGHT;
	case 'M': return CV_RED|CV_BLUE|CV_BRIGHT;
	case 'C': return CV_GREEN|CV_BLUE|CV_BRIGHT;
	case 'W': return CV_RED|CV_GREEN|CV_BLUE|CV_BRIGHT;
	case '-': return CV_NOCHANGE;
	default:  return CV_ERROR;
	}
}

/*
 * Parse a color as a decimal integer.
 */
static int parse_color6(constant char **ps)
{
	if (**ps == '-')
	{
		(*ps)++;
		return CV_NOCHANGE;
	} else
	{
		constant char *os = *ps;
		int color = lstrtoic(os, ps, 10);
		if (color < 0 || *ps == os)
			return CV_ERROR;
		return color;
	}
}

/*
 * Parse a color pair and return the foreground/background/attribute values.
 * Return type of color specifier:
 *  CV_4BIT: fg/bg values are OR of CV_{RGB} bits.
 *  CV_6BIT: fg/bg values are integers entered by user.
 */
public COLOR_TYPE parse_color(constant char *str, mutable int *p_fg, mutable int *p_bg, mutable CHAR_ATTR *p_cattr)
{
	int fg;
	int bg = CV_ERROR;
	CHAR_ATTR cattr = CATTR_NULL;
	COLOR_TYPE type = CT_NULL;

	if (str == NULL || *str == '\0')
		return CT_NULL;
	if (*str == '+')
		str++; /* ignore leading + */

	fg = parse_color4(*str);
	if (fg != CV_ERROR)
	{
		if (str[1] == '\0' || strchr("*~_&dsul", str[1]) != NULL)
		{
			bg = CV_NOCHANGE;
			str++; /* skip the fg char */
		} else
		{
			bg = parse_color4(str[1]);
			if (bg != CV_ERROR)
				str += 2; /* skip both fg and bg chars */
		}
	}
	if (fg != CV_ERROR && bg != CV_ERROR)
		type = CT_4BIT;
	else
	{
		fg = (*str == '.') ? CV_NOCHANGE : parse_color6(&str);
		if (fg != CV_ERROR)
		{
			if (*str != '.')
				bg = CV_NOCHANGE;
			else
			{
				str++; /* skip the dot */
				bg = parse_color6(&str);
			}
		}
		if (fg != CV_ERROR && bg != CV_ERROR)
			type = CT_6BIT;
	}
	if (type != CT_NULL)
	{
		for (;; str++)
		{
			if (*str == '*' || *str == 'd')
				cattr |= CATTR_BOLD;
			else if (*str == '~' || *str == 's')
				cattr |= CATTR_STANDOUT;
			else if (*str == '_' || *str == 'u')
				cattr |= CATTR_UNDERLINE;
			else if (*str == '&' || *str == 'l') /* can't use 'k' because of conflict with "black" */
				cattr |= CATTR_BLINK;
			else
				break;
		}
		if (p_fg != NULL) *p_fg = fg;
		if (p_bg != NULL) *p_bg = bg;
		if (p_cattr != NULL) *p_cattr = cattr;
	}
	return type;
}

#if !MSDOS_COMPILER

static int sgr_color(int color)
{
	switch (color)
	{
	case 0:                                    return 30;
	case CV_RED:                               return 31;
	case CV_GREEN:                             return 32;
	case CV_RED|CV_GREEN:                      return 33;
	case CV_BLUE:                              return 34;
	case CV_RED|CV_BLUE:                       return 35;
	case CV_GREEN|CV_BLUE:                     return 36;
	case CV_RED|CV_GREEN|CV_BLUE:              return 37;

	case CV_BRIGHT:                            return 90;
	case CV_RED|CV_BRIGHT:                     return 91;
	case CV_GREEN|CV_BRIGHT:                   return 92;
	case CV_RED|CV_GREEN|CV_BRIGHT:            return 93;
	case CV_BLUE|CV_BRIGHT:                    return 94;
	case CV_RED|CV_BLUE|CV_BRIGHT:             return 95;
	case CV_GREEN|CV_BLUE|CV_BRIGHT:           return 96;
	case CV_RED|CV_GREEN|CV_BLUE|CV_BRIGHT:    return 97;

	default: return color;
	}
}

static void tput_fmt(constant char *fmt, int color, int (*f_putc)(int))
{
	char buf[INT_STRLEN_BOUND(int)+16];
	if (color == attrcolor)
		return;
	SNPRINTF1(buf, sizeof(buf), fmt, color);
	ltputs(buf, 1, f_putc);
	attrcolor = color;
}

