text: /* See LICENSE for license details. */
  #include <ctype.h>
  #include <errno.h>
  #include <fcntl.h>
  #include <limits.h>
  #include <pwd.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <signal.h>
  #include <sys/ioctl.h>
  #include <sys/select.h>
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <termios.h>
  #include <unistd.h>
  #include <wchar.h>
  
  #include "st.h"
  #include "win.h"
  
  #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
  
  /* 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
  
  /* macros */
  #define IS_SET(flag)		((term.mode & (flag)) != 0)
  #define NUMMAXLEN(x)		((int)(sizeof(x) * 2.56 + 0.5) + 1)
  #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)
  
  /* constants */
  #define ISO14755CMD		"dmenu -w \"$WINDOWID\" -p codepoint: </dev/null"
  
  enum term_mode {
  	MODE_WRAP        = 1 << 0,
  	MODE_INSERT      = 1 << 1,
  	MODE_ALTSCREEN   = 1 << 2,
  	MODE_CRLF        = 1 << 3,
  	MODE_ECHO        = 1 << 4,
  	MODE_PRINT       = 1 << 5,
  	MODE_UTF8        = 1 << 6,
  	MODE_SIXEL       = 1 << 7,
  };
  
  enum cursor_movement {
  	CURSOR_SAVE,
  	CURSOR_LOAD
  };
  
  enum cursor_state {
  	CURSOR_DEFAULT  = 0,
  	CURSOR_WRAPNEXT = 1,
  	CURSOR_ORIGIN   = 2
  };
  
  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,
  };
  
  typedef struct {
  	Glyph attr; /* current char attributes */
  	int x;
  	int y;
  	char state;
  } TCursor;
  
  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;
  
  	int alt;
  } Selection;
  
  /* Internal representation of the screen */
  typedef struct {
  	int row;      /* nb row */
  	int col;      /* nb col */
  	Line *line;   /* screen */
  	Line *alt;    /* alternate screen */
  	int *dirty;   /* dirtyness of lines */
  	TCursor c;    /* cursor */
  	int ocx;      /* old cursor col */
  	int ocy;      /* old cursor row */
  	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 *tabs;
  } Term;
  
  /* 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;
  
  static void execsh(char *, char **);
  static void stty(char **);
  static void sigchld(int);
  static void ttywriteraw(const char *, size_t);
  
  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 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 tnewline(int);
  static void tputtab(int);
  static void tputc(Rune);
  static void treset(void);
  static void tscrollup(int, int);
  static void tscrolldown(int, int);
  static void tsetattr(int *, int);
  static void tsetchar(Rune, Glyph *, int, int);
  static void tsetdirt(int, int);
  static void tsetscroll(int, int);
  static void tswapscreen(void);
  static void tsetmode(int, int, int *, int);
  static int twrite(const char *, int, int);
  static void tfulldirt(void);
  static void tcontrolcode(uchar );
  static void tdectest(char );
  static void tdefutf8(char);
  static int32_t tdefcolor(int *, int *, int);
  static void tdeftran(char);
  static void tstrsequence(uchar);
  
  static void drawregion(int, int, int, int);
  
  static void selnormalize(void);
  static void selscroll(int, int);
  static void selsnap(int *, int *, int);
  
  static size_t utf8decode(const char *, Rune *, size_t);
  static Rune utf8decodebyte(char, size_t *);
  static char utf8encodebyte(Rune, size_t);
  static char *utf8strchr(char *, Rune);
  static size_t utf8validate(Rune *, size_t);
  
  static char *base64dec(const char *);
  static char base64dec_getc(const char **);
  
  static ssize_t xwrite(int, const char *, size_t);
  
  /* Globals */
  static Term term;
  static Selection sel;
  static CSIEscape csiescseq;
  static STREscape strescseq;
  static int iofd = 1;
  static int cmdfd;
  static pid_t pid;
  
  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};
  
  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;
  
  	if (!(p = malloc(len)))
  		die("malloc: %s\n", strerror(errno));
  
  	return p;
  }
  
  void *
  xrealloc(void *p, size_t len)
  {
  	if ((p = realloc(p, len)) == NULL)
  		die("realloc: %s\n", strerror(errno));
  
  	return p;
  }
  
  char *
  xstrdup(char *s)
  {
  	if ((s = strdup(s)) == NULL)
  		die("strdup: %s\n", strerror(errno));
  
  	return s;
  }
  
  size_t
  utf8decode(const 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;
  }
  
  static const char base64_digits[] = {
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 0, 0,
  	63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0, -1, 0, 0, 0, 0, 1,
  	2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
  	22, 23, 24, 25, 0, 0, 0, 0, 0, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34,
  	35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  };
  
  char
  base64dec_getc(const char **src)
  {
  	while (**src && !isprint(**src)) (*src)++;
  	return *((*src)++);
  }
  
  char *
  base64dec(const char *src)
  {
  	size_t in_len = strlen(src);
  	char *result, *dst;
  
  	if (in_len % 4)
  		in_len += 4 - (in_len % 4);
  	result = dst = xmalloc(in_len / 4 * 3 + 1);
  	while (*src) {
  		int a = base64_digits[(unsigned char) base64dec_getc(&src)];
  		int b = base64_digits[(unsigned char) base64dec_getc(&src)];
  		int c = base64_digits[(unsigned char) base64dec_getc(&src)];
  		int d = base64_digits[(unsigned char) base64dec_getc(&src)];
  
