st/st.c

/* See LICENSE for license details. */
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <locale.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>
#include <libgen.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/cursorfont.h>
#include <X11/keysym.h>
#include <X11/Xft/Xft.h>
#include <X11/XKBlib.h>
#include <fontconfig/fontconfig.h>
#include <wchar.h>

#include "arg.h"

char *argv0;

#define Glyph Glyph_
#define Font Font_

#if   defined(__linux)
 #include <pty.h>
#elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__APPLE__)
 #include <util.h>
#elif defined(__FreeBSD__) || defined(__DragonFly__)
 #include <libutil.h>
#endif


/* XEMBED messages */
#define XEMBED_FOCUS_IN  4
#define XEMBED_FOCUS_OUT 5

/* Arbitrary sizes */
#define UTF_INVALID   0xFFFD
#define UTF_SIZ       4
#define ESC_BUF_SIZ   (128*UTF_SIZ)
#define ESC_ARG_SIZ   16
#define STR_BUF_SIZ   ESC_BUF_SIZ
#define STR_ARG_SIZ   ESC_ARG_SIZ
#define XK_ANY_MOD    UINT_MAX
#define XK_NO_MOD     0
#define XK_SWITCH_MOD (1<<13)
#define OPAQUE 0Xff

/* macros */
#define MIN(a, b)		((a) < (b) ? (a) : (b))
#define MAX(a, b)		((a) < (b) ? (b) : (a))
#define LEN(a)			(sizeof(a) / sizeof(a)[0])
#define NUMMAXLEN(x)		((int)(sizeof(x) * 2.56 + 0.5) + 1)
#define DEFAULT(a, b)		(a) = (a) ? (a) : (b)
#define BETWEEN(x, a, b)	((a) <= (x) && (x) <= (b))
#define DIVCEIL(n, d)		(((n) + ((d) - 1)) / (d))
#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == '\177')
#define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
#define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
#define ISDELIM(u)		(utf8strchr(worddelimiters, u) != NULL)
#define LIMIT(x, a, b)		(x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x)
#define ATTRCMP(a, b)		((a).mode != (b).mode || (a).fg != (b).fg || \
				(a).bg != (b).bg)
#define IS_SET(flag)		((term.mode & (flag)) != 0)
#define TIMEDIFF(t1, t2)	((t1.tv_sec-t2.tv_sec)*1000 + \
				(t1.tv_nsec-t2.tv_nsec)/1E6)
#define MODBIT(x, set, bit)	((set) ? ((x) |= (bit)) : ((x) &= ~(bit)))

#define USE_ARGB (alpha != OPAQUE && opt_embed == NULL)

#define TRUECOLOR(r,g,b)	(1 << 24 | (r) << 16 | (g) << 8 | (b))
#define IS_TRUECOL(x)		(1 << 24 & (x))
#define TRUERED(x)		(((x) & 0xff0000) >> 8)
#define TRUEGREEN(x)		(((x) & 0xff00))
#define TRUEBLUE(x)		(((x) & 0xff) << 8)
#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - term.scr \
				+ histsize + 1) % histsize] : term.line[(y) - term.scr])

/* constants */
#define ISO14755CMD		"dmenu -p codepoint: </dev/null"

enum glyph_attribute {
	ATTR_NULL       = 0,
	ATTR_BOLD       = 1 << 0,
	ATTR_FAINT      = 1 << 1,
	ATTR_ITALIC     = 1 << 2,
	ATTR_UNDERLINE  = 1 << 3,
	ATTR_BLINK      = 1 << 4,
	ATTR_REVERSE    = 1 << 5,
	ATTR_INVISIBLE  = 1 << 6,
	ATTR_STRUCK     = 1 << 7,
	ATTR_WRAP       = 1 << 8,
	ATTR_WIDE       = 1 << 9,
	ATTR_WDUMMY     = 1 << 10,
	ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
};

enum cursor_movement {
	CURSOR_SAVE,
	CURSOR_LOAD
};

enum cursor_state {
	CURSOR_DEFAULT  = 0,
	CURSOR_WRAPNEXT = 1,
	CURSOR_ORIGIN   = 2
};

enum term_mode {
	MODE_WRAP        = 1 << 0,
	MODE_INSERT      = 1 << 1,
	MODE_APPKEYPAD   = 1 << 2,
	MODE_ALTSCREEN   = 1 << 3,
	MODE_CRLF        = 1 << 4,
	MODE_MOUSEBTN    = 1 << 5,
	MODE_MOUSEMOTION = 1 << 6,
	MODE_REVERSE     = 1 << 7,
	MODE_KBDLOCK     = 1 << 8,
	MODE_HIDE        = 1 << 9,
	MODE_ECHO        = 1 << 10,
	MODE_APPCURSOR   = 1 << 11,
	MODE_MOUSESGR    = 1 << 12,
	MODE_8BIT        = 1 << 13,
	MODE_BLINK       = 1 << 14,
	MODE_FBLINK      = 1 << 15,
	MODE_FOCUS       = 1 << 16,
	MODE_MOUSEX10    = 1 << 17,
	MODE_MOUSEMANY   = 1 << 18,
	MODE_BRCKTPASTE  = 1 << 19,
	MODE_PRINT       = 1 << 20,
	MODE_UTF8        = 1 << 21,
	MODE_SIXEL       = 1 << 22,
	MODE_MOUSE       = MODE_MOUSEBTN|MODE_MOUSEMOTION|MODE_MOUSEX10\
	                  |MODE_MOUSEMANY,
};

enum charset {
	CS_GRAPHIC0,
	CS_GRAPHIC1,
	CS_UK,
	CS_USA,
	CS_MULTI,
	CS_GER,
	CS_FIN
};

enum escape_state {
	ESC_START      = 1,
	ESC_CSI        = 2,
	ESC_STR        = 4,  /* OSC, PM, APC */
	ESC_ALTCHARSET = 8,
	ESC_STR_END    = 16, /* a final string was encountered */
	ESC_TEST       = 32, /* Enter in test mode */
	ESC_UTF8       = 64,
	ESC_DCS        =128,
};

enum window_state {
	WIN_VISIBLE = 1,
	WIN_FOCUSED = 2
};

enum selection_mode {
	SEL_IDLE = 0,
	SEL_EMPTY = 1,
	SEL_READY = 2
};

enum selection_type {
	SEL_REGULAR = 1,
	SEL_RECTANGULAR = 2
};

enum selection_snap {
	SNAP_WORD = 1,
	SNAP_LINE = 2
};

typedef unsigned char uchar;
typedef unsigned int uint;
typedef unsigned long ulong;
typedef unsigned short ushort;

typedef uint_least32_t Rune;

typedef XftDraw *Draw;
typedef XftColor Color;

typedef struct {
	Rune u;           /* character code */
	ushort mode;      /* attribute flags */
	uint32_t fg;      /* foreground  */
	uint32_t bg;      /* background  */
} Glyph;

typedef Glyph *Line;

typedef struct {
	Glyph attr; /* current char attributes */
	int x;
	int y;
	char state;
} TCursor;

/* CSI Escape sequence structs */
/* ESC '[' [[ [<priv>] <arg> [;]] <mode> [<mode>]] */
typedef struct {
	char buf[ESC_BUF_SIZ]; /* raw string */
	int len;               /* raw string length */
	char priv;
	int arg[ESC_ARG_SIZ];
	int narg;              /* nb of args */
	char mode[2];
} CSIEscape;

/* STR Escape sequence structs */
/* ESC type [[ [<priv>] <arg> [;]] <mode>] ESC '\' */
typedef struct {
	char type;             /* ESC type ... */
	char buf[STR_BUF_SIZ]; /* raw string */
	int len;               /* raw string length */
	char *args[STR_ARG_SIZ];
	int narg;              /* nb of args */
} STREscape;