static void tput_char_cattr(CHAR_ATTR cattr, int (*f_putc)(int))
{
	if (cattr & CATTR_UNDERLINE)
	{
		ltputs(sc_u_in, 1, f_putc);
		attrbits |= AT_UNDERLINE;
	}
	if (cattr & CATTR_BOLD)
	{
		ltputs(sc_b_in, 1, f_putc);
		attrbits |= AT_BOLD;
	}
	if (cattr & CATTR_BLINK)
	{
		ltputs(sc_bl_in, 1, f_putc);
		attrbits |= AT_BLINK;
	}
	if (cattr & CATTR_STANDOUT)
	{
		ltputs(sc_s_in, 1, f_putc);
		attrbits |= AT_STANDOUT;
	}
}

static void tput_color(constant char *str, int (*f_putc)(int))
{
	int fg;
	int bg;
	CHAR_ATTR cattr;

	if (str != NULL && strcmp(str, "*") == 0)
	{
		/* Special case: reset to normal */
		tput_fmt(ESCS"[m", -1, f_putc);
		return;
	}
	switch (parse_color(str, &fg, &bg, &cattr))
	{
	case CT_4BIT:
		if (fg >= 0)
			tput_fmt(ESCS"[%dm", sgr_color(fg), f_putc);
		if (bg >= 0)
			tput_fmt(ESCS"[%dm", sgr_color(bg)+10, f_putc);
		tput_char_cattr(cattr, f_putc);
		break;
	case CT_6BIT:
		if (fg >= 0)
			tput_fmt(ESCS"[38;5;%dm", fg, f_putc);
		if (bg >= 0)
			tput_fmt(ESCS"[48;5;%dm", bg, f_putc);
		tput_char_cattr(cattr, f_putc);
		break;
	default:
		break;
	}
}

static void tput_inmode(constant char *mode_str, int attr, int attr_bit, int (*f_putc)(int))
{
	constant char *color_str;
	if ((attr & attr_bit) == 0)
		return;
	color_str = get_color_map(attr_bit);
	if (color_str == NULL || *color_str == '\0' || *color_str == '+')
	{
		ltputs(mode_str, 1, f_putc);
		attrbits |= attr_bit;
		if (color_str == NULL || *color_str++ != '+')
			return;
	}
	/* Color overrides mode string */
	tput_color(color_str, f_putc);
}

static void tput_outmode(constant char *mode_str, int attr_bit, int (*f_putc)(int))
{
	if ((attrbits & attr_bit) == 0)
		return;
	ltputs(mode_str, 1, f_putc);
	attrbits &= ~attr_bit;
}

#else /* MSDOS_COMPILER */

#if MSDOS_COMPILER==WIN32C
static lbool WIN32put_fmt(constant char *fmt, int color)
{
	char buf[INT_STRLEN_BOUND(int)+16];
	int len = (size_t) SNPRINTF1(buf, sizeof(buf), fmt, color);
	if (len > 0)
		WIN32textout(buf, (size_t) len);
	return TRUE;
}

static void win_set_cattr(CHAR_ATTR cattr)
{
	if (cattr & CATTR_UNDERLINE)
		WIN32textout(ESCS"[4m", 4);
	if (cattr & CATTR_BOLD)
		WIN32textout(ESCS"[1m", 4);
	if (cattr & CATTR_BLINK)
		WIN32textout(ESCS"[5m", 4);
	if (cattr & CATTR_STANDOUT)
		WIN32textout(ESCS"[7m", 4);
}
#endif

static lbool win_set_color(int attr)
{
	int fg;
	int bg;
	CHAR_ATTR cattr;
	lbool out = FALSE;
	constant char *str = get_color_map(attr);
	if (str == NULL || str[0] == '\0')
		return FALSE;
	switch (parse_color(str, &fg, &bg, &cattr))
	{
	case CT_4BIT:
		if (fg >= 0 && bg >= 0)
		{
			SETCOLORS(fg, bg);
			out = TRUE;
		} else if (fg >= 0)
		{
			SET_FG_COLOR(fg);
			out = TRUE;
		} else if (bg >= 0)
		{
			SET_BG_COLOR(bg);
			out = TRUE;
		}
#if MSDOS_COMPILER==WIN32C
		if (vt_enabled)
			win_set_cattr(cattr);
#endif
		break;
#if MSDOS_COMPILER==WIN32C
	case CT_6BIT:
		if (vt_enabled)
		{
			if (fg > 0)
				out = WIN32put_fmt(ESCS"[38;5;%dm", fg);
			if (bg > 0)
				out = WIN32put_fmt(ESCS"[48;5;%dm", bg);
			win_set_cattr(cattr);
		}
		break;
#endif
	default:
		break;
	}
	return out;
}

