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
  #define HISTSIZE      2000
  
  /* 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)
  #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 -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 */
      Line hist[HISTSIZE]; /* history buffer */
      int histi;    /* history index */
      int scr;      /* scroll back */
      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, int);
  static void tscrolldown(int, 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 tsetcolor(int, int, int, uint32_t, uint32_t);
  static char * findlastany(char *, const char**, size_t);
  
  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 (TLINE(y)[i - 1].mode & ATTR_WRAP)
          return i;
  
      while (i > 0 && TLINE(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 = &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;
      }
  }
  
  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
  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 exited with status %d\n", WEXITSTATUS(stat));
      else if (WIFSIGNALED(stat))
          die("child terminated due to signal %d\n", WTERMSIG(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);
  #ifdef __OpenBSD__
          if (pledge("stdio getpw proc exec", NULL) == -1)
              die("pledge\n");
  #endif
          execsh(cmd, args);
          break;
      default:
  #ifdef __OpenBSD__
          if (pledge("stdio rpath tty proc", NULL) == -1)
              die("pledge\n");
  #endif
          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;
      Arg arg = (Arg) { .i = term.scr };
  
      kscrolldown(&arg);
  
      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
  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;
      }
  
      if (term.scr > 0 && term.scr < HISTSIZE)
          term.scr = MIN(term.scr + n, HISTSIZE-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, 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, 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 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], 0);
          break;
      case 'T': /* SD -- Scroll <n> line down */
          DEFAULT(csiescseq.arg[0], 1);
          tscrolldown(term.top, csiescseq.arg[0], 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
  externalpipe(const Arg *arg)
  {
      int to[2];
      char buf[UTF_SIZ];
      void (*oldsigpipe)(int);
      Glyph *bp, *end;
      int lastpos, n, newline;
  
      if (pipe(to) == -1)
          return;
  
      switch (fork()) {
      case -1:
          close(to[0]);
          close(to[1]);
          return;
      case 0:
          dup2(to[0], STDIN_FILENO);
          close(to[0]);
          close(to[1]);
          execvp(((char **)arg->v)[0], (char **)arg->v);
          fprintf(stderr, "st: execvp %s\n", ((char **)arg->v)[0]);
          perror("failed");
          exit(0);
      }
  
      close(to[0]);
      /* ignore sigpipe for now, in case child exists early */
      oldsigpipe = signal(SIGPIPE, SIG_IGN);
      newline = 0;
      for (n = 0; n < term.row; n++) {
          bp = term.line[n];
          lastpos = MIN(tlinelen(n) + 1, term.col) - 1;
          if (lastpos < 0)
              break;
          end = &bp[lastpos + 1];
          for (; bp < end; ++bp)
              if (xwrite(to[1], buf, utf8encode(bp->u, buf)) < 0)
                  break;
          if ((newline = term.line[n][lastpos].mode & ATTR_WRAP))
              continue;
          if (xwrite(to[1], "\n", 1) < 0)
              break;
          newline = 0;
      }
      if (newline)
          (void)xwrite(to[1], "\n", 1);
      close(to[1]);
      /* restore */
      signal(SIGPIPE, oldsigpipe);
  }
  
  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, 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, 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 initial 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, j;
      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));
  
      for (i = 0; i < HISTSIZE; i++) {
          term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
          for (j = mincol; j < col; j++) {
              term.hist[i][j] = term.c.attr;
              term.hist[i][j].u = ' ';
          }
      }
  
      /* 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(TLINE(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);
      if (term.scr == 0)
          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();
  }
  
  void
  tsetcolor( int row, int start, int end, uint32_t fg, uint32_t bg )
  {
      int i = start;
      for( ; i < end; ++i )
      {
          term.line[row][i].fg = fg;
          term.line[row][i].bg = bg;
      }
  }
  
  char *
  findlastany(char *str, const char** find, size_t len)
  {
      char* found = NULL;
      int i = 0;
      for(found = str + strlen(str) - 1; found >= str; --found) {
          for(i = 0; i < len; i++) {
              if(strncmp(found, find[i], strlen(find[i])) == 0) {
                  return found;
              }
          }
      }
  
      return NULL;
  }
  
  /*
  ** Select and copy the previous url on screen (do nothing if there's no url).
  **
  ** FIXME: doesn't handle urls that span multiple lines; will need to add support
  **        for multiline "getsel()" first
  */
  void
  copyurl(const Arg *arg) {
      /* () and [] can appear in urls, but excluding them here will reduce false
       * positives when figuring out where a given url ends.
       */
      static char URLCHARS[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
          "abcdefghijklmnopqrstuvwxyz"
          "0123456789-._~:/?#@!$&'*+,;=%";
  
      static const char* URLSTRINGS[] = {"http://", "https://"};
  
      /* remove highlighting from previous selection if any */
      if(sel.ob.x >= 0 && sel.oe.x >= 0)
          tsetcolor(sel.nb.y, sel.ob.x, sel.oe.x + 1, defaultfg, defaultbg);
  
      int i = 0,
          row = 0, /* row of current URL */
          col = 0, /* column of current URL start */
          startrow = 0, /* row of last occurrence */
          colend = 0, /* column of last occurrence */
          passes = 0; /* how many rows have been scanned */
  
      char *linestr = calloc(sizeof(char), term.col+1); /* assume ascii */
      char *c = NULL,
           *match = NULL;
  
      row = (sel.ob.x >= 0 && sel.nb.y > 0) ? sel.nb.y : term.bot;
      LIMIT(row, term.top, term.bot);
      startrow = row;
  
      colend = (sel.ob.x >= 0 && sel.nb.y > 0) ? sel.nb.x : term.col;
      LIMIT(colend, 0, term.col);
  
      /*
      ** Scan from (term.bot,term.col) to (0,0) and find
      ** next occurrance of a URL
      */
      while(passes !=term.bot + 2) {
          /* Read in each column of every row until
          ** we hit previous occurrence of URL
          */
          for (col = 0, i = 0; col < colend; ++col,++i) {
              /* assume ascii */
              if (term.line[row][col].u > 127)
                  continue;
              linestr[i] = term.line[row][col].u;
          }
          linestr[term.col] = '\0';
  
          if ((match = findlastany(linestr, URLSTRINGS,
                          sizeof(URLSTRINGS)/sizeof(URLSTRINGS[0]))))
              break;
  
          if (--row < term.top)
              row = term.bot;
  
          colend = term.col;
          passes++;
      };
  
      if (match) {
          /* must happen before trim */
          selclear();
          sel.ob.x = strlen(linestr) - strlen(match);
  
          /* trim the rest of the line from the url match */
          for (c = match; *c != '\0'; ++c)
              if (!strchr(URLCHARS, *c)) {
                  *c = '\0';
                  break;
              }
  
          /* highlight selection by inverting terminal colors */
          tsetcolor(row, sel.ob.x, sel.ob.x + strlen( match ), defaultbg, defaultfg);
  
          /* select and copy */
          sel.mode = 1;
          sel.type = SEL_REGULAR;
          sel.oe.x = sel.ob.x + strlen(match)-1;
          sel.ob.y = sel.oe.y = row;
          selnormalize();
          tsetdirt(sel.nb.y, sel.ne.y);
          xsetsel(getsel());
          xclipcopy();
      }
  
      free(linestr);
  }
  