/* Purely graphic info */
typedef struct {
	Display *dpy;
	Colormap cmap;
	Window win;
	Drawable buf;
	Atom xembed, wmdeletewin, netwmname, netwmpid;
	XIM xim;
	XIC xic;
	Draw draw;
	Visual *vis;
	XSetWindowAttributes attrs;
	/* Here, we use the term *pointer* to differentiate the cursor
	 * one sees when hovering the mouse over the terminal from, e.g.,
	 * a green rectangle where text would be entered. */
	Cursor vpointer, bpointer; /* visible and hidden pointers */
	int pointerisvisible;
	int scr;
	int isfixed; /* is fixed geometry? */
	int l, t; /* left and top offset */
	int gm; /* geometry mask */
	int tw, th; /* tty width and height */
	int w, h; /* window width and height */
	int ch; /* char height */
	int cw; /* char width  */
	int depth; /*  bit depth */
	char state; /* focus, redraw, visible */
	int cursor; /* cursor style */
} XWindow;

typedef struct {
	uint b;
	uint mask;
	char *s;
} MouseShortcut;

typedef struct {
	KeySym k;
	uint mask;
	char *s;
	/* three valued logic variables: 0 indifferent, 1 on, -1 off */
	signed char appkey;    /* application keypad */
	signed char appcursor; /* application cursor */
	signed char crlf;      /* crlf mode          */
} Key;

typedef struct {
	int mode;
	int type;
	int snap;
	/*
	 * Selection variables:
	 * nb – normalized coordinates of the beginning of the selection
	 * ne – normalized coordinates of the end of the selection
	 * ob – original coordinates of the beginning of the selection
	 * oe – original coordinates of the end of the selection
	 */
	struct {
		int x, y;
	} nb, ne, ob, oe;

	char *primary, *clipboard;
	Atom xtarget;
	int alt;
	struct timespec tclick1;
	struct timespec tclick2;
} Selection;

typedef union {
	int i;
	uint ui;
	float f;
	const void *v;
} Arg;

typedef struct {
	uint b;
	uint mask;
	void (*func)(const Arg *);
	const Arg arg;
} MouseKey;

typedef struct {
	uint mod;
	KeySym keysym;
	void (*func)(const Arg *);
	const Arg arg;
} Shortcut;

/* function definitions used in config.h */
static void clipcopy(const Arg *);
static void clippaste(const Arg *);
static void kscrolldown(const Arg *);
static void kscrollup(const Arg *);
static void numlock(const Arg *);
static void selpaste(const Arg *);
static void xzoom(const Arg *);
static void xzoomabs(const Arg *);
static void xzoomreset(const Arg *);
static void printsel(const Arg *);
static void printscreen(const Arg *) ;
static void iso14755(const Arg *);
static void toggleprinter(const Arg *);
static void sendbreak(const Arg *);
static void externalpipe(const Arg *);

/* Config.h for applying patches and the configuration. */
#include "config.h"

/* Internal representation of the screen */
typedef struct {
	int row;      /* nb row */
	int col;      /* nb col */
	Line *line;   /* screen */
	Line *alt;    /* alternate screen */
	Line hist[histsize]; /* history buffer */
	int histi;    /* history index */
	int scr;      /* scroll back */
	int *dirty;  /* dirtyness of lines */
	XftGlyphFontSpec *specbuf; /* font spec buffer used for rendering */
	TCursor c;    /* cursor */
	int top;      /* top    scroll limit */
	int bot;      /* bottom scroll limit */
	int mode;     /* terminal mode flags */
	int esc;      /* escape state flags */
	char trantbl[4]; /* charset table translation */
	int charset;  /* current charset */
	int icharset; /* selected charset for sequence */
	int numlock; /* lock numbers in keyboard */
	int *tabs;
} Term;

/* Font structure */
typedef struct {
	int height;
	int width;
	int ascent;
	int descent;
	int badslant;
	int badweight;
	short lbearing;
	short rbearing;
	XftFont *match;
	FcFontSet *set;
	FcPattern *pattern;
} Font;

/* Drawing Context */
typedef struct {
	Color col[MAX(LEN(colorname), 256)];
	Font font, bfont, ifont, ibfont;
	GC gc;
} DC;

static void die(const char *, ...);
static void draw(void);
static void redraw(void);
static void drawregion(int, int, int, int);
static void execsh(void);
static void stty(void);
static void sigchld(int);
static void run(void);

static void csidump(void);
static void csihandle(void);
static void csiparse(void);
static void csireset(void);
static int eschandle(uchar);
static void strdump(void);
static void strhandle(void);
static void strparse(void);
static void strreset(void);

static int tattrset(int);
static void tprinter(char *, size_t);
static void tdumpsel(void);
static void tdumpline(int);
static void tdump(void);
static void tclearregion(int, int, int, int);
static void tcursor(int);
static void tdeletechar(int);
static void tdeleteline(int);
static void tinsertblank(int);
static void tinsertblankline(int);
static int tlinelen(int);
static void tmoveto(int, int);
static void tmoveato(int, int);
static void tnew(int, int);
static void tnewline(int);
static void tputtab(int);
static void tputc(Rune);
static void treset(void);
static void tresize(int, int);
static void tscrollup(int, int, int);
static void tscrolldown(int, int, int);
static void tsetattr(int *, int);
static void tsetchar(Rune, Glyph *, int, int);
static void tsetscroll(int, int);
static void tswapscreen(void);
static void tsetdirt(int, int);
static void tsetdirtattr(int);
static void tsetmode(int, int, int *, int);
static void tfulldirt(void);
static void techo(Rune);
static void tcontrolcode(uchar );
static void tdectest(char );
static void tdefutf8(char);
static int32_t tdefcolor(int *, int *, int);
static void tdeftran(char);
static inline int match(uint, uint);
static void ttynew(void);
static size_t ttyread(void);
static void ttyresize(void);
static void ttysend(char *, size_t);
static void ttywrite(const char *, size_t);
static void tstrsequence(uchar);

static inline ushort sixd_to_16bit(int);
static int xmakeglyphfontspecs(XftGlyphFontSpec *, const Glyph *, int, int, int);
static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
static void xdrawglyph(Glyph, int, int);
static void xhints(void);
static void xclear(int, int, int, int);
static void xdrawcursor(void);
static void xinit(void);
static void xloadcols(void);
static int xsetcolorname(int, const char *);
static int xgeommasktogravity(int);
static int xloadfont(Font *, FcPattern *);
static void xloadfonts(char *, double);
static void xsettitle(char *);
static void xresettitle(void);
static void xsetpointermotion(int);
static void xseturgency(int);
static void xsetsel(char *, Time);
static void xunloadfont(Font *);
static void xunloadfonts(void);
static void xresize(int, int);

static void expose(XEvent *);
static void visibility(XEvent *);
static void unmap(XEvent *);
static char *kmap(KeySym, uint);
static void kpress(XEvent *);
static void cmessage(XEvent *);
static void cresize(int, int);
static void resize(XEvent *);
static void focus(XEvent *);
static void brelease(XEvent *);
static void bpress(XEvent *);
static void bmotion(XEvent *);
static void propnotify(XEvent *);
static void selnotify(XEvent *);
static void selclear(XEvent *);
static void selrequest(XEvent *);

static void selinit(void);
static void selnormalize(void);
static inline int selected(int, int);
static char *getsel(void);
static void selcopy(Time);
static void selscroll(int, int);
static void selsnap(int *, int *, int);
static int x2col(int);
static int y2row(int);
static void getbuttoninfo(XEvent *);
static void mousereport(XEvent *);

static size_t utf8decode(char *, Rune *, size_t);
static Rune utf8decodebyte(char, size_t *);
static size_t utf8encode(Rune, char *);
static char utf8encodebyte(Rune, size_t);
static char *utf8strchr(char *s, Rune u);
static size_t utf8validate(Rune *, size_t);

static ssize_t xwrite(int, const char *, size_t);
static void *xmalloc(size_t);
static void *xrealloc(void *, size_t);
static char *xstrdup(char *);

static void usage(void);

static void (*handler[LASTEvent])(XEvent *) = {
	[KeyPress] = kpress,
	[ClientMessage] = cmessage,
	[ConfigureNotify] = resize,
	[VisibilityNotify] = visibility,
	[UnmapNotify] = unmap,
	[Expose] = expose,
	[FocusIn] = focus,
	[FocusOut] = focus,
	[MotionNotify] = bmotion,
	[ButtonPress] = bpress,
	[ButtonRelease] = brelease,
/*
 * Uncomment if you want the selection to disappear when you select something
 * different in another window.
 */
/*	[SelectionClear] = selclear, */
	[SelectionNotify] = selnotify,
/*
 * PropertyNotify is only turned on when there is some INCR transfer happening
 * for the selection retrieval.
 */
	[PropertyNotify] = propnotify,
	[SelectionRequest] = selrequest,
};