#endif /* MSDOS_COMPILER */

public void at_enter(int attr)
{
	attr = apply_at_specials(attr);
#if !MSDOS_COMPILER
	/* The one with the most priority is last.  */
	tput_inmode(sc_u_in, attr, AT_UNDERLINE, putchr);
	tput_inmode(sc_b_in, attr, AT_BOLD, putchr);
	tput_inmode(sc_bl_in, attr, AT_BLINK, putchr);
	/* Don't use standout and color at the same time. */
	if (use_color && (attr & AT_COLOR))
		tput_color(get_color_map(attr), putchr);
	else
		tput_inmode(sc_s_in, attr, AT_STANDOUT, putchr);
#else
	flush();
	/* The one with the most priority is first.  */
	if ((attr & AT_COLOR) && use_color)
	{
		win_set_color(attr);
	} else if (attr & AT_STANDOUT)
	{
		SETCOLORS(so_fg_color, so_bg_color);
	} else if (attr & AT_BLINK)
	{
		SETCOLORS(bl_fg_color, bl_bg_color);
	} else if (attr & AT_BOLD)
	{
		SETCOLORS(bo_fg_color, bo_bg_color);
	} else if (attr & AT_UNDERLINE)
	{
		SETCOLORS(ul_fg_color, ul_bg_color);
	}
#endif
	attrmode = attr;
}

public void at_exit(void)
{
#if !MSDOS_COMPILER
	/* Undo things in the reverse order we did them.  */
	tput_color("*", putchr);
	tput_outmode(sc_s_out, AT_STANDOUT, putchr);
	tput_outmode(sc_bl_out, AT_BLINK, putchr);
	tput_outmode(sc_b_out, AT_BOLD, putchr);
	tput_outmode(sc_u_out, AT_UNDERLINE, putchr);
#else
	flush();
	SETCOLORS(nm_fg_color, nm_bg_color);
#endif
	attrmode = AT_NORMAL;
}

public void at_switch(int attr)
{
	int new_attrmode = apply_at_specials(attr);
	int ignore_modes = AT_ANSI;

	if ((new_attrmode & ~ignore_modes) != (attrmode & ~ignore_modes))
	{
		at_exit();
		at_enter(attr);
	}
}

public lbool is_at_equiv(int attr1, int attr2)
{
	attr1 = apply_at_specials(attr1);
	attr2 = apply_at_specials(attr2);

	return (attr1 == attr2);
}

public int apply_at_specials(int attr)
{
	if (attr & AT_BINARY)
		attr |= binattr;
	if (attr & AT_HILITE)
		attr |= AT_STANDOUT;
	attr &= ~(AT_BINARY|AT_HILITE);

	return attr;
}

/*
 * Output a plain backspace, without erasing the previous char.
 */
public void putbs(void)
{
	if (termcap_debug)
		putstr("<bs>");
	else
	{
#if !MSDOS_COMPILER
	ltputs(sc_backspace, 1, putchr);
#else
	int row, col;

	flush();
	{
#if MSDOS_COMPILER==MSOFTC
		struct rccoord tpos;
		tpos = _gettextposition();
		row = tpos.row;
		col = tpos.col;
#else
#if MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
		row = wherey();
		col = wherex();
#else
#if MSDOS_COMPILER==WIN32C
		CONSOLE_SCREEN_BUFFER_INFO scr;
		GetConsoleScreenBufferInfo(con_out, &scr);
		row = scr.dwCursorPosition.Y - scr.srWindow.Top + 1;
		col = scr.dwCursorPosition.X - scr.srWindow.Left + 1;
#endif
#endif
#endif
	}
	if (col <= 1)
		return;
	_settextposition(row, col-1);
#endif /* MSDOS_COMPILER */
	}
}