  		*dst++ = (a << 2) | ((b & 0x30) >> 4);
  		if (c == -1)
  			break;
  		*dst++ = ((b & 0x0f) << 4) | ((c & 0x3c) >> 2);
  		if (d == -1)
  			break;
  		*dst++ = ((c & 0x03) << 6) | d;
  	}
  	*dst = '\0';
  	return result;
  }
  
  void
  selinit(void)
  {
  	sel.mode = SEL_IDLE;
  	sel.snap = 0;
  	sel.ob.x = -1;
  }
  
  int
  tlinelen(int y)
  {
  	int i = term.col;
  
  	if (term.line[y][i - 1].mode & ATTR_WRAP)
  		return i;
  
  	while (i > 0 && term.line[y][i - 1].u == ' ')
  		--i;
  
  	return i;
  }
  
  void
  selstart(int col, int row, int snap)
  {
  	selclear();
  	sel.mode = SEL_EMPTY;
  	sel.type = SEL_REGULAR;
  	sel.alt = IS_SET(MODE_ALTSCREEN);
  	sel.snap = snap;
  	sel.oe.x = sel.ob.x = col;
  	sel.oe.y = sel.ob.y = row;
  	selnormalize();
  
  	if (sel.snap != 0)
  		sel.mode = SEL_READY;
  	tsetdirt(sel.nb.y, sel.ne.y);
  }
  
  void
  selextend(int col, int row, int type, int done)
  {
  	int oldey, oldex, oldsby, oldsey, oldtype;
  
  	if (sel.mode == SEL_IDLE)
  		return;
  	if (done && sel.mode == SEL_EMPTY) {
  		selclear();
  		return;
  	}
  
  	oldey = sel.oe.y;
  	oldex = sel.oe.x;
  	oldsby = sel.nb.y;
  	oldsey = sel.ne.y;
  	oldtype = sel.type;
  
  	sel.oe.x = col;
  	sel.oe.y = row;
  	selnormalize();
  	sel.type = type;
  
  	if (oldey != sel.oe.y || oldex != sel.oe.x || oldtype != sel.type)
  		tsetdirt(MIN(sel.nb.y, oldsby), MAX(sel.ne.y, oldsey));
  
  	sel.mode = done ? SEL_IDLE : SEL_READY;
  }
  
  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 || sel.ob.x == -1 ||
  			sel.alt != IS_SET(MODE_ALTSCREEN))
  		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 = &term.line[*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 (!(term.line[yt][xt].mode & ATTR_WRAP))
  					break;
  			}
  
  			if (newx >= tlinelen(newy))
  				break;
  
  			gp = &term.line[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 (!(term.line[*y-1][term.col-1].mode
  						& ATTR_WRAP)) {
  					break;
  				}
  			}
  		} else if (direction > 0) {
  			for (; *y < term.row-1; *y += direction) {
  				if (!(term.line[*y][term.col-1].mode
  						& ATTR_WRAP)) {
  					break;
  				}
  			}
  		}
  		break;
  	}
  }
  
  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 = &term.line[y][sel.nb.x];
  			lastx = sel.ne.x;
  		} else {
  			gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
  			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
  		}
  		last = &term.line[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
  selclear(void)
  {
  	if (sel.ob.x == -1)
  		return;
  	sel.mode = SEL_IDLE;
  	sel.ob.x = -1;
  	tsetdirt(sel.nb.y, sel.ne.y);
  }
  
  void
  die(const char *errstr, ...)
  {
  	va_list ap;
  
  	va_start(ap, errstr);
  	vfprintf(stderr, errstr, ap);
  	va_end(ap);
  	exit(1);
  }
  
  void
  execsh(char *cmd, char **args)
  {
  	char *sh, *prog;
  	const struct passwd *pw;
  
  	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 : cmd;
  
  	if (args)
  		prog = args[0];
  	else if (utmp)
  		prog = utmp;
  	else
  		prog = sh;
  	DEFAULT(args, ((char *[]) {prog, NULL}));
  
  	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);
  
  	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(char **args)
  {
  	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 = args; 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");
  }
  
  int
  ttynew(char *line, char *cmd, char *out, char **args)
  {
  	int m, s;
  
  	if (out) {
  		term.mode |= MODE_PRINT;
  		iofd = (!strcmp(out, "-")) ?
  			  1 : open(out, O_WRONLY | O_CREAT, 0666);
  		if (iofd < 0) {
  			fprintf(stderr, "Error opening %s:%s\n",
  				out, strerror(errno));
  		}
  	}
  
  	if (line) {
  		if ((cmdfd = open(line, O_RDWR)) < 0)
  			die("open line '%s' failed: %s\n",
  			    line, strerror(errno));
  		dup2(cmdfd, 0);
  		stty(args);
  		return cmdfd;
  	}
  
  	/* seems to work fine on linux, openbsd and freebsd */
  	if (openpty(&m, &s, NULL, NULL, NULL) < 0)
  		die("openpty failed: %s\n", strerror(errno));
  
  	switch (pid = fork()) {
  	case -1:
  		die("fork failed: %s\n", strerror(errno));
  		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(cmd, args);
  		break;
  	default:
  		close(s);
  		cmdfd = m;
  		signal(SIGCHLD, sigchld);
  		break;
  	}
  	return cmdfd;
  }
  
  size_t
  ttyread(void)
  {
  	static char buf[BUFSIZ];
  	static int buflen = 0;
  	int written;
  	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;
  
  	written = twrite(buf, buflen, 0);
  	buflen -= written;
  	/* keep any uncomplete utf8 char for the next call */
  	if (buflen > 0)
  		memmove(buf, buf + written, buflen);
  
  	return ret;
  }
  
  void
  ttywrite(const char *s, size_t n, int may_echo)
  {
  	const char *next;
  
  	if (may_echo && IS_SET(MODE_ECHO))
  		twrite(s, n, 1);
  
  	if (!IS_SET(MODE_CRLF)) {
  		ttywriteraw(s, n);
  		return;
  	}
  
  	/* This is similar to how the kernel handles ONLCR for ttys */
  	while (n > 0) {
  		if (*s == '\r') {
  			next = s + 1;
  			ttywriteraw("\r\n", 2);
  		} else {
  			next = memchr(s, '\r', n);
  			DEFAULT(next, s + n);
  			ttywriteraw(s, next - s);
  		}
  		n -= next - s;
  		s = next;
  	}
  }
  
  void
  ttywriteraw(const char *s, size_t n)
  {
  	fd_set wfd, rfd;
  	ssize_t r;
  	size_t lim = 256;
  