/* Globals */
static DC dc;
static XWindow xw;
static Term term;
static CSIEscape csiescseq;
static STREscape strescseq;
static int cmdfd;
static pid_t pid;
static Selection sel;
static int iofd = 1;
static char **opt_cmd  = NULL;
static char *opt_class = NULL;
static char *opt_embed = NULL;
static char *opt_font  = NULL;
static char *opt_io    = NULL;
static char *opt_line  = NULL;
static char *opt_name  = NULL;
static char *opt_title = NULL;
static int oldbutton   = 3; /* button event on startup: 3 = release */

static char *usedfont = NULL;
static double usedfontsize = 0;
static double defaultfontsize = 0;

static uchar utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
static uchar utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
static Rune utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
static Rune utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};

/* Font Ring Cache */
enum {
	FRC_NORMAL,
	FRC_ITALIC,
	FRC_BOLD,
	FRC_ITALICBOLD
};

typedef struct {
	XftFont *font;
	int flags;
	Rune unicodep;
} Fontcache;

/* Fontcache is an array now. A new font will be appended to the array. */
static Fontcache frc[16];
static int frclen = 0;

ssize_t
xwrite(int fd, const char *s, size_t len)
{
	size_t aux = len;
	ssize_t r;

	while (len > 0) {
		r = write(fd, s, len);
		if (r < 0)
			return r;
		len -= r;
		s += r;
	}

	return aux;
}

void *
xmalloc(size_t len)
{
	void *p = malloc(len);

	if (!p)
		die("Out of memory\n");

	return p;
}

void *
xrealloc(void *p, size_t len)
{
	if ((p = realloc(p, len)) == NULL)
		die("Out of memory\n");

	return p;
}

char *
xstrdup(char *s)
{
	if ((s = strdup(s)) == NULL)
		die("Out of memory\n");

	return s;
}

size_t
utf8decode(char *c, Rune *u, size_t clen)
{
	size_t i, j, len, type;
	Rune udecoded;

	*u = UTF_INVALID;
	if (!clen)
		return 0;
	udecoded = utf8decodebyte(c[0], &len);
	if (!BETWEEN(len, 1, UTF_SIZ))
		return 1;
	for (i = 1, j = 1; i < clen && j < len; ++i, ++j) {
		udecoded = (udecoded << 6) | utf8decodebyte(c[i], &type);
		if (type != 0)
			return j;
	}
	if (j < len)
		return 0;
	*u = udecoded;
	utf8validate(u, len);

	return len;
}

Rune
utf8decodebyte(char c, size_t *i)
{
	for (*i = 0; *i < LEN(utfmask); ++(*i))
		if (((uchar)c & utfmask[*i]) == utfbyte[*i])
			return (uchar)c & ~utfmask[*i];

	return 0;
}

size_t
utf8encode(Rune u, char *c)
{
	size_t len, i;

	len = utf8validate(&u, 0);
	if (len > UTF_SIZ)
		return 0;

	for (i = len - 1; i != 0; --i) {
		c[i] = utf8encodebyte(u, 0);
		u >>= 6;
	}
	c[0] = utf8encodebyte(u, len);

	return len;
}

char
utf8encodebyte(Rune u, size_t i)
{
	return utfbyte[i] | (u & ~utfmask[i]);
}

char *
utf8strchr(char *s, Rune u)
{
	Rune r;
	size_t i, j, len;

	len = strlen(s);
	for (i = 0, j = 0; i < len; i += j) {
		if (!(j = utf8decode(&s[i], &r, len - i)))
			break;
		if (r == u)
			return &(s[i]);
	}

	return NULL;
}

size_t
utf8validate(Rune *u, size_t i)
{
	if (!BETWEEN(*u, utfmin[i], utfmax[i]) || BETWEEN(*u, 0xD800, 0xDFFF))
		*u = UTF_INVALID;
	for (i = 1; *u > utfmax[i]; ++i)
		;

	return i;
}

void
selinit(void)
{
	clock_gettime(CLOCK_MONOTONIC, &sel.tclick1);
	clock_gettime(CLOCK_MONOTONIC, &sel.tclick2);
	sel.mode = SEL_IDLE;
	sel.snap = 0;
	sel.ob.x = -1;
	sel.primary = NULL;
	sel.clipboard = NULL;
	sel.xtarget = XInternAtom(xw.dpy, "UTF8_STRING", 0);
	if (sel.xtarget == None)
		sel.xtarget = XA_STRING;
}

int
x2col(int x)
{
	x -= borderpx;
	x /= xw.cw;

	return LIMIT(x, 0, term.col-1);
}

int
y2row(int y)
{
	y -= borderpx;
	y /= xw.ch;

	return LIMIT(y, 0, term.row-1);
}

int
tlinelen(int y)
{
	int i = term.col;

	if (TLINE(y)[i - 1].mode & ATTR_WRAP)
		return i;

	while (i > 0 && TLINE(y)[i - 1].u == ' ')
		--i;

	return i;
}

void
selnormalize(void)
{
	int i;

	if (sel.type == SEL_REGULAR && sel.ob.y != sel.oe.y) {
		sel.nb.x = sel.ob.y < sel.oe.y ? sel.ob.x : sel.oe.x;
		sel.ne.x = sel.ob.y < sel.oe.y ? sel.oe.x : sel.ob.x;
	} else {
		sel.nb.x = MIN(sel.ob.x, sel.oe.x);
		sel.ne.x = MAX(sel.ob.x, sel.oe.x);
	}
	sel.nb.y = MIN(sel.ob.y, sel.oe.y);
	sel.ne.y = MAX(sel.ob.y, sel.oe.y);

	selsnap(&sel.nb.x, &sel.nb.y, -1);
	selsnap(&sel.ne.x, &sel.ne.y, +1);

	/* expand selection over line breaks */
	if (sel.type == SEL_RECTANGULAR)
		return;
	i = tlinelen(sel.nb.y);
	if (i < sel.nb.x)
		sel.nb.x = i;
	if (tlinelen(sel.ne.y) <= sel.ne.x)
		sel.ne.x = term.col - 1;
}

int
selected(int x, int y)
{
	if (sel.mode == SEL_EMPTY)
		return 0;

	if (sel.type == SEL_RECTANGULAR)
		return BETWEEN(y, sel.nb.y, sel.ne.y)
		    && BETWEEN(x, sel.nb.x, sel.ne.x);

	return BETWEEN(y, sel.nb.y, sel.ne.y)
	    && (y != sel.nb.y || x >= sel.nb.x)
	    && (y != sel.ne.y || x <= sel.ne.x);
}

void
selsnap(int *x, int *y, int direction)
{
	int newx, newy, xt, yt;
	int delim, prevdelim;
	Glyph *gp, *prevgp;

	switch (sel.snap) {
	case SNAP_WORD:
		/*
		 * Snap around if the word wraps around at the end or
		 * beginning of a line.
		 */
		prevgp = &TLINE(*y)[*x];
		prevdelim = ISDELIM(prevgp->u);
		for (;;) {
			newx = *x + direction;
			newy = *y;
			if (!BETWEEN(newx, 0, term.col - 1)) {
				newy += direction;
				newx = (newx + term.col) % term.col;
				if (!BETWEEN(newy, 0, term.row - 1))
					break;

				if (direction > 0)
					yt = *y, xt = *x;
				else
					yt = newy, xt = newx;
				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
					break;
			}

			if (newx >= tlinelen(newy))
				break;

			gp = &TLINE(newy)[newx];
			delim = ISDELIM(gp->u);
			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
					|| (delim && gp->u != prevgp->u)))
				break;

			*x = newx;
			*y = newy;
			prevgp = gp;
			prevdelim = delim;
		}
		break;
	case SNAP_LINE:
		/*
		 * Snap around if the the previous line or the current one
		 * has set ATTR_WRAP at its end. Then the whole next or
		 * previous line will be selected.
		 */
		*x = (direction < 0) ? 0 : term.col - 1;
		if (direction < 0) {
			for (; *y > 0; *y += direction) {
				if (!(TLINE(*y-1)[term.col-1].mode
						& ATTR_WRAP)) {
					break;
				}
			}
		} else if (direction > 0) {
			for (; *y < term.row-1; *y += direction) {
				if (!(TLINE(*y)[term.col-1].mode
						& ATTR_WRAP)) {
					break;
				}
			}
		}
		break;
	}
}

void
getbuttoninfo(XEvent *e)
{
	int type;
	uint state = e->xbutton.state & ~(Button1Mask | forceselmod);

	sel.alt = IS_SET(MODE_ALTSCREEN);

	sel.oe.x = x2col(e->xbutton.x);
	sel.oe.y = y2row(e->xbutton.y);
	selnormalize();

	sel.type = SEL_REGULAR;
	for (type = 1; type < LEN(selmasks); ++type) {
		if (match(selmasks[type], state)) {
			sel.type = type;
			break;
		}
	}
}

void
mousereport(XEvent *e)
{
	int x = x2col(e->xbutton.x), y = y2row(e->xbutton.y),
	    button = e->xbutton.button, state = e->xbutton.state,
	    len;
	char buf[40];
	static int ox, oy;