#if MSDOS_COMPILER==WIN32C

#define WIN32_MAX_REPEAT 3
#define LAST_DOWN_COUNT 8
static LWCHAR last_downs[LAST_DOWN_COUNT] = { 0 };
static int last_down_index = 0;
static LWCHAR hi_surr = 0;

typedef struct XINPUT_RECORD {
	INPUT_RECORD ir;
	LWCHAR ichar; /* because ir...UnicodeChar is only 16 bits */
} XINPUT_RECORD;

typedef struct WIN32_CHAR {
	struct WIN32_CHAR *wc_next;
	int wc_ch;
} WIN32_CHAR;

static WIN32_CHAR *win32_queue = NULL;

/*
 * Is the win32_queue nonempty?
 */
static lbool win32_queued_char(void)
{
	return (win32_queue != NULL);
}

/*
 * Push a char onto the back of the win32_queue.
 */
static void win32_enqueue(int ch)
{
	WIN32_CHAR *wch = (WIN32_CHAR *) ecalloc(1, sizeof(WIN32_CHAR));
	wch->wc_ch = ch;
	wch->wc_next = NULL;
	if (win32_queue == NULL)
		win32_queue = wch;
	else
	{
		WIN32_CHAR *pch;
		for (pch = win32_queue; pch->wc_next != NULL; pch = pch->wc_next)
			continue;
		pch->wc_next = wch;
	}
}

/*
 * Push a char onto the front of the win32_queue.
 * Makes the next call to WIN32getch return ch.
 */
public void WIN32ungetch(int ch)
{
	WIN32_CHAR *wch = (WIN32_CHAR *) ecalloc(1, sizeof(WIN32_CHAR));
	wch->wc_ch = ch;
	wch->wc_next = win32_queue;
	win32_queue = wch;
}

/*
 * Get a char from the front of the win32_queue.
 */
static int win32_get_queue(void)
{
	WIN32_CHAR *wch = win32_queue;
	int ch = wch->wc_ch;
	win32_queue = wch->wc_next;
	free(wch);
	return ch;
}

/*
 * Handle a mouse input event.
 */
static lbool win32_mouse_event(XINPUT_RECORD *xip)
{
	char b;

	if (emouse == 0 || xip->ir.EventType != MOUSE_EVENT)
		return (FALSE);

	/* Generate an X11 mouse sequence from the mouse event. */
	/* TODO: switch to the 1006 protocol to allow specific-button-up reports */
	switch (xip->ir.Event.MouseEvent.dwEventFlags)
	{
	case 0: /* press or release */
		if (xip->ir.Event.MouseEvent.dwButtonState == 0)
			b = X11MOUSE_OFFSET + X11MOUSE_BUTTON_REL;
		else if (xip->ir.Event.MouseEvent.dwButtonState == 1)  /* leftmost */
			b = X11MOUSE_OFFSET + X11MOUSE_BUTTON1;
		else if (xip->ir.Event.MouseEvent.dwButtonState == 2)  /* rightmost */
			b = X11MOUSE_OFFSET + X11MOUSE_BUTTON3;
		else if (xip->ir.Event.MouseEvent.dwButtonState == 4)  /* middle ("next-to-leftmost") */
			b = X11MOUSE_OFFSET + X11MOUSE_BUTTON2;
		else  /* don't bother to figure out what changed */
			return (FALSE);
		break;
	case MOUSE_WHEELED:
		b = X11MOUSE_OFFSET + (((int)xip->ir.Event.MouseEvent.dwButtonState < 0) ? X11MOUSE_WHEEL_DOWN : X11MOUSE_WHEEL_UP);
		break;
	case MOUSE_MOVED:
		if (xip->ir.Event.MouseEvent.dwButtonState != 1)
			return (FALSE);
		/* Drag with left button down. */
		b = X11MOUSE_OFFSET + X11MOUSE_DRAG;
		break;
	default:
		return (FALSE);
	}
	/* {{ TODO: change to X11 1006 format. }} */
	win32_enqueue(ESC);
	win32_enqueue('[');
	win32_enqueue('M');
	win32_enqueue(b);
	win32_enqueue(X11MOUSE_OFFSET + xip->ir.Event.MouseEvent.dwMousePosition.X + 1);
	win32_enqueue(X11MOUSE_OFFSET + xip->ir.Event.MouseEvent.dwMousePosition.Y + 1);
	return (TRUE);
}

static void set_last_down(LWCHAR ch)
{
	if (ch == 0) return;
	last_downs[last_down_index] = ch;
	if (++last_down_index >= LAST_DOWN_COUNT)
		last_down_index = 0;
}

static LWCHAR *find_last_down(LWCHAR ch)
{
	int i;
	for (i = 0; i < LAST_DOWN_COUNT; ++i)
		if (last_downs[i] == ch)
			return &last_downs[i];
	return NULL;
}