  	/*
  	 * 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
  ttyresize(int tw, int th)
  {
  	struct winsize w;
  
  	w.ws_row = term.row;
  	w.ws_col = term.col;
  	w.ws_xpixel = tw;
  	w.ws_ypixel = th;
  	if (ioctl(cmdfd, TIOCSWINSZ, &w) < 0)
  		fprintf(stderr, "Couldn't set window size: %s\n", strerror(errno));
  }
  
  void
  ttyhangup()
  {
  	/* Send SIGHUP to shell */
  	kill(pid, SIGHUP);
  }
  
  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);
  	treset();
  }
  
  void
  tswapscreen(void)
  {
  	Line *tmp = term.line;
  
  	term.line = term.alt;
  	term.alt = tmp;
  	term.mode ^= MODE_ALTSCREEN;
  	tfulldirt();
  }
  
  void
  tscrolldown(int orig, int n)
  {
  	int i;
  	Line temp;
  
  	LIMIT(n, 0, term.bot-orig+1);
  
  	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 i;
  	Line temp;
  
  	LIMIT(n, 0, term.bot-orig+1);
  
  	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();
  			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);
  	} 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();
  			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);
  }
  
  void
  tdeleteline(int n)
  {
  	if (BETWEEN(term.c.y, term.top, term.bot))
  		tscrollup(term.c.y, n);
  }
  
  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 alt, *lim;
  