	/* from urxvt */
	if (e->xbutton.type == MotionNotify) {
		if (x == ox && y == oy)
			return;
		if (!IS_SET(MODE_MOUSEMOTION) && !IS_SET(MODE_MOUSEMANY))
			return;
		/* MOUSE_MOTION: no reporting if no button is pressed */
		if (IS_SET(MODE_MOUSEMOTION) && oldbutton == 3)
			return;

		button = oldbutton + 32;
		ox = x;
		oy = y;
	} else {
		if (!IS_SET(MODE_MOUSESGR) && e->xbutton.type == ButtonRelease) {
			button = 3;
		} else {
			button -= Button1;
			if (button >= 3)
				button += 64 - 3;
		}
		if (e->xbutton.type == ButtonPress) {
			oldbutton = button;
			ox = x;
			oy = y;
		} else if (e->xbutton.type == ButtonRelease) {
			oldbutton = 3;
			/* MODE_MOUSEX10: no button release reporting */
			if (IS_SET(MODE_MOUSEX10))
				return;
			if (button == 64 || button == 65)
				return;
		}
	}

	if (!IS_SET(MODE_MOUSEX10)) {
		button += ((state & ShiftMask  ) ? 4  : 0)
			+ ((state & Mod4Mask   ) ? 8  : 0)
			+ ((state & ControlMask) ? 16 : 0);
	}

	if (IS_SET(MODE_MOUSESGR)) {
		len = snprintf(buf, sizeof(buf), "\033[<%d;%d;%d%c",
				button, x+1, y+1,
				e->xbutton.type == ButtonRelease ? 'm' : 'M');
	} else if (x < 223 && y < 223) {
		len = snprintf(buf, sizeof(buf), "\033[M%c%c%c",
				32+button, 32+x+1, 32+y+1);
	} else {
		return;
	}

	ttywrite(buf, len);
}

void
bpress(XEvent *e)
{
	struct timespec now;
	MouseShortcut *ms;
	MouseKey *mk;

	if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forceselmod)) {
		mousereport(e);
		return;
	}

	if (IS_SET(MODE_ALTSCREEN))
		for (ms = mshortcuts; ms < mshortcuts + LEN(mshortcuts); ms++) {
			if (e->xbutton.button == ms->b
					&& match(ms->mask, e->xbutton.state)) {
				ttysend(ms->s, strlen(ms->s));
				return;
			}
		}

	for (mk = mkeys; mk < mkeys + LEN(mkeys); mk++) {
		if (e->xbutton.button == mk->b
				&& match(mk->mask, e->xbutton.state)) {
			mk->func(&mk->arg);
			return;
		}
	}

	if (e->xbutton.button == Button1) {
		clock_gettime(CLOCK_MONOTONIC, &now);

		/* Clear previous selection, logically and visually. */
		selclear(NULL);
		sel.mode = SEL_EMPTY;
		sel.type = SEL_REGULAR;
		sel.oe.x = sel.ob.x = x2col(e->xbutton.x);
		sel.oe.y = sel.ob.y = y2row(e->xbutton.y);

		/*
		 * If the user clicks below predefined timeouts specific
		 * snapping behaviour is exposed.
		 */
		if (TIMEDIFF(now, sel.tclick2) <= tripleclicktimeout) {
			sel.snap = SNAP_LINE;
		} else if (TIMEDIFF(now, sel.tclick1) <= doubleclicktimeout) {
			sel.snap = SNAP_WORD;
		} else {
			sel.snap = 0;
		}
		selnormalize();

		if (sel.snap != 0)
			sel.mode = SEL_READY;
		tsetdirt(sel.nb.y, sel.ne.y);
		sel.tclick2 = sel.tclick1;
		sel.tclick1 = now;
	}
}

char *
getsel(void)
{
	char *str, *ptr;
	int y, bufsize, lastx, linelen;
	Glyph *gp, *last;

	if (sel.ob.x == -1)
		return NULL;

	bufsize = (term.col+1) * (sel.ne.y-sel.nb.y+1) * UTF_SIZ;
	ptr = str = xmalloc(bufsize);

	/* append every set & selected glyph to the selection */
	for (y = sel.nb.y; y <= sel.ne.y; y++) {
		if ((linelen = tlinelen(y)) == 0) {
			*ptr++ = '\n';
			continue;
		}

		if (sel.type == SEL_RECTANGULAR) {
			gp = &TLINE(y)[sel.nb.x];
			lastx = sel.ne.x;
		} else {
			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
		}
		last = &TLINE(y)[MIN(lastx, linelen-1)];
		while (last >= gp && last->u == ' ')
			--last;

		for ( ; gp <= last; ++gp) {
			if (gp->mode & ATTR_WDUMMY)
				continue;

			ptr += utf8encode(gp->u, ptr);
		}

		/*
		 * Copy and pasting of line endings is inconsistent
		 * in the inconsistent terminal and GUI world.
		 * The best solution seems like to produce '\n' when
		 * something is copied from st and convert '\n' to
		 * '\r', when something to be pasted is received by
		 * st.
		 * FIXME: Fix the computer world.
		 */
		if ((y < sel.ne.y || lastx >= linelen) && !(last->mode & ATTR_WRAP))
			*ptr++ = '\n';
	}
	*ptr = 0;
	return str;
}

void
selcopy(Time t)
{
	xsetsel(getsel(), t);
}

void
propnotify(XEvent *e)
{
	XPropertyEvent *xpev;
	Atom clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);

	xpev = &e->xproperty;
	if (xpev->state == PropertyNewValue &&
			(xpev->atom == XA_PRIMARY ||
			 xpev->atom == clipboard)) {
		selnotify(e);
	}
}

void
selnotify(XEvent *e)
{
	ulong nitems, ofs, rem;
	int format;
	uchar *data, *last, *repl;
	Atom type, incratom, property;

	incratom = XInternAtom(xw.dpy, "INCR", 0);

	ofs = 0;
	if (e->type == SelectionNotify) {
		property = e->xselection.property;
	} else if(e->type == PropertyNotify) {
		property = e->xproperty.atom;
	} else {
		return;
	}
	if (property == None)
		return;

	do {
		if (XGetWindowProperty(xw.dpy, xw.win, property, ofs,
					BUFSIZ/4, False, AnyPropertyType,
					&type, &format, &nitems, &rem,
					&data)) {
			fprintf(stderr, "Clipboard allocation failed\n");
			return;
		}

		if (e->type == PropertyNotify && nitems == 0 && rem == 0) {
			/*
			 * If there is some PropertyNotify with no data, then
			 * this is the signal of the selection owner that all
			 * data has been transferred. We won't need to receive
			 * PropertyNotify events anymore.
			 */
			MODBIT(xw.attrs.event_mask, 0, PropertyChangeMask);
			XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
					&xw.attrs);
		}

		if (type == incratom) {
			/*
			 * Activate the PropertyNotify events so we receive
			 * when the selection owner does send us the next
			 * chunk of data.
			 */
			MODBIT(xw.attrs.event_mask, 1, PropertyChangeMask);
			XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
					&xw.attrs);

			/*
			 * Deleting the property is the transfer start signal.
			 */
			XDeleteProperty(xw.dpy, xw.win, (int)property);
			continue;
		}

		/*
		 * As seen in getsel:
		 * Line endings are inconsistent in the terminal and GUI world
		 * copy and pasting. When receiving some selection data,
		 * replace all '\n' with '\r'.
		 * FIXME: Fix the computer world.
		 */
		repl = data;
		last = data + nitems * format / 8;
		while ((repl = memchr(repl, '\n', last - repl))) {
			*repl++ = '\r';
		}

		if (IS_SET(MODE_BRCKTPASTE) && ofs == 0)
			ttywrite("\033[200~", 6);
		ttysend((char *)data, nitems * format / 8);
		if (IS_SET(MODE_BRCKTPASTE) && rem == 0)
			ttywrite("\033[201~", 6);
		XFree(data);
		/* number of 32-bit chunks returned */
		ofs += nitems * format / 32;
	} while (rem > 0);