/*
 * Get an input char from an INPUT_RECORD and store in xip->ichar.
 * Handles surrogate chars, and KeyUp without previous corresponding KeyDown.
 */
static lbool win32_get_ichar(XINPUT_RECORD *xip)
{
	LWCHAR ch = xip->ir.Event.KeyEvent.uChar.UnicodeChar;
	xip->ichar = ch;
	if (!is_ascii_char(ch))
	{
		int is_down = xip->ir.Event.KeyEvent.bKeyDown;
		LWCHAR *last_down = find_last_down(ch);
		if (last_down == NULL) { /* key was up */
			if (is_down) { /* key was up, now is down */
				set_last_down(ch);
			} else { /* key up without previous down: pretend this is a down. */
				xip->ir.Event.KeyEvent.bKeyDown = 1;
			}
		} else if (!is_down) { /* key was down, now is up */
			*last_down = 0; /* use this last_down only once */
		}

		if (ch >= 0xD800 && ch < 0xDC00) { /* high surrogate */
			hi_surr = 0x10000 + ((ch - 0xD800) << 10);
			return (FALSE); /* get next input, which should be the low surrogate */
		}
		if (ch >= 0xDC00 && ch < 0xE000) { /* low surrogate */
			xip->ichar = hi_surr + (ch - 0xDC00);
			hi_surr = 0;
		}
	}
	return (TRUE);
}

/*
 * Handle a scan code (non-ASCII) key input.
 */
static lbool win32_scan_code(XINPUT_RECORD *xip)
{
	int scan = -1;
	if (xip->ir.Event.KeyEvent.dwControlKeyState & (LEFT_CTRL_PRESSED | RIGHT_CTRL_PRESSED))
	{
		switch (xip->ir.Event.KeyEvent.wVirtualScanCode)
		{
		case PCK_RIGHT: /* right arrow */
			scan = PCK_CTL_RIGHT;
			break;
		case PCK_LEFT: /* left arrow */
			scan = PCK_CTL_LEFT;
			break;
		case PCK_DELETE: /* delete */
			scan = PCK_CTL_DELETE;
			break;
		case PCK_HOME:
			scan = PCK_CTL_HOME;
			break;
		case PCK_END:
			scan = PCK_CTL_END;
			break;
		}
	} else if (xip->ir.Event.KeyEvent.dwControlKeyState & SHIFT_PRESSED)
	{
		if (xip->ichar == '\t')
			scan = PCK_SHIFT_TAB;
		else
		{
			switch (xip->ir.Event.KeyEvent.wVirtualScanCode)
			{
				case PCK_RIGHT:
					scan = PCK_SHIFT_RIGHT;
					break;
				case PCK_LEFT:
					scan = PCK_SHIFT_LEFT;
					break;
				case PCK_HOME:
					scan = PCK_SHIFT_HOME;
					break;
				case PCK_END:
					scan = PCK_SHIFT_END;
					break;
			}
		}
	}
	if (scan < 0 && xip->ichar == 0)
		scan = xip->ir.Event.KeyEvent.wVirtualScanCode;
	if (scan < 0)
		return (FALSE);
	/*
	 * An extended key returns a 2 byte sequence consisting of
	 * a zero byte followed by the scan code.
	 */
	win32_enqueue('\0');
	win32_enqueue(scan);
	return (TRUE);
}

/*
 * Handle a key input event.
 */
static lbool win32_key_event(XINPUT_RECORD *xip)
{
	int repeat;
	char utf8[UTF8_MAX_LENGTH];
	char *up;