  	for (lim = args + narg; args < lim; ++args) {
  		if (priv) {
  			switch (*args) {
  			case 1: /* DECCKM -- Cursor key */
  				xsetmode(set, MODE_APPCURSOR);
  				break;
  			case 5: /* DECSCNM -- Reverse video */
  				xsetmode(set, MODE_REVERSE);
  				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 */
  				xsetmode(!set, MODE_HIDE);
  				break;
  			case 9:    /* X10 mouse compatibility mode */
  				xsetpointermotion(0);
  				xsetmode(0, MODE_MOUSE);
  				xsetmode(set, MODE_MOUSEX10);
  				break;
  			case 1000: /* 1000: report button press */
  				xsetpointermotion(0);
  				xsetmode(0, MODE_MOUSE);
  				xsetmode(set, MODE_MOUSEBTN);
  				break;
  			case 1002: /* 1002: report motion on button press */
  				xsetpointermotion(0);
  				xsetmode(0, MODE_MOUSE);
  				xsetmode(set, MODE_MOUSEMOTION);
  				break;
  			case 1003: /* 1003: enable all mouse motions */
  				xsetpointermotion(set);
  				xsetmode(0, MODE_MOUSE);
  				xsetmode(set, MODE_MOUSEMANY);
  				break;
  			case 1004: /* 1004: send focus events to tty */
  				xsetmode(set, MODE_FOCUS);
  				break;
  			case 1006: /* 1006: extended reporting mode */
  				xsetmode(set, MODE_MOUSESGR);
  				break;
  			case 1034:
  				xsetmode(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 */
  				xsetmode(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:
  				xsetmode(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:
  			tdumpsel();
  			break;
  		case 4:
  			term.mode &= ~MODE_PRINT;
  			break;
  		case 5:
  			term.mode |= MODE_PRINT;
  			break;
  		}
  		break;
  	case 'c': /* DA -- Device Attributes */
  		if (csiescseq.arg[0] == 0)
  			ttywrite(vtiden, strlen(vtiden), 0);
  		break;
  	case 'C': /* CUF -- Cursor <n> Forward */
  	case 'a': /* HPR -- Cursor <n> Forward */
  		DEFAULT(csiescseq.arg[0], 1);
  		tmoveto(term.c.x+csiescseq.arg[0], term.c.y);
  		break;
  	case 'D': /* CUB -- Cursor <n> Backward */
  		DEFAULT(csiescseq.arg[0], 1);
  		tmoveto(term.c.x-csiescseq.arg[0], term.c.y);
  		break;
  	case 'E': /* CNL -- Cursor <n> Down and first col */
  		DEFAULT(csiescseq.arg[0], 1);
  		tmoveto(0, term.c.y+csiescseq.arg[0]);
  		break;
  	case 'F': /* CPL -- Cursor <n> Up and first col */
  		DEFAULT(csiescseq.arg[0], 1);
  		tmoveto(0, term.c.y-csiescseq.arg[0]);
  		break;
  	case 'g': /* TBC -- Tabulation clear */
  		switch (csiescseq.arg[0]) {
  		case 0: /* clear current tab stop */
  			term.tabs[term.c.x] = 0;
  			break;
  		case 3: /* clear all the tabs */
  			memset(term.tabs, 0, term.col * sizeof(*term.tabs));
  			break;
  		default:
  			goto unknown;
  		}
  		break;
  	case 'G': /* CHA -- Move to <col> */
  	case '`': /* HPA */
  		DEFAULT(csiescseq.arg[0], 1);
  		tmoveto(csiescseq.arg[0]-1, term.c.y);
  		break;
  	case 'H': /* CUP -- Move to <row> <col> */
  	case 'f': /* HVP */
  		DEFAULT(csiescseq.arg[0], 1);
  		DEFAULT(csiescseq.arg[1], 1);
  		tmoveato(csiescseq.arg[1]-1, csiescseq.arg[0]-1);
  		break;
  	case 'I': /* CHT -- Cursor Forward Tabulation <n> tab stops */
  		DEFAULT(csiescseq.arg[0], 1);
  		tputtab(csiescseq.arg[0]);
  		break;
  	case 'J': /* ED -- Clear screen */
  		switch (csiescseq.arg[0]) {
  		case 0: /* below */
  			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
  			if (term.c.y < term.row-1) {
  				tclearregion(0, term.c.y+1, term.col-1,
  						term.row-1);
  			}
  			break;
  		case 1: /* above */
  			if (term.c.y > 1)
  				tclearregion(0, 0, term.col-1, term.c.y-1);
  			tclearregion(0, term.c.y, term.c.x, term.c.y);
  			break;
  		case 2: /* all */
  			tclearregion(0, 0, term.col-1, term.row-1);
  			break;
  		default:
  			goto unknown;
  		}
  		break;
  	case 'K': /* EL -- Clear line */
  		switch (csiescseq.arg[0]) {
  		case 0: /* right */
  			tclearregion(term.c.x, term.c.y, term.col-1,
  					term.c.y);
  			break;
  		case 1: /* left */
  			tclearregion(0, term.c.y, term.c.x, term.c.y);
  			break;
  		case 2: /* all */
  			tclearregion(0, term.c.y, term.col-1, term.c.y);
  			break;
  		}
  		break;
  	case 'S': /* SU -- Scroll <n> line up */
  		DEFAULT(csiescseq.arg[0], 1);
  		tscrollup(term.top, csiescseq.arg[0]);
  		break;
  	case 'T': /* SD -- Scroll <n> line down */
  		DEFAULT(csiescseq.arg[0], 1);
  		tscrolldown(term.top, csiescseq.arg[0]);
  		break;
  	case 'L': /* IL -- Insert <n> blank lines */
  		DEFAULT(csiescseq.arg[0], 1);
  		tinsertblankline(csiescseq.arg[0]);
  		break;
  	case 'l': /* RM -- Reset Mode */
  		tsetmode(csiescseq.priv, 0, csiescseq.arg, csiescseq.narg);
  		break;
  	case 'M': /* DL -- Delete <n> lines */
  		DEFAULT(csiescseq.arg[0], 1);
  		tdeleteline(csiescseq.arg[0]);
  		break;
  	case 'X': /* ECH -- Erase <n> char */
  		DEFAULT(csiescseq.arg[0], 1);
  		tclearregion(term.c.x, term.c.y,
  				term.c.x + csiescseq.arg[0] - 1, term.c.y);
  		break;
  	case 'P': /* DCH -- Delete <n> char */
  		DEFAULT(csiescseq.arg[0], 1);
  		tdeletechar(csiescseq.arg[0]);
  		break;
  	case 'Z': /* CBT -- Cursor Backward Tabulation <n> tab stops */
  		DEFAULT(csiescseq.arg[0], 1);
  		tputtab(-csiescseq.arg[0]);
  		break;
  	case 'd': /* VPA -- Move to <row> */
  		DEFAULT(csiescseq.arg[0], 1);
  		tmoveato(term.c.x, csiescseq.arg[0]-1);
  		break;
  	case 'h': /* SM -- Set terminal mode */
  		tsetmode(csiescseq.priv, 1, csiescseq.arg, csiescseq.narg);
  		break;
  	case 'm': /* SGR -- Terminal attribute (color) */
  		tsetattr(csiescseq.arg, csiescseq.narg);
  		break;
  	case 'n': /* DSR – Device Status Report (cursor position) */
  		if (csiescseq.arg[0] == 6) {
  			len = snprintf(buf, sizeof(buf),"\033[%i;%iR",
  					term.c.y+1, term.c.x+1);
  			ttywrite(buf, len, 0);
  		}
  		break;
  	case 'r': /* DECSTBM -- Set Scrolling Region */
  		if (csiescseq.priv) {
  			goto unknown;
  		} else {
  			DEFAULT(csiescseq.arg[0], 1);
  			DEFAULT(csiescseq.arg[1], term.row);
  			tsetscroll(csiescseq.arg[0]-1, csiescseq.arg[1]-1);
  			tmoveato(0, 0);
  		}
  		break;
  	case 's': /* DECSC -- Save cursor position (ANSI.SYS) */
  		tcursor(CURSOR_SAVE);
  		break;
  	case 'u': /* DECRC -- Restore cursor position (ANSI.SYS) */
  		tcursor(CURSOR_LOAD);
  		break;
  	case ' ':
  		switch (csiescseq.mode[1]) {
  		case 'q': /* DECSCUSR -- Set Cursor Style */
  			if (xsetcursor(csiescseq.arg[0]))
  				goto unknown;
  			break;
  		default:
  			goto unknown;
  		}
  		break;
  	}
  }
  
  void
  csidump(void)
  {
  	int i;
  	uint c;
  
  	fprintf(stderr, "ESC[");
  	for (i = 0; i < csiescseq.len; i++) {
  		c = csiescseq.buf[i] & 0xff;
  		if (isprint(c)) {
  			putc(c, stderr);
  		} else if (c == '\n') {
  			fprintf(stderr, "(\\n)");
  		} else if (c == '\r') {
  			fprintf(stderr, "(\\r)");
  		} else if (c == 0x1b) {
  			fprintf(stderr, "(\\e)");
  		} else {
  			fprintf(stderr, "(%02x)", c);
  		}
  	}
  	putc('\n', stderr);
  }
  
  void
  csireset(void)
  {
  	memset(&csiescseq, 0, sizeof(csiescseq));
  }
  
  void
  strhandle(void)
  {
  	char *p = NULL;
  	int j, narg, par;
  
  	term.esc &= ~(ESC_STR_END|ESC_STR);
  	strparse();
  	par = (narg = strescseq.narg) ? atoi(strescseq.args[0]) : 0;
  