	/*
	 * Deleting the property again tells the selection owner to send the
	 * next data chunk in the property.
	 */
	XDeleteProperty(xw.dpy, xw.win, (int)property);
}

void
selpaste(const Arg *dummy)
{
	XConvertSelection(xw.dpy, XA_PRIMARY, sel.xtarget, XA_PRIMARY,
			xw.win, CurrentTime);
}

void
clipcopy(const Arg *dummy)
{
	Atom clipboard;

	if (sel.clipboard != NULL)
		free(sel.clipboard);

	if (sel.primary != NULL) {
		sel.clipboard = xstrdup(sel.primary);
		clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
		XSetSelectionOwner(xw.dpy, clipboard, xw.win, CurrentTime);
	}
}

void
clippaste(const Arg *dummy)
{
	Atom clipboard;

	clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
	XConvertSelection(xw.dpy, clipboard, sel.xtarget, clipboard,
			xw.win, CurrentTime);
}

void
selclear(XEvent *e)
{
	if (sel.ob.x == -1)
		return;
	sel.mode = SEL_IDLE;
	sel.ob.x = -1;
	tsetdirt(sel.nb.y, sel.ne.y);
}

void
selrequest(XEvent *e)
{
	XSelectionRequestEvent *xsre;
	XSelectionEvent xev;
	Atom xa_targets, string, clipboard;
	char *seltext;

	xsre = (XSelectionRequestEvent *) e;
	xev.type = SelectionNotify;
	xev.requestor = xsre->requestor;
	xev.selection = xsre->selection;
	xev.target = xsre->target;
	xev.time = xsre->time;
	if (xsre->property == None)
		xsre->property = xsre->target;

	/* reject */
	xev.property = None;

	xa_targets = XInternAtom(xw.dpy, "TARGETS", 0);
	if (xsre->target == xa_targets) {
		/* respond with the supported type */
		string = sel.xtarget;
		XChangeProperty(xsre->display, xsre->requestor, xsre->property,
				XA_ATOM, 32, PropModeReplace,
				(uchar *) &string, 1);
		xev.property = xsre->property;
	} else if (xsre->target == sel.xtarget || xsre->target == XA_STRING) {
		/*
		 * xith XA_STRING non ascii characters may be incorrect in the
		 * requestor. It is not our problem, use utf8.
		 */
		clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
		if (xsre->selection == XA_PRIMARY) {
			seltext = sel.primary;
		} else if (xsre->selection == clipboard) {
			seltext = sel.clipboard;
		} else {
			fprintf(stderr,
				"Unhandled clipboard selection 0x%lx\n",
				xsre->selection);
			return;
		}
		if (seltext != NULL) {
			XChangeProperty(xsre->display, xsre->requestor,
					xsre->property, xsre->target,
					8, PropModeReplace,
					(uchar *)seltext, strlen(seltext));
			xev.property = xsre->property;
		}
	}

	/* all done, send a notification to the listener */
	if (!XSendEvent(xsre->display, xsre->requestor, 1, 0, (XEvent *) &xev))
		fprintf(stderr, "Error sending SelectionNotify event\n");
}

void
xsetsel(char *str, Time t)
{
	free(sel.primary);
	sel.primary = str;

	XSetSelectionOwner(xw.dpy, XA_PRIMARY, xw.win, t);
	if (XGetSelectionOwner(xw.dpy, XA_PRIMARY) != xw.win)
		selclear(0);
}

void
brelease(XEvent *e)
{
	if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forceselmod)) {
		mousereport(e);
		return;
	}

	if (e->xbutton.button == Button2) {
		selpaste(NULL);
	} else if (e->xbutton.button == Button1) {
		if (sel.mode == SEL_READY) {
			getbuttoninfo(e);
			selcopy(e->xbutton.time);
		} else
			selclear(NULL);
		sel.mode = SEL_IDLE;
		tsetdirt(sel.nb.y, sel.ne.y);
	}
}

void
bmotion(XEvent *e)
{
	int oldey, oldex, oldsby, oldsey;

	if(!xw.pointerisvisible) {
		XDefineCursor(xw.dpy, xw.win, xw.vpointer);
		xw.pointerisvisible = 1;
		if(!IS_SET(MODE_MOUSEMANY))
			xsetpointermotion(0);
	}

	if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forceselmod)) {
		mousereport(e);
		return;
	}

	if (!sel.mode)
		return;

	sel.mode = SEL_READY;
	oldey = sel.oe.y;
	oldex = sel.oe.x;
	oldsby = sel.nb.y;
	oldsey = sel.ne.y;
	getbuttoninfo(e);

	if (oldey != sel.oe.y || oldex != sel.oe.x)
		tsetdirt(MIN(sel.nb.y, oldsby), MAX(sel.ne.y, oldsey));
}

void
die(const char *errstr, ...)
{
	va_list ap;

	va_start(ap, errstr);
	vfprintf(stderr, errstr, ap);
	va_end(ap);
	exit(1);
}

void
execsh(void)
{
	char **args, *sh, *prog;
	const struct passwd *pw;
	char buf[sizeof(long) * 8 + 1];

	errno = 0;
	if ((pw = getpwuid(getuid())) == NULL) {
		if (errno)
			die("getpwuid:%s\n", strerror(errno));
		else
			die("who are you?\n");
	}

	if ((sh = getenv("SHELL")) == NULL)
		sh = (pw->pw_shell[0]) ? pw->pw_shell : shell;

	if (opt_cmd)
		prog = opt_cmd[0];
	else if (utmp)
		prog = utmp;
	else
		prog = sh;
	args = (opt_cmd) ? opt_cmd : (char *[]) {prog, NULL};

	snprintf(buf, sizeof(buf), "%lu", xw.win);

	unsetenv("COLUMNS");
	unsetenv("LINES");
	unsetenv("TERMCAP");
	setenv("LOGNAME", pw->pw_name, 1);
	setenv("USER", pw->pw_name, 1);
	setenv("SHELL", sh, 1);
	setenv("HOME", pw->pw_dir, 1);
	setenv("TERM", termname, 1);
	setenv("WINDOWID", buf, 1);

	signal(SIGCHLD, SIG_DFL);
	signal(SIGHUP, SIG_DFL);
	signal(SIGINT, SIG_DFL);
	signal(SIGQUIT, SIG_DFL);
	signal(SIGTERM, SIG_DFL);
	signal(SIGALRM, SIG_DFL);

	execvp(prog, args);
	_exit(1);
}

void
sigchld(int a)
{
	int stat;
	pid_t p;

	if ((p = waitpid(pid, &stat, WNOHANG)) < 0)
		die("Waiting for pid %hd failed: %s\n", pid, strerror(errno));

	if (pid != p)
		return;

	if (!WIFEXITED(stat) || WEXITSTATUS(stat))
		die("child finished with error '%d'\n", stat);
	exit(0);
}


void
stty(void)
{
	char cmd[_POSIX_ARG_MAX], **p, *q, *s;
	size_t n, siz;

	if ((n = strlen(stty_args)) > sizeof(cmd)-1)
		die("incorrect stty parameters\n");
	memcpy(cmd, stty_args, n);
	q = cmd + n;
	siz = sizeof(cmd) - n;
	for (p = opt_cmd; p && (s = *p); ++p) {
		if ((n = strlen(s)) > siz-1)
			die("stty parameter length too long\n");
		*q++ = ' ';
		memcpy(q, s, n);
		q += n;
		siz -= n + 1;
	}
	*q = '\0';
	if (system(cmd) != 0)
	    perror("Couldn't call stty");
}

void
ttynew(void)
{
	int m, s;
	struct winsize w = {term.row, term.col, 0, 0};

	if (opt_io) {
		term.mode |= MODE_PRINT;
		iofd = (!strcmp(opt_io, "-")) ?
			  1 : open(opt_io, O_WRONLY | O_CREAT, 0666);
		if (iofd < 0) {
			fprintf(stderr, "Error opening %s:%s\n",
				opt_io, strerror(errno));
		}
	}

	if (opt_line) {
		if ((cmdfd = open(opt_line, O_RDWR)) < 0)
			die("open line failed: %s\n", strerror(errno));
		dup2(cmdfd, 0);
		stty();
		return;
	}

