hallo

1 files changed, 2801 insertions, 0 deletions

diff --git a/st.c b/st.c
new file mode 100755
index 0000000..97534b4
--- /dev/null
+++ b/st.c
@@ -0,0 +1,2801 @@
+/* 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"
+#define USE_ARGB (alpha != OPAQUE)
+
+#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 ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == 0x7f)
+#define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
+#define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
+#define ISDELIM(u)		(u && wcschr(worddelimiters, u))
+#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - \
+            term.scr + HISTSIZE + 1) % HISTSIZE] : \
+            term.line[(y) - term.scr])
+
+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,
+};
+
+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,  /* DCS, 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,
+};
+
+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;
+	Rune lastc;   /* last printed char outside of sequence, 0 if control */
+} Term;
+
+/* CSI Escape sequence structs */
+/* ESC '[' [[ [<priv>] <arg> [;]] <mode> [<mode>]] */
+typedef struct {
+	char buf[ESC_BUF_SIZ]; /* raw string */
+	size_t 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;             /* allocated raw string */
+	size_t siz;            /* allocation size */
+	size_t 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 void osc_color_response(int, int, int);
+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(const int *, int);
+static void tsetchar(Rune, const Glyph *, int, int);
+static void tsetdirt(int, int);
+static void tsetscroll(int, int);
+static void tswapscreen(void);
+static void tsetmode(int, int, const 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(const 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 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 const uchar utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
+static const uchar utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
+static const Rune utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
+static const 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(const char *s)
+{
+	char *p;
+
+	if ((p = strdup(s)) == NULL)
+		die("strdup: %s\n", strerror(errno));
+
+	return p;
+}
+
+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]);
+}
+
+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;
+}
+
+char
+base64dec_getc(const char **src)
+{
+	while (**src && !isprint((unsigned char)**src))
+		(*src)++;
+	return **src ? *((*src)++) : '=';  /* emulate padding if string ends */
+}
+
+char *
+base64dec(const char *src)
+{
+	size_t in_len = strlen(src);
+	char *result, *dst;
+	static const char base64_digits[256] = {
+		[43] = 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
+	};
+
+	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)];
+
+		/* invalid input. 'a' can be -1, e.g. if src is "\n" (c-str) */
+		if (a == -1 || b == -1)
+			break;
+
+		*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 || sel.mode == SEL_EMPTY)
+		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;
+	const 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;
+	const 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) || sel.type == SEL_RECTANGULAR))
+			*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, *arg;
+	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];
+		arg = NULL;
+	} else if (scroll) {
+		prog = scroll;
+		arg = utmp ? utmp : sh;
+	} else if (utmp) {
+		prog = utmp;
+		arg = NULL;
+	} else {
+		prog = sh;
+		arg = NULL;
+	}
+	DEFAULT(args, ((char *[]) {prog, arg, 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(const char *line, char *cmd, const 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);
+		close(m);
+		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));
+		if (s > 2)
+			close(s);
+#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 ret, written;
+
+	/* append read bytes to unprocessed bytes */
+	ret = read(cmdfd, buf+buflen, LEN(buf)-buflen);
+
+	switch (ret) {
+	case 0:
+		exit(0);
+	case -1:
+		die("couldn't read from shell: %s\n", strerror(errno));
+	default:
+		buflen += ret;
+		written = twrite(buf, buflen, 0);
+		buflen -= written;
+		/* keep any incomplete UTF-8 byte sequence 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(void)
+{
+	/* 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;
+	}
+
+	if (term.scr == 0)
+		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;
+	}
+
+	if (term.scr == 0)
+		selscroll(orig, -n);
+}
+
+void
+selscroll(int orig, int n)
+{
+	if (sel.ob.x == -1 || sel.alt != IS_SET(MODE_ALTSCREEN))
+		return;
+
+	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
+		selclear();
+	} else if (BETWEEN(sel.nb.y, orig, term.bot)) {
+		sel.ob.y += n;
+		sel.oe.y += n;
+		if (sel.ob.y < term.top || sel.ob.y > term.bot ||
+		    sel.oe.y < term.top || sel.oe.y > term.bot) {
+			selclear();
+		} else {
+			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;
+	int sep = ';'; /* colon or semi-colon, but not both */
+
+	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 (sep == ';' && *p == ':')
+			sep = ':'; /* allow override to colon once */
+		if (*p != sep || 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, const Glyph *attr, int x, int y)
+{
+	static const 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