  	switch (strescseq.type) {
  	case ']': /* OSC -- Operating System Command */
  		switch (par) {
  		case 0:
  		case 1:
  		case 2:
  			if (narg > 1)
  				xsettitle(strescseq.args[1]);
  			return;
  		case 52:
  			if (narg > 2) {
  				char *dec;
  
  				dec = base64dec(strescseq.args[2]);
  				if (dec) {
  					xsetsel(dec);
  					xclipcopy();
  				} else {
  					fprintf(stderr, "erresc: invalid base64\n");
  				}
  			}
  			return;
  		case 4: /* color set */
  			if (narg < 3)
  				break;
  			p = strescseq.args[2];
  			/* FALLTHROUGH */
  		case 104: /* color reset, here p = NULL */
  			j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
  			if (xsetcolorname(j, p)) {
  				fprintf(stderr, "erresc: invalid color %s\n", p);
  			} else {
  				/*
  				 * TODO if defaultbg color is changed, borders
  				 * are dirty
  				 */
  				redraw();
  			}
  			return;
  		}
  		break;
  	case 'k': /* old title set compatibility */
  		xsettitle(strescseq.args[0]);
  		return;
  	case 'P': /* DCS -- Device Control String */
  		term.mode |= ESC_DCS;
  	case '_': /* APC -- Application Program Command */
  	case '^': /* PM -- Privacy Message */
  		return;
  	}
  
  	fprintf(stderr, "erresc: unknown str ");
  	strdump();
  }
  
  void
  strparse(void)
  {
  	int c;
  	char *p = strescseq.buf;
  
  	strescseq.narg = 0;
  	strescseq.buf[strescseq.len] = '\0';
  
  	if (*p == '\0')
  		return;
  
  	while (strescseq.narg < STR_ARG_SIZ) {
  		strescseq.args[strescseq.narg++] = p;
  		while ((c = *p) != ';' && c != '\0')
  			++p;
  		if (c == '\0')
  			return;
  		*p++ = '\0';
  	}
  }
  
  void
  strdump(void)
  {
  	int i;
  	uint c;
  
  	fprintf(stderr, "ESC%c", strescseq.type);
  	for (i = 0; i < strescseq.len; i++) {
  		c = strescseq.buf[i] & 0xff;
  		if (c == '\0') {
  			putc('\n', stderr);
  			return;
  		} else if (isprint(c)) {
  			putc(c, stderr);
  		} else if (c == '\n') {
  			fprintf(stderr, "(\\n)");
  		} else if (c == '\r') {
  			fprintf(stderr, "(\\r)");
  		} else if (c == 0x1b) {
  			fprintf(stderr, "(\\e)");
  		} else {
  			fprintf(stderr, "(%02x)", c);
  		}
  	}
  	fprintf(stderr, "ESC\\\n");
  }
  
  void
  strreset(void)
  {
  	memset(&strescseq, 0, sizeof(strescseq));
  }
  
  void
  sendbreak(const Arg *arg)
  {
  	if (tcsendbreak(cmdfd, 0))
  		perror("Error sending break");
  }
  
  void
  tprinter(char *s, size_t len)
  {
  	if (iofd != -1 && xwrite(iofd, s, len) < 0) {
  		perror("Error writing to output file");
  		close(iofd);
  		iofd = -1;
  	}
  }
  
  void
  iso14755(const Arg *arg)
  {
  	FILE *p;
  	char *us, *e, codepoint[9], uc[UTF_SIZ];
  	unsigned long utf32;
  
  	if (!(p = popen(ISO14755CMD, "r")))
  		return;
  
  	us = fgets(codepoint, sizeof(codepoint), p);
  	pclose(p);
  
  	if (!us || *us == '\0' || *us == '-' || strlen(us) > 7)
  		return;
  	if ((utf32 = strtoul(us, &e, 16)) == ULONG_MAX ||
  	    (*e != '\n' && *e != '\0'))
  		return;
  
  	ttywrite(uc, utf8encode(utf32, uc), 1);
  }
  
  void
  toggleprinter(const Arg *arg)
  {
  	term.mode ^= MODE_PRINT;
  }
  
  void
  printscreen(const Arg *arg)
  {
  	tdump();
  }
  
  void
  printsel(const Arg *arg)
  {
  	tdumpsel();
  }
  
  void
  tdumpsel(void)
  {
  	char *ptr;
  
  	if ((ptr = getsel())) {
  		tprinter(ptr, strlen(ptr));
  		free(ptr);
  	}
  }
  
  void
  tdumpline(int n)
  {
  	char buf[UTF_SIZ];
  	Glyph *bp, *end;
  
  	bp = &term.line[n][0];
  	end = &bp[MIN(tlinelen(n), term.col) - 1];
  	if (bp != end || bp->u != ' ') {
  		for ( ;bp <= end; ++bp)
  			tprinter(buf, utf8encode(bp->u, buf));
  	}
  	tprinter("\n", 1);
  }
  
  void
  tdump(void)
  {
  	int i;
  
  	for (i = 0; i < term.row; ++i)
  		tdumpline(i);
  }
  
  void
  tputtab(int n)
  {
  	uint x = term.c.x;
  
  	if (n > 0) {
  		while (x < term.col && n--)
  			for (++x; x < term.col && !term.tabs[x]; ++x)
  				/* nothing */ ;
  	} else if (n < 0) {
  		while (x > 0 && n++)
  			for (--x; x > 0 && !term.tabs[x]; --x)
  				/* nothing */ ;
  	}
  	term.c.x = LIMIT(x, 0, term.col-1);
  }
  
  void
  tdefutf8(char ascii)
  {
  	if (ascii == 'G')
  		term.mode |= MODE_UTF8;
  	else if (ascii == '@')
  		term.mode &= ~MODE_UTF8;
  }
  