	/* seems to work fine on linux, openbsd and freebsd */
	if (openpty(&m, &s, NULL, NULL, &w) < 0)
		die("openpty failed: %s\n", strerror(errno));

	switch (pid = fork()) {
	case -1:
		die("fork failed\n");
		break;
	case 0:
		close(iofd);
		setsid(); /* create a new process group */
		dup2(s, 0);
		dup2(s, 1);
		dup2(s, 2);
		if (ioctl(s, TIOCSCTTY, NULL) < 0)
			die("ioctl TIOCSCTTY failed: %s\n", strerror(errno));
		close(s);
		close(m);
		execsh();
		break;
	default:
		close(s);
		cmdfd = m;
		signal(SIGCHLD, sigchld);
		break;
	}
}

size_t
ttyread(void)
{
	static char buf[BUFSIZ];
	static int buflen = 0;
	char *ptr;
	int charsize; /* size of utf8 char in bytes */
	Rune unicodep;
	int ret;

	/* append read bytes to unprocessed bytes */
	if ((ret = read(cmdfd, buf+buflen, LEN(buf)-buflen)) < 0)
		die("Couldn't read from shell: %s\n", strerror(errno));

	buflen += ret;
	ptr = buf;

	for (;;) {
		if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
			/* process a complete utf8 char */
			charsize = utf8decode(ptr, &unicodep, buflen);
			if (charsize == 0)
				break;
			tputc(unicodep);
			ptr += charsize;
			buflen -= charsize;

		} else {
			if (buflen <= 0)
				break;
			tputc(*ptr++ & 0xFF);
			buflen--;
		}
	}
	/* keep any uncomplete utf8 char for the next call */
	if (buflen > 0)
		memmove(buf, ptr, buflen);

	if (term.scr > 0 && term.scr < histsize-1)
		term.scr++;

	return ret;
}

void
ttywrite(const char *s, size_t n)
{
	fd_set wfd, rfd;
	ssize_t r;
	size_t lim = 256;
	Arg arg = (Arg){ .i = term.scr };

	kscrolldown(&arg);

	/*
	 * Remember that we are using a pty, which might be a modem line.
	 * Writing too much will clog the line. That's why we are doing this
	 * dance.
	 * FIXME: Migrate the world to Plan 9.
	 */
	while (n > 0) {
		FD_ZERO(&wfd);
		FD_ZERO(&rfd);
		FD_SET(cmdfd, &wfd);
		FD_SET(cmdfd, &rfd);

		/* Check if we can write. */
		if (pselect(cmdfd+1, &rfd, &wfd, NULL, NULL, NULL) < 0) {
			if (errno == EINTR)
				continue;
			die("select failed: %s\n", strerror(errno));
		}
		if (FD_ISSET(cmdfd, &wfd)) {
			/*
			 * Only write the bytes written by ttywrite() or the
			 * default of 256. This seems to be a reasonable value
			 * for a serial line. Bigger values might clog the I/O.
			 */
			if ((r = write(cmdfd, s, (n < lim)? n : lim)) < 0)
				goto write_error;
			if (r < n) {
				/*
				 * We weren't able to write out everything.
				 * This means the buffer is getting full
				 * again. Empty it.
				 */
				if (n < lim)
					lim = ttyread();
				n -= r;
				s += r;
			} else {
				/* All bytes have been written. */
				break;
			}
		}
		if (FD_ISSET(cmdfd, &rfd))
			lim = ttyread();
	}
	return;

write_error:
	die("write error on tty: %s\n", strerror(errno));
}

void
ttysend(char *s, size_t n)
{
	int len;
	char *t, *lim;
	Rune u;

	ttywrite(s, n);
	if (!IS_SET(MODE_ECHO))
		return;

	lim = &s[n];
	for (t = s; t < lim; t += len) {
		if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
			len = utf8decode(t, &u, n);
		} else {
			u = *t & 0xFF;
			len = 1;
		}
		if (len <= 0)
			break;
		techo(u);
		n -= len;
	}
}

void
ttyresize(void)
{
	struct winsize w;

	w.ws_row = term.row;
	w.ws_col = term.col;
	w.ws_xpixel = xw.tw;
	w.ws_ypixel = xw.th;
	if (ioctl(cmdfd, TIOCSWINSZ, &w) < 0)
		fprintf(stderr, "Couldn't set window size: %s\n", strerror(errno));
}

int
tattrset(int attr)
{
	int i, j;

	for (i = 0; i < term.row-1; i++) {
		for (j = 0; j < term.col-1; j++) {
			if (term.line[i][j].mode & attr)
				return 1;
		}
	}

	return 0;
}

void
tsetdirt(int top, int bot)
{
	int i;

	LIMIT(top, 0, term.row-1);
	LIMIT(bot, 0, term.row-1);

	for (i = top; i <= bot; i++)
		term.dirty[i] = 1;
}

void
tsetdirtattr(int attr)
{
	int i, j;

	for (i = 0; i < term.row-1; i++) {
		for (j = 0; j < term.col-1; j++) {
			if (term.line[i][j].mode & attr) {
				tsetdirt(i, i);
				break;
			}
		}
	}
}

void
tfulldirt(void)
{
	tsetdirt(0, term.row-1);
}

void
tcursor(int mode)
{
	static TCursor c[2];
	int alt = IS_SET(MODE_ALTSCREEN);

	if (mode == CURSOR_SAVE) {
		c[alt] = term.c;
	} else if (mode == CURSOR_LOAD) {
		term.c = c[alt];
		tmoveto(c[alt].x, c[alt].y);
	}
}

void
treset(void)
{
	uint i;

	term.c = (TCursor){{
		.mode = ATTR_NULL,
		.fg = defaultfg,
		.bg = defaultbg
	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};

	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
	for (i = tabspaces; i < term.col; i += tabspaces)
		term.tabs[i] = 1;
	term.top = 0;
	term.bot = term.row - 1;
	term.mode = MODE_WRAP|MODE_UTF8;
	memset(term.trantbl, CS_USA, sizeof(term.trantbl));
	term.charset = 0;

	for (i = 0; i < 2; i++) {
		tmoveto(0, 0);
		tcursor(CURSOR_SAVE);
		tclearregion(0, 0, term.col-1, term.row-1);
		tswapscreen();
	}
}

void
tnew(int col, int row)
{
	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
	tresize(col, row);
	term.numlock = 1;

	treset();
}

void
tswapscreen(void)
{
	Line *tmp = term.line;

	term.line = term.alt;
	term.alt = tmp;
	term.mode ^= MODE_ALTSCREEN;
	tfulldirt();
}

void
kscrolldown(const Arg* a)
{
	int n = a->i;

	if (n < 0)
		n = term.row + n;

	if (n > term.scr)
		n = term.scr;

	if (term.scr > 0) {
		term.scr -= n;
		selscroll(0, -n);
		tfulldirt();
	}
}

void
kscrollup(const Arg* a)
{
	int n = a->i;

	if (n < 0)
		n = term.row + n;

	if (term.scr <= histsize - n) {
		term.scr += n;
		selscroll(0, n);
		tfulldirt();
	}
}

void
tscrolldown(int orig, int n, int copyhist)
{
	int i;
	Line temp;

	LIMIT(n, 0, term.bot-orig+1);

	if (copyhist) {
		term.histi = (term.histi - 1 + histsize) % histsize;
		temp = term.hist[term.histi];
		term.hist[term.histi] = term.line[term.bot];
		term.line[term.bot] = temp;
	}

	tsetdirt(orig, term.bot-n);
	tclearregion(0, term.bot-n+1, term.col-1, term.bot);

	for (i = term.bot; i >= orig+n; i--) {
		temp = term.line[i];
		term.line[i] = term.line[i-n];
		term.line[i-n] = temp;
	}

	selscroll(orig, n);
}

void
tscrollup(int orig, int n, int copyhist)
{
	int i;
	Line temp;