	if (xip->ir.EventType != KEY_EVENT ||
	    ((xip->ir.Event.KeyEvent.dwControlKeyState & (RIGHT_ALT_PRESSED|LEFT_CTRL_PRESSED)) == (RIGHT_ALT_PRESSED|LEFT_CTRL_PRESSED) && xip->ir.Event.KeyEvent.uChar.UnicodeChar == 0) ||
	    (xip->ir.Event.KeyEvent.wVirtualScanCode == 0 && xip->ir.Event.KeyEvent.uChar.UnicodeChar == 0) ||
	    xip->ir.Event.KeyEvent.wVirtualScanCode == PCK_CAPS_LOCK ||
	    xip->ir.Event.KeyEvent.wVirtualScanCode == PCK_NUM_LOCK ||
	    (xip->ir.Event.KeyEvent.wVirtualKeyCode == VK_MENU && xip->ir.Event.KeyEvent.uChar.UnicodeChar == 0) ||
	    xip->ir.Event.KeyEvent.wVirtualKeyCode == VK_KANJI ||
	    xip->ir.Event.KeyEvent.wVirtualKeyCode == VK_SHIFT ||
	    xip->ir.Event.KeyEvent.wVirtualKeyCode == VK_CONTROL)
		return (FALSE);

	if (!win32_get_ichar(xip))
		return (FALSE);
	if (!xip->ir.Event.KeyEvent.bKeyDown)
		return (FALSE);
		
	if (win32_scan_code(xip))
		return (TRUE);

	repeat = xip->ir.Event.KeyEvent.wRepeatCount;
	if (repeat > WIN32_MAX_REPEAT)
		repeat = WIN32_MAX_REPEAT;
	up = utf8;
	put_wchar(&up, xip->ichar);
	for (; repeat > 0; --repeat)
	{
		constant char *p;
		for (p = utf8; p < up; ++p)
			 win32_enqueue((unsigned char) *p);
	}
	return (TRUE);
}

/*
 * Handle a window input event.
 */
static lbool win32_window_event(XINPUT_RECORD *xip)
{
	if (xip->ir.EventType != WINDOW_BUFFER_SIZE_EVENT)
		return (FALSE);
	win32_enqueue(READ_AGAIN);
	return (TRUE);
}

/*
 * Determine whether an input character is waiting to be read.
 */
public lbool win32_kbhit2(lbool no_queued)
{
	XINPUT_RECORD xip;

	if (!no_queued && win32_queued_char())
		return (TRUE);

	for (;;)
	{
		DWORD nread;
		DWORD console_input_mode;
		/*
		 * When an input pipe closes, cmd may reset the console mode,
		 * so set the mode every time we read input.
		 */
		if (GetConsoleMode(tty, &console_input_mode) && console_input_mode != curr_console_input_mode)
			SetConsoleMode(tty, curr_console_input_mode);
		PeekConsoleInputW(tty, &xip.ir, 1, &nread);
		if (nread == 0)
			return (FALSE);
		ReadConsoleInputW(tty, &xip.ir, 1, &nread);
		if (nread == 0)
			return (FALSE);
		if (win32_mouse_event(&xip) || win32_key_event(&xip) || win32_window_event(&xip))
			break;
	}
	return (TRUE);
}

public lbool win32_kbhit(void)
{
	return win32_kbhit2(FALSE);
}

/*
 * Read a character from the keyboard.
 */
public int WIN32getch(void)
{
	while (!win32_kbhit())
	{
		Sleep(20);
		if (ABORT_SIGS())
			return ('\003');
	}
	return (win32_get_queue());
}

public void win32_getch_clear(void)
{
	while (win32_kbhit())
		(void) WIN32getch();
}

#endif /* MSDOS_COMPILER==WIN32C */

#if MSDOS_COMPILER
/*
 */
public void WIN32setcolors(int fg, int bg)
{
	SETCOLORS(fg, bg);
}

/*
 */
public void WIN32textout(constant char *text, size_t len)
{
#if MSDOS_COMPILER==WIN32C
	DWORD written;
	if (utf_mode == 2)
	{
		/*
		 * We've got UTF-8 text in a non-UTF-8 console.  Convert it to
		 * wide and use WriteConsoleW.
		 * Biggest input len is OUTBUF_SIZE of obuf from win_flush,
		 * which is also the biggest output count if it's ASCII.
		 * "static" wtext is not a state - only avoid 16K on stack.
		 */
		static WCHAR wtext[OUTBUF_SIZE];
		len = MultiByteToWideChar(CP_UTF8, 0, text, len, wtext, countof(wtext));
		WriteConsoleW(con_out, wtext, len, &written, NULL);
	} else
		WriteConsole(con_out, text, (DWORD) len, &written, NULL);
#else
	char buf[2048];
	if (len >= sizeof(buf))
		len = sizeof(buf) - 1;
	memcpy(buf, text, len);
	buf[len] = 0;
	cputs(buf);
#endif
}
#endif