  void
  tdeftran(char ascii)
  {
  	static char cs[] = "0B";
  	static int vcs[] = {CS_GRAPHIC0, CS_USA};
  	char *p;
  
  	if ((p = strchr(cs, ascii)) == NULL) {
  		fprintf(stderr, "esc unhandled charset: ESC ( %c\n", ascii);
  	} else {
  		term.trantbl[term.icharset] = vcs[p - cs];
  	}
  }
  
  void
  tdectest(char c)
  {
  	int x, y;
  
  	if (c == '8') { /* DEC screen alignment test. */
  		for (x = 0; x < term.col; ++x) {
  			for (y = 0; y < term.row; ++y)
  				tsetchar('E', &term.c.attr, x, y);
  		}
  	}
  }
  
  void
  tstrsequence(uchar c)
  {
  	strreset();
  
  	switch (c) {
  	case 0x90:   /* DCS -- Device Control String */
  		c = 'P';
  		term.esc |= ESC_DCS;
  		break;
  	case 0x9f:   /* APC -- Application Program Command */
  		c = '_';
  		break;
  	case 0x9e:   /* PM -- Privacy Message */
  		c = '^';
  		break;
  	case 0x9d:   /* OSC -- Operating System Command */
  		c = ']';
  		break;
  	}
  	strescseq.type = c;
  	term.esc |= ESC_STR;
  }
  
  void
  tcontrolcode(uchar ascii)
  {
  	switch (ascii) {
  	case '\t':   /* HT */
  		tputtab(1);
  		return;
  	case '\b':   /* BS */
  		tmoveto(term.c.x-1, term.c.y);
  		return;
  	case '\r':   /* CR */
  		tmoveto(0, term.c.y);
  		return;
  	case '\f':   /* LF */
  	case '\v':   /* VT */
  	case '\n':   /* LF */
  		/* go to first col if the mode is set */
  		tnewline(IS_SET(MODE_CRLF));
  		return;
  	case '\a':   /* BEL */
  		if (term.esc & ESC_STR_END) {
  			/* backwards compatibility to xterm */
  			strhandle();
  		} else {
  			xbell();
  		}
  		break;
  	case '\033': /* ESC */
  		csireset();
  		term.esc &= ~(ESC_CSI|ESC_ALTCHARSET|ESC_TEST);
  		term.esc |= ESC_START;
  		return;
  	case '\016': /* SO (LS1 -- Locking shift 1) */
  	case '\017': /* SI (LS0 -- Locking shift 0) */
  		term.charset = 1 - (ascii - '\016');
  		return;
  	case '\032': /* SUB */
  		tsetchar('?', &term.c.attr, term.c.x, term.c.y);
  	case '\030': /* CAN */
  		csireset();
  		break;
  	case '\005': /* ENQ (IGNORED) */
  	case '\000': /* NUL (IGNORED) */
  	case '\021': /* XON (IGNORED) */
  	case '\023': /* XOFF (IGNORED) */
  	case 0177:   /* DEL (IGNORED) */
  		return;
  	case 0x80:   /* TODO: PAD */
  	case 0x81:   /* TODO: HOP */
  	case 0x82:   /* TODO: BPH */
  	case 0x83:   /* TODO: NBH */
  	case 0x84:   /* TODO: IND */
  		break;
  	case 0x85:   /* NEL -- Next line */
  		tnewline(1); /* always go to first col */
  		break;
  	case 0x86:   /* TODO: SSA */
  	case 0x87:   /* TODO: ESA */
  		break;
  	case 0x88:   /* HTS -- Horizontal tab stop */
  		term.tabs[term.c.x] = 1;
  		break;
  	case 0x89:   /* TODO: HTJ */
  	case 0x8a:   /* TODO: VTS */
  	case 0x8b:   /* TODO: PLD */
  	case 0x8c:   /* TODO: PLU */
  	case 0x8d:   /* TODO: RI */
  	case 0x8e:   /* TODO: SS2 */
  	case 0x8f:   /* TODO: SS3 */
  	case 0x91:   /* TODO: PU1 */
  	case 0x92:   /* TODO: PU2 */
  	case 0x93:   /* TODO: STS */
  	case 0x94:   /* TODO: CCH */
  	case 0x95:   /* TODO: MW */
  	case 0x96:   /* TODO: SPA */
  	case 0x97:   /* TODO: EPA */
  	case 0x98:   /* TODO: SOS */
  	case 0x99:   /* TODO: SGCI */
  		break;
  	case 0x9a:   /* DECID -- Identify Terminal */
  		ttywrite(vtiden, strlen(vtiden), 0);
  		break;
  	case 0x9b:   /* TODO: CSI */
  	case 0x9c:   /* TODO: ST */
  		break;
  	case 0x90:   /* DCS -- Device Control String */
  	case 0x9d:   /* OSC -- Operating System Command */
  	case 0x9e:   /* PM -- Privacy Message */
  	case 0x9f:   /* APC -- Application Program Command */
  		tstrsequence(ascii);
  		return;
  	}
  	/* only CAN, SUB, \a and C1 chars interrupt a sequence */
  	term.esc &= ~(ESC_STR_END|ESC_STR);
  }
  