	LIMIT(n, 0, term.bot-orig+1);

	if (copyhist) {
		term.histi = (term.histi + 1) % histsize;
		temp = term.hist[term.histi];
		term.hist[term.histi] = term.line[orig];
		term.line[orig] = temp;
	}

	tclearregion(0, orig, term.col-1, orig+n-1);
	tsetdirt(orig+n, term.bot);

	for (i = orig; i <= term.bot-n; i++) {
		temp = term.line[i];
		term.line[i] = term.line[i+n];
		term.line[i+n] = temp;
	}

	selscroll(orig, -n);
}

void
selscroll(int orig, int n)
{
	if (sel.ob.x == -1)
		return;

	if (BETWEEN(sel.ob.y, orig, term.bot) || BETWEEN(sel.oe.y, orig, term.bot)) {
		if ((sel.ob.y += n) > term.bot || (sel.oe.y += n) < term.top) {
			selclear(NULL);
			return;
		}
		if (sel.type == SEL_RECTANGULAR) {
			if (sel.ob.y < term.top)
				sel.ob.y = term.top;
			if (sel.oe.y > term.bot)
				sel.oe.y = term.bot;
		} else {
			if (sel.ob.y < term.top) {
				sel.ob.y = term.top;
				sel.ob.x = 0;
			}
			if (sel.oe.y > term.bot) {
				sel.oe.y = term.bot;
				sel.oe.x = term.col;
			}
		}
		selnormalize();
	}
}

void
tnewline(int first_col)
{
	int y = term.c.y;

	if (y == term.bot) {
		tscrollup(term.top, 1, 1);
	} else {
		y++;
	}
	tmoveto(first_col ? 0 : term.c.x, y);
}

void
csiparse(void)
{
	char *p = csiescseq.buf, *np;
	long int v;

	csiescseq.narg = 0;
	if (*p == '?') {
		csiescseq.priv = 1;
		p++;
	}

	csiescseq.buf[csiescseq.len] = '\0';
	while (p < csiescseq.buf+csiescseq.len) {
		np = NULL;
		v = strtol(p, &np, 10);
		if (np == p)
			v = 0;
		if (v == LONG_MAX || v == LONG_MIN)
			v = -1;
		csiescseq.arg[csiescseq.narg++] = v;
		p = np;
		if (*p != ';' || csiescseq.narg == ESC_ARG_SIZ)
			break;
		p++;
	}
	csiescseq.mode[0] = *p++;
	csiescseq.mode[1] = (p < csiescseq.buf+csiescseq.len) ? *p : '\0';
}

/* for absolute user moves, when decom is set */
void
tmoveato(int x, int y)
{
	tmoveto(x, y + ((term.c.state & CURSOR_ORIGIN) ? term.top: 0));
}

void
tmoveto(int x, int y)
{
	int miny, maxy;

	if (term.c.state & CURSOR_ORIGIN) {
		miny = term.top;
		maxy = term.bot;
	} else {
		miny = 0;
		maxy = term.row - 1;
	}
	term.c.state &= ~CURSOR_WRAPNEXT;
	term.c.x = LIMIT(x, 0, term.col-1);
	term.c.y = LIMIT(y, miny, maxy);
}

void
tsetchar(Rune u, Glyph *attr, int x, int y)
{
	static char *vt100_0[62] = { /* 0x41 - 0x7e */
		"↑", "↓", "→", "←", "█", "▚", "☃", /* A - G */
		0, 0, 0, 0, 0, 0, 0, 0, /* H - O */
		0, 0, 0, 0, 0, 0, 0, 0, /* P - W */
		0, 0, 0, 0, 0, 0, 0, " ", /* X - _ */
		"◆", "▒", "␉", "␌", "␍", "␊", "°", "±", /* ` - g */
		"␤", "␋", "┘", "┐", "┌", "└", "┼", "⎺", /* h - o */
		"⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
		"│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
	};

	/*
	 * The table is proudly stolen from rxvt.
	 */
	if (term.trantbl[term.charset] == CS_GRAPHIC0 &&
	   BETWEEN(u, 0x41, 0x7e) && vt100_0[u - 0x41])
		utf8decode(vt100_0[u - 0x41], &u, UTF_SIZ);

	if (term.line[y][x].mode & ATTR_WIDE) {
		if (x+1 < term.col) {
			term.line[y][x+1].u = ' ';
			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
		}
	} else if (term.line[y][x].mode & ATTR_WDUMMY) {
		term.line[y][x-1].u = ' ';
		term.line[y][x-1].mode &= ~ATTR_WIDE;
	}

	term.dirty[y] = 1;
	term.line[y][x] = *attr;
	term.line[y][x].u = u;
}

void
tclearregion(int x1, int y1, int x2, int y2)
{
	int x, y, temp;
	Glyph *gp;

	if (x1 > x2)
		temp = x1, x1 = x2, x2 = temp;
	if (y1 > y2)
		temp = y1, y1 = y2, y2 = temp;

	LIMIT(x1, 0, term.col-1);
	LIMIT(x2, 0, term.col-1);
	LIMIT(y1, 0, term.row-1);
	LIMIT(y2, 0, term.row-1);

	for (y = y1; y <= y2; y++) {
		term.dirty[y] = 1;
		for (x = x1; x <= x2; x++) {
			gp = &term.line[y][x];
			if (selected(x, y))
				selclear(NULL);
			gp->fg = term.c.attr.fg;
			gp->bg = term.c.attr.bg;
			gp->mode = 0;
			gp->u = ' ';
		}
	}
}

void
tdeletechar(int n)
{
	int dst, src, size;
	Glyph *line;

	LIMIT(n, 0, term.col - term.c.x);

	dst = term.c.x;
	src = term.c.x + n;
	size = term.col - src;
	line = term.line[term.c.y];

	memmove(&line[dst], &line[src], size * sizeof(Glyph));
	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
}

void
tinsertblank(int n)
{
	int dst, src, size;
	Glyph *line;

	LIMIT(n, 0, term.col - term.c.x);

	dst = term.c.x + n;
	src = term.c.x;
	size = term.col - dst;
	line = term.line[term.c.y];

	memmove(&line[dst], &line[src], size * sizeof(Glyph));
	tclearregion(src, term.c.y, dst - 1, term.c.y);
}

void
tinsertblankline(int n)
{
	if (BETWEEN(term.c.y, term.top, term.bot))
		tscrolldown(term.c.y, n, 0);
}

void
tdeleteline(int n)
{
	if (BETWEEN(term.c.y, term.top, term.bot))
		tscrollup(term.c.y, n, 0);
}

int32_t
tdefcolor(int *attr, int *npar, int l)
{
	int32_t idx = -1;
	uint r, g, b;

	switch (attr[*npar + 1]) {
	case 2: /* direct color in RGB space */
		if (*npar + 4 >= l) {
			fprintf(stderr,
				"erresc(38): Incorrect number of parameters (%d)\n",
				*npar);
			break;
		}
		r = attr[*npar + 2];
		g = attr[*npar + 3];
		b = attr[*npar + 4];
		*npar += 4;
		if (!BETWEEN(r, 0, 255) || !BETWEEN(g, 0, 255) || !BETWEEN(b, 0, 255))
			fprintf(stderr, "erresc: bad rgb color (%u,%u,%u)\n",
				r, g, b);
		else
			idx = TRUECOLOR(r, g, b);
		break;
	case 5: /* indexed color */
		if (*npar + 2 >= l) {
			fprintf(stderr,
				"erresc(38): Incorrect number of parameters (%d)\n",
				*npar);
			break;
		}
		*npar += 2;
		if (!BETWEEN(attr[*npar], 0, 255))
			fprintf(stderr, "erresc: bad fgcolor %d\n", attr[*npar]);
		else
			idx = attr[*npar];
		break;
	case 0: /* implemented defined (only foreground) */
	case 1: /* transparent */
	case 3: /* direct color in CMY space */
	case 4: /* direct color in CMYK space */
	default:
		fprintf(stderr,
		        "erresc(38): gfx attr %d unknown\n", attr[*npar]);
		break;
	}

	return idx;
}

void
tsetattr(int *attr, int l)
{
	int i;
	int32_t idx;