  /*
   * returns 1 when the sequence is finished and it hasn't to read
   * more characters for this sequence, otherwise 0
   */
  int
  eschandle(uchar ascii)
  {
  	switch (ascii) {
  	case '[':
  		term.esc |= ESC_CSI;
  		return 0;
  	case '#':
  		term.esc |= ESC_TEST;
  		return 0;
  	case '%':
  		term.esc |= ESC_UTF8;
  		return 0;
  	case 'P': /* DCS -- Device Control String */
  	case '_': /* APC -- Application Program Command */
  	case '^': /* PM -- Privacy Message */
  	case ']': /* OSC -- Operating System Command */
  	case 'k': /* old title set compatibility */
  		tstrsequence(ascii);
  		return 0;
  	case 'n': /* LS2 -- Locking shift 2 */
  	case 'o': /* LS3 -- Locking shift 3 */
  		term.charset = 2 + (ascii - 'n');
  		break;
  	case '(': /* GZD4 -- set primary charset G0 */
  	case ')': /* G1D4 -- set secondary charset G1 */
  	case '*': /* G2D4 -- set tertiary charset G2 */
  	case '+': /* G3D4 -- set quaternary charset G3 */
  		term.icharset = ascii - '(';
  		term.esc |= ESC_ALTCHARSET;
  		return 0;
  	case 'D': /* IND -- Linefeed */
  		if (term.c.y == term.bot) {
  			tscrollup(term.top, 1);
  		} else {
  			tmoveto(term.c.x, term.c.y+1);
  		}
  		break;
  	case 'E': /* NEL -- Next line */
  		tnewline(1); /* always go to first col */
  		break;
  	case 'H': /* HTS -- Horizontal tab stop */
  		term.tabs[term.c.x] = 1;
  		break;
  	case 'M': /* RI -- Reverse index */
  		if (term.c.y == term.top) {
  			tscrolldown(term.top, 1);
  		} else {
  			tmoveto(term.c.x, term.c.y-1);
  		}
  		break;
  	case 'Z': /* DECID -- Identify Terminal */
  		ttywrite(vtiden, strlen(vtiden), 0);
  		break;
  	case 'c': /* RIS -- Reset to inital state */
  		treset();
  		resettitle();
  		xloadcols();
  		break;
  	case '=': /* DECPAM -- Application keypad */
  		xsetmode(1, MODE_APPKEYPAD);
  		break;
  	case '>': /* DECPNM -- Normal keypad */
  		xsetmode(0, MODE_APPKEYPAD);
  		break;
  	case '7': /* DECSC -- Save Cursor */
  		tcursor(CURSOR_SAVE);
  		break;
  	case '8': /* DECRC -- Restore Cursor */
  		tcursor(CURSOR_LOAD);
  		break;
  	case '\\': /* ST -- String Terminator */
  		if (term.esc & ESC_STR_END)
  			strhandle();
  		break;
  	default:
  		fprintf(stderr, "erresc: unknown sequence ESC 0x%02X '%c'\n",
  			(uchar) ascii, isprint(ascii)? ascii:'.');
  		break;
  	}
  	return 1;
  }
  
  void
  tputc(Rune u)
  {
  	char c[UTF_SIZ];
  	int control;
  	int width, len;
  	Glyph *gp;
  
  	control = ISCONTROL(u);
  	if (!IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
  		c[0] = u;
  		width = len = 1;
  	} else {
  		len = utf8encode(u, c);
  		if (!control && (width = wcwidth(u)) == -1) {
  			memcpy(c, "\357\277\275", 4); /* UTF_INVALID */
  			width = 1;
  		}
  	}
  
  	if (IS_SET(MODE_PRINT))
  		tprinter(c, len);
  
  	/*
  	 * STR sequence must be checked before anything else
  	 * because it uses all following characters until it
  	 * receives a ESC, a SUB, a ST or any other C1 control
  	 * character.
  	 */
  	if (term.esc & ESC_STR) {
  		if (u == '\a' || u == 030 || u == 032 || u == 033 ||
  		   ISCONTROLC1(u)) {
  			term.esc &= ~(ESC_START|ESC_STR|ESC_DCS);
  			if (IS_SET(MODE_SIXEL)) {
  				/* TODO: render sixel */;
  				term.mode &= ~MODE_SIXEL;
  				return;
  			}
  			term.esc |= ESC_STR_END;
  			goto check_control_code;
  		}
  
  
  		if (IS_SET(MODE_SIXEL)) {
  			/* TODO: implement sixel mode */
  			return;
  		}
  		if (term.esc&ESC_DCS && strescseq.len == 0 && u == 'q')
  			term.mode |= MODE_SIXEL;
  
  		if (strescseq.len+len >= sizeof(strescseq.buf)-1) {
  			/*
  			 * Here is a bug in terminals. If the user never sends
  			 * some code to stop the str or esc command, then st
  			 * will stop responding. But this is better than
  			 * silently failing with unknown characters. At least
  			 * then users will report back.
  			 *
  			 * In the case users ever get fixed, here is the code:
  			 */
  			/*
  			 * term.esc = 0;
  			 * strhandle();
  			 */
  			return;
  		}
  
  		memmove(&strescseq.buf[strescseq.len], c, len);
  		strescseq.len += len;
  		return;
  	}
  
  check_control_code:
  	/*
  	 * Actions of control codes must be performed as soon they arrive
  	 * because they can be embedded inside a control sequence, and
  	 * they must not cause conflicts with sequences.
  	 */
  	if (control) {
  		tcontrolcode(u);
  		/*
  		 * control codes are not shown ever
  		 */
  		return;
  	} else if (term.esc & ESC_START) {
  		if (term.esc & ESC_CSI) {
  			csiescseq.buf[csiescseq.len++] = u;
  			if (BETWEEN(u, 0x40, 0x7E)
  					|| csiescseq.len >= \
  					sizeof(csiescseq.buf)-1) {
  				term.esc = 0;
  				csiparse();
  				csihandle();
  			}
  			return;
  		} else if (term.esc & ESC_UTF8) {
  			tdefutf8(u);
  		} else if (term.esc & ESC_ALTCHARSET) {
  			tdeftran(u);
  		} else if (term.esc & ESC_TEST) {
  			tdectest(u);
  		} else {
  			if (!eschandle(u))
  				return;
  			/* sequence already finished */
  		}
  		term.esc = 0;
  		/*
  		 * All characters which form part of a sequence are not
  		 * printed
  		 */
  		return;
  	}
  	if (sel.ob.x != -1 && BETWEEN(term.c.y, sel.ob.y, sel.oe.y))
  		selclear();
  
  	gp = &term.line[term.c.y][term.c.x];
  	if (IS_SET(MODE_WRAP) && (term.c.state & CURSOR_WRAPNEXT)) {
  		gp->mode |= ATTR_WRAP;
  		tnewline(1);
  		gp = &term.line[term.c.y][term.c.x];
  	}
  
  	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col)
  		memmove(gp+width, gp, (term.col - term.c.x - width) * sizeof(Glyph));
  
  	if (term.c.x+width > term.col) {
  		tnewline(1);
  		gp = &term.line[term.c.y][term.c.x];
  	}
  
  	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
  
  	if (width == 2) {
  		gp->mode |= ATTR_WIDE;
  		if (term.c.x+1 < term.col) {
  			gp[1].u = '\0';
  			gp[1].mode = ATTR_WDUMMY;
  		}
  	}
  	if (term.c.x+width < term.col) {
  		tmoveto(term.c.x+width, term.c.y);
  	} else {
  		term.c.state |= CURSOR_WRAPNEXT;
  	}
  }
  
  int
  twrite(const char *buf, int buflen, int show_ctrl)
  {
  	int charsize;
  	Rune u;
  	int n;
  
  	for (n = 0; n < buflen; n += charsize) {
  		if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
  			/* process a complete utf8 char */
  			charsize = utf8decode(buf + n, &u, buflen - n);
  			if (charsize == 0)
  				break;
  		} else {
  			u = buf[n] & 0xFF;
  			charsize = 1;
  		}
  		if (show_ctrl && ISCONTROL(u)) {
  			if (u & 0x80) {
  				u &= 0x7f;
  				tputc('^');
  				tputc('[');
  			} else if (u != '\n' && u != '\r' && u != '\t') {
  				u ^= 0x40;
  				tputc('^');
  			}
  		}
  		tputc(u);
  	}
  	return n;
  }
  
  void
  tresize(int col, int row)
  {
  	int i;
  	int minrow = MIN(row, term.row);
  	int mincol = MIN(col, term.col);
  	int *bp;
  	TCursor c;
  
  	if (col < 1 || row < 1) {
  		fprintf(stderr,
  		        "tresize: error resizing to %dx%d\n", col, row);
  		return;
  	}
  
  	/*
  	 * slide screen to keep cursor where we expect it -
  	 * tscrollup would work here, but we can optimize to
  	 * memmove because we're freeing the earlier lines
  	 */
  	for (i = 0; i <= term.c.y - row; i++) {
  		free(term.line[i]);
  		free(term.alt[i]);
  	}
  	/* ensure that both src and dst are not NULL */
  	if (i > 0) {
  		memmove(term.line, term.line + i, row * sizeof(Line));
  		memmove(term.alt, term.alt + i, row * sizeof(Line));
  	}
  	for (i += row; i < term.row; i++) {
  		free(term.line[i]);
  		free(term.alt[i]);
  	}
  
  	/* resize to new height */
  	term.line = xrealloc(term.line, row * sizeof(Line));
  	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
  	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
  	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
  
  	/* resize each row to new width, zero-pad if needed */
  	for (i = 0; i < minrow; i++) {
  		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
  		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
  	}
  
  	/* allocate any new rows */
  	for (/* i = minrow */; i < row; i++) {
  		term.line[i] = xmalloc(col * sizeof(Glyph));
  		term.alt[i] = xmalloc(col * sizeof(Glyph));
  	}
  	if (col > term.col) {
  		bp = term.tabs + term.col;
  
  		memset(bp, 0, sizeof(*term.tabs) * (col - term.col));
  		while (--bp > term.tabs && !*bp)
  			/* nothing */ ;
  		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
  			*bp = 1;
  	}
  	/* update terminal size */
  	term.col = col;
  	term.row = row;
  	/* reset scrolling region */
  	tsetscroll(0, row-1);
  	/* make use of the LIMIT in tmoveto */
  	tmoveto(term.c.x, term.c.y);
  	/* Clearing both screens (it makes dirty all lines) */
  	c = term.c;
  	for (i = 0; i < 2; i++) {
  		if (mincol < col && 0 < minrow) {
  			tclearregion(mincol, 0, col - 1, minrow - 1);
  		}
  		if (0 < col && minrow < row) {
  			tclearregion(0, minrow, col - 1, row - 1);
  		}
  		tswapscreen();
  		tcursor(CURSOR_LOAD);
  	}
  	term.c = c;
  }
  
  void
  resettitle(void)
  {
  	xsettitle(NULL);
  }
  
  void
  drawregion(int x1, int y1, int x2, int y2)
  {
  	int y;
  	for (y = y1; y < y2; y++) {
  		if (!term.dirty[y])
  			continue;
  
  		term.dirty[y] = 0;
  		xdrawline(term.line[y], x1, y, x2);
  	}
  }
  
  void
  draw(void)
  {
  	int cx = term.c.x;
  
  	if (!xstartdraw())
  		return;
  
  	/* adjust cursor position */
  	LIMIT(term.ocx, 0, term.col-1);
  	LIMIT(term.ocy, 0, term.row-1);
  	if (term.line[term.ocy][term.ocx].mode & ATTR_WDUMMY)
  		term.ocx--;
  	if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
  		cx--;
  
  	drawregion(0, 0, term.col, term.row);
  	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
  			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
  	term.ocx = cx, term.ocy = term.c.y;
  	xfinishdraw();
  }
  
  void
  redraw(void)
  {
  	tfulldirt();
  	draw();
  }
  