	for (i = 0; i < l; i++) {
		switch (attr[i]) {
		case 0:
			term.c.attr.mode &= ~(
				ATTR_BOLD       |
				ATTR_FAINT      |
				ATTR_ITALIC     |
				ATTR_UNDERLINE  |
				ATTR_BLINK      |
				ATTR_REVERSE    |
				ATTR_INVISIBLE  |
				ATTR_STRUCK     );
			term.c.attr.fg = defaultfg;
			term.c.attr.bg = defaultbg;
			break;
		case 1:
			term.c.attr.mode |= ATTR_BOLD;
			break;
		case 2:
			term.c.attr.mode |= ATTR_FAINT;
			break;
		case 3:
			term.c.attr.mode |= ATTR_ITALIC;
			break;
		case 4:
			term.c.attr.mode |= ATTR_UNDERLINE;
			break;
		case 5: /* slow blink */
			/* FALLTHROUGH */
		case 6: /* rapid blink */
			term.c.attr.mode |= ATTR_BLINK;
			break;
		case 7:
			term.c.attr.mode |= ATTR_REVERSE;
			break;
		case 8:
			term.c.attr.mode |= ATTR_INVISIBLE;
			break;
		case 9:
			term.c.attr.mode |= ATTR_STRUCK;
			break;
		case 22:
			term.c.attr.mode &= ~(ATTR_BOLD | ATTR_FAINT);
			break;
		case 23:
			term.c.attr.mode &= ~ATTR_ITALIC;
			break;
		case 24:
			term.c.attr.mode &= ~ATTR_UNDERLINE;
			break;
		case 25:
			term.c.attr.mode &= ~ATTR_BLINK;
			break;
		case 27:
			term.c.attr.mode &= ~ATTR_REVERSE;
			break;
		case 28:
			term.c.attr.mode &= ~ATTR_INVISIBLE;
			break;
		case 29:
			term.c.attr.mode &= ~ATTR_STRUCK;
			break;
		case 38:
			if ((idx = tdefcolor(attr, &i, l)) >= 0)
				term.c.attr.fg = idx;
			break;
		case 39:
			term.c.attr.fg = defaultfg;
			break;
		case 48:
			if ((idx = tdefcolor(attr, &i, l)) >= 0)
				term.c.attr.bg = idx;
			break;
		case 49:
			term.c.attr.bg = defaultbg;
			break;
		default:
			if (BETWEEN(attr[i], 30, 37)) {
				term.c.attr.fg = attr[i] - 30;
			} else if (BETWEEN(attr[i], 40, 47)) {
				term.c.attr.bg = attr[i] - 40;
			} else if (BETWEEN(attr[i], 90, 97)) {
				term.c.attr.fg = attr[i] - 90 + 8;
			} else if (BETWEEN(attr[i], 100, 107)) {
				term.c.attr.bg = attr[i] - 100 + 8;
			} else {
				fprintf(stderr,
					"erresc(default): gfx attr %d unknown\n",
					attr[i]), csidump();
			}
			break;
		}
	}
}

void
tsetscroll(int t, int b)
{
	int temp;

	LIMIT(t, 0, term.row-1);
	LIMIT(b, 0, term.row-1);
	if (t > b) {
		temp = t;
		t = b;
		b = temp;
	}
	term.top = t;
	term.bot = b;
}

void
tsetmode(int priv, int set, int *args, int narg)
{
	int *lim, mode;
	int alt;

	for (lim = args + narg; args < lim; ++args) {
		if (priv) {
			switch (*args) {
			case 1: /* DECCKM -- Cursor key */
				MODBIT(term.mode, set, MODE_APPCURSOR);
				break;
			case 5: /* DECSCNM -- Reverse video */
				mode = term.mode;
				MODBIT(term.mode, set, MODE_REVERSE);
				if (mode != term.mode)
					redraw();
				break;
			case 6: /* DECOM -- Origin */
				MODBIT(term.c.state, set, CURSOR_ORIGIN);
				tmoveato(0, 0);
				break;
			case 7: /* DECAWM -- Auto wrap */
				MODBIT(term.mode, set, MODE_WRAP);
				break;
			case 0:  /* Error (IGNORED) */
			case 2:  /* DECANM -- ANSI/VT52 (IGNORED) */
			case 3:  /* DECCOLM -- Column  (IGNORED) */
			case 4:  /* DECSCLM -- Scroll (IGNORED) */
			case 8:  /* DECARM -- Auto repeat (IGNORED) */
			case 18: /* DECPFF -- Printer feed (IGNORED) */
			case 19: /* DECPEX -- Printer extent (IGNORED) */
			case 42: /* DECNRCM -- National characters (IGNORED) */
			case 12: /* att610 -- Start blinking cursor (IGNORED) */
				break;
			case 25: /* DECTCEM -- Text Cursor Enable Mode */
				MODBIT(term.mode, !set, MODE_HIDE);
				break;
			case 9:    /* X10 mouse compatibility mode */
				xsetpointermotion(0);
				MODBIT(term.mode, 0, MODE_MOUSE);
				MODBIT(term.mode, set, MODE_MOUSEX10);
				break;
			case 1000: /* 1000: report button press */
				xsetpointermotion(0);
				MODBIT(term.mode, 0, MODE_MOUSE);
				MODBIT(term.mode, set, MODE_MOUSEBTN);
				break;
			case 1002: /* 1002: report motion on button press */
				xsetpointermotion(0);
				MODBIT(term.mode, 0, MODE_MOUSE);
				MODBIT(term.mode, set, MODE_MOUSEMOTION);
				break;
			case 1003: /* 1003: enable all mouse motions */
				xsetpointermotion(set);
				MODBIT(term.mode, 0, MODE_MOUSE);
				MODBIT(term.mode, set, MODE_MOUSEMANY);
				break;
			case 1004: /* 1004: send focus events to tty */
				MODBIT(term.mode, set, MODE_FOCUS);
				break;
			case 1006: /* 1006: extended reporting mode */
				MODBIT(term.mode, set, MODE_MOUSESGR);
				break;
			case 1034:
				MODBIT(term.mode, set, MODE_8BIT);
				break;
			case 1049: /* swap screen & set/restore cursor as xterm */
				if (!allowaltscreen)
					break;
				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
				/* FALLTHROUGH */
			case 47: /* swap screen */
			case 1047:
				if (!allowaltscreen)
					break;
				alt = IS_SET(MODE_ALTSCREEN);
				if (alt) {
					tclearregion(0, 0, term.col-1,
							term.row-1);
				}
				if (set ^ alt) /* set is always 1 or 0 */
					tswapscreen();
				if (*args != 1049)
					break;
				/* FALLTHROUGH */
			case 1048:
				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
				break;
			case 2004: /* 2004: bracketed paste mode */
				MODBIT(term.mode, set, MODE_BRCKTPASTE);
				break;
			/* Not implemented mouse modes. See comments there. */
			case 1001: /* mouse highlight mode; can hang the
				      terminal by design when implemented. */
			case 1005: /* UTF-8 mouse mode; will confuse
				      applications not supporting UTF-8
				      and luit. */
			case 1015: /* urxvt mangled mouse mode; incompatible
				      and can be mistaken for other control
				      codes. */
			default:
				fprintf(stderr,
					"erresc: unknown private set/reset mode %d\n",
					*args);
				break;
			}
		} else {
			switch (*args) {
			case 0:  /* Error (IGNORED) */
				break;
			case 2:  /* KAM -- keyboard action */
				MODBIT(term.mode, set, MODE_KBDLOCK);
				break;
			case 4:  /* IRM -- Insertion-replacement */
				MODBIT(term.mode, set, MODE_INSERT);
				break;
			case 12: /* SRM -- Send/Receive */
				MODBIT(term.mode, !set, MODE_ECHO);
				break;
			case 20: /* LNM -- Linefeed/new line */
				MODBIT(term.mode, set, MODE_CRLF);
				break;
			default:
				fprintf(stderr,
					"erresc: unknown set/reset mode %d\n",
					*args);
				break;
			}
		}
	}
}

void
csihandle(void)
{
	char buf[40];
	int len;

	switch (csiescseq.mode[0]) {
	default:
	unknown:
		fprintf(stderr, "erresc: unknown csi ");
		csidump();
		/* die(""); */
		break;
	case '@': /* ICH -- Insert <n> blank char */
		DEFAULT(csiescseq.arg[0], 1);
		tinsertblank(csiescseq.arg[0]);
		break;
	case 'A': /* CUU -- Cursor <n> Up */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(term.c.x, term.c.y-csiescseq.arg[0]);
		break;
	case 'B': /* CUD -- Cursor <n> Down */
	case 'e': /* VPR --Cursor <n> Down */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(term.c.x, term.c.y+csiescseq.arg[0]);
		break;
	case 'i': /* MC -- Media Copy */
		switch (csiescseq.arg[0]) {
		case 0:
			tdump();
			break;
		case 1:
			tdumpline(term.c.y);
			break;
		case 2: