scrolling added

6 files changed, 728 insertions, 129 deletions

diff --git a/Makefile b/Makefile
index 15db421..01e33ee 100644
--- a/Makefile
+++ b/Makefile
@@ -38,11 +38,6 @@ install: st
 	mkdir -p $(DESTDIR)$(PREFIX)/bin
 	cp -f st $(DESTDIR)$(PREFIX)/bin
 	chmod 755 $(DESTDIR)$(PREFIX)/bin/st
-	mkdir -p $(DESTDIR)$(MANPREFIX)/man1
-	sed "s/VERSION/$(VERSION)/g" < st.1 > $(DESTDIR)$(MANPREFIX)/man1/st.1
-	chmod 644 $(DESTDIR)$(MANPREFIX)/man1/st.1
-	tic -sx st.info
-	@echo Please see the README file regarding the terminfo entry of st.
 
 uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/st
diff --git a/config.def.h b/config.def.h
index 2cd740a..122c00d 100644
--- a/config.def.h
+++ b/config.def.h
@@ -176,11 +176,13 @@ static uint forcemousemod = ShiftMask;
  */
 static MouseShortcut mshortcuts[] = {
 	/* mask                 button   function        argument       release */
+	{ XK_NO_MOD,            Button4, kscrollup,      {.i = 1} },
+	{ XK_NO_MOD,            Button5, kscrolldown,    {.i = 1} },
 	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
-	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
-	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
-	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
-	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
+//	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
+//	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
+//	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
+//	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
 };
 
 /* Internal keyboard shortcuts. */
@@ -201,6 +203,8 @@ static Shortcut shortcuts[] = {
 	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
+	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
 };
 
 /*
diff --git a/config.h b/config.h
new file mode 100644
index 0000000..122c00d
--- /dev/null
+++ b/config.h
@@ -0,0 +1,478 @@
+/* See LICENSE file for copyright and license details. */
+
+/*
+ * appearance
+ *
+ * font: see http://freedesktop.org/software/fontconfig/fontconfig-user.html
+ */
+static char *font = "Liberation Mono:pixelsize=12:antialias=true:autohint=true";
+static int borderpx = 2;
+
+/*
+ * What program is execed by st depends of these precedence rules:
+ * 1: program passed with -e
+ * 2: scroll and/or utmp
+ * 3: SHELL environment variable
+ * 4: value of shell in /etc/passwd
+ * 5: value of shell in config.h
+ */
+static char *shell = "/bin/sh";
+char *utmp = NULL;
+/* scroll program: to enable use a string like "scroll" */
+char *scroll = NULL;
+char *stty_args = "stty raw pass8 nl -echo -iexten -cstopb 38400";
+
+/* identification sequence returned in DA and DECID */
+char *vtiden = "\033[?6c";
+
+/* Kerning / character bounding-box multipliers */
+static float cwscale = 1.0;
+static float chscale = 1.0;
+
+/*
+ * word delimiter string
+ *
+ * More advanced example: L" `'\"()[]{}"
+ */
+wchar_t *worddelimiters = L" ";
+
+/* selection timeouts (in milliseconds) */
+static unsigned int doubleclicktimeout = 300;
+static unsigned int tripleclicktimeout = 600;
+
+/* alt screens */
+int allowaltscreen = 1;
+
+/* allow certain non-interactive (insecure) window operations such as:
+   setting the clipboard text */
+int allowwindowops = 0;
+
+/*
+ * draw latency range in ms - from new content/keypress/etc until drawing.
+ * within this range, st draws when content stops arriving (idle). mostly it's
+ * near minlatency, but it waits longer for slow updates to avoid partial draw.
+ * low minlatency will tear/flicker more, as it can "detect" idle too early.
+ */
+static double minlatency = 2;
+static double maxlatency = 33;
+
+/*
+ * blinking timeout (set to 0 to disable blinking) for the terminal blinking
+ * attribute.
+ */
+static unsigned int blinktimeout = 800;
+
+/*
+ * thickness of underline and bar cursors
+ */
+static unsigned int cursorthickness = 2;
+
+/*
+ * bell volume. It must be a value between -100 and 100. Use 0 for disabling
+ * it
+ */
+static int bellvolume = 0;
+
+/* default TERM value */
+char *termname = "st-256color";
+
+/*
+ * spaces per tab
+ *
+ * When you are changing this value, don't forget to adapt the »it« value in
+ * the st.info and appropriately install the st.info in the environment where
+ * you use this st version.
+ *
+ *	it#$tabspaces,
+ *
+ * Secondly make sure your kernel is not expanding tabs. When running `stty
+ * -a` »tab0« should appear. You can tell the terminal to not expand tabs by
+ *  running following command:
+ *
+ *	stty tabs
+ */
+unsigned int tabspaces = 8;
+
+/* Terminal colors (16 first used in escape sequence) */
+static const char *colorname[] = {
+	/* 8 normal colors */
+	"black",
+	"red3",
+	"green3",
+	"yellow3",
+	"blue2",
+	"magenta3",
+	"cyan3",
+	"gray90",
+
+	/* 8 bright colors */
+	"gray50",
+	"red",
+	"green",
+	"yellow",
+	"#5c5cff",
+	"magenta",
+	"cyan",
+	"white",
+
+	[255] = 0,
+
+	/* more colors can be added after 255 to use with DefaultXX */
+	"#cccccc",
+	"#555555",
+	"gray90", /* default foreground colour */
+	"black", /* default background colour */
+};
+
+
+/*
+ * Default colors (colorname index)
+ * foreground, background, cursor, reverse cursor
+ */
+unsigned int defaultfg = 258;
+unsigned int defaultbg = 259;
+unsigned int defaultcs = 256;
+static unsigned int defaultrcs = 257;
+
+/*
+ * Default shape of cursor
+ * 2: Block ("█")
+ * 4: Underline ("_")
+ * 6: Bar ("|")
+ * 7: Snowman ("☃")
+ */
+static unsigned int cursorshape = 2;
+
+/*
+ * Default columns and rows numbers
+ */
+
+static unsigned int cols = 80;
+static unsigned int rows = 24;
+
+/*
+ * Default colour and shape of the mouse cursor
+ */
+static unsigned int mouseshape = XC_xterm;
+static unsigned int mousefg = 7;
+static unsigned int mousebg = 0;
+
+/*
+ * Color used to display font attributes when fontconfig selected a font which
+ * doesn't match the ones requested.
+ */
+static unsigned int defaultattr = 11;
+
+/*
+ * Force mouse select/shortcuts while mask is active (when MODE_MOUSE is set).
+ * Note that if you want to use ShiftMask with selmasks, set this to an other
+ * modifier, set to 0 to not use it.
+ */
+static uint forcemousemod = ShiftMask;
+
+/*
+ * Internal mouse shortcuts.
+ * Beware that overloading Button1 will disable the selection.
+ */
+static MouseShortcut mshortcuts[] = {
+	/* mask                 button   function        argument       release */
+	{ XK_NO_MOD,            Button4, kscrollup,      {.i = 1} },
+	{ XK_NO_MOD,            Button5, kscrolldown,    {.i = 1} },
+	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
+//	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
+//	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
+//	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
+//	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
+};
+
+/* Internal keyboard shortcuts. */
+#define MODKEY Mod1Mask
+#define TERMMOD (ControlMask|ShiftMask)
+
+static Shortcut shortcuts[] = {
+	/* mask                 keysym          function        argument */
+	{ XK_ANY_MOD,           XK_Break,       sendbreak,      {.i =  0} },
+	{ ControlMask,          XK_Print,       toggleprinter,  {.i =  0} },
+	{ ShiftMask,            XK_Print,       printscreen,    {.i =  0} },
+	{ XK_ANY_MOD,           XK_Print,       printsel,       {.i =  0} },
+	{ TERMMOD,              XK_Prior,       zoom,           {.f = +1} },
+	{ TERMMOD,              XK_Next,        zoom,           {.f = -1} },
+	{ TERMMOD,              XK_Home,        zoomreset,      {.f =  0} },
+	{ TERMMOD,              XK_C,           clipcopy,       {.i =  0} },
+	{ TERMMOD,              XK_V,           clippaste,      {.i =  0} },
+	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
+	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
+	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
+	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
+};
+
+/*
+ * Special keys (change & recompile st.info accordingly)
+ *
+ * Mask value:
+ * * Use XK_ANY_MOD to match the key no matter modifiers state
+ * * Use XK_NO_MOD to match the key alone (no modifiers)
+ * appkey value:
+ * * 0: no value
+ * * > 0: keypad application mode enabled
+ * *   = 2: term.numlock = 1
+ * * < 0: keypad application mode disabled
+ * appcursor value:
+ * * 0: no value
+ * * > 0: cursor application mode enabled
+ * * < 0: cursor application mode disabled
+ *
+ * Be careful with the order of the definitions because st searches in
+ * this table sequentially, so any XK_ANY_MOD must be in the last
+ * position for a key.
+ */
+
+/*
+ * If you want keys other than the X11 function keys (0xFD00 - 0xFFFF)
+ * to be mapped below, add them to this array.
+ */
+static KeySym mappedkeys[] = { -1 };
+
+/*
+ * State bits to ignore when matching key or button events.  By default,
+ * numlock (Mod2Mask) and keyboard layout (XK_SWITCH_MOD) are ignored.
+ */
+static uint ignoremod = Mod2Mask|XK_SWITCH_MOD;
+
+/*
+ * This is the huge key array which defines all compatibility to the Linux
+ * world. Please decide about changes wisely.
+ */
+static Key key[] = {
+	/* keysym           mask            string      appkey appcursor */
+	{ XK_KP_Home,       ShiftMask,      "\033[2J",       0,   -1},
+	{ XK_KP_Home,       ShiftMask,      "\033[1;2H",     0,   +1},
+	{ XK_KP_Home,       XK_ANY_MOD,     "\033[H",        0,   -1},
+	{ XK_KP_Home,       XK_ANY_MOD,     "\033[1~",       0,   +1},
+	{ XK_KP_Up,         XK_ANY_MOD,     "\033Ox",       +1,    0},
+	{ XK_KP_Up,         XK_ANY_MOD,     "\033[A",        0,   -1},
+	{ XK_KP_Up,         XK_ANY_MOD,     "\033OA",        0,   +1},
+	{ XK_KP_Down,       XK_ANY_MOD,     "\033Or",       +1,    0},
+	{ XK_KP_Down,       XK_ANY_MOD,     "\033[B",        0,   -1},
+	{ XK_KP_Down,       XK_ANY_MOD,     "\033OB",        0,   +1},
+	{ XK_KP_Left,       XK_ANY_MOD,     "\033Ot",       +1,    0},
+	{ XK_KP_Left,       XK_ANY_MOD,     "\033[D",        0,   -1},
+	{ XK_KP_Left,       XK_ANY_MOD,     "\033OD",        0,   +1},
+	{ XK_KP_Right,      XK_ANY_MOD,     "\033Ov",       +1,    0},
+	{ XK_KP_Right,      XK_ANY_MOD,     "\033[C",        0,   -1},
+	{ XK_KP_Right,      XK_ANY_MOD,     "\033OC",        0,   +1},
+	{ XK_KP_Prior,      ShiftMask,      "\033[5;2~",     0,    0},
+	{ XK_KP_Prior,      XK_ANY_MOD,     "\033[5~",       0,    0},
+	{ XK_KP_Begin,      XK_ANY_MOD,     "\033[E",        0,    0},
+	{ XK_KP_End,        ControlMask,    "\033[J",       -1,    0},
+	{ XK_KP_End,        ControlMask,    "\033[1;5F",    +1,    0},
+	{ XK_KP_End,        ShiftMask,      "\033[K",       -1,    0},
+	{ XK_KP_End,        ShiftMask,      "\033[1;2F",    +1,    0},
+	{ XK_KP_End,        XK_ANY_MOD,     "\033[4~",       0,    0},
+	{ XK_KP_Next,       ShiftMask,      "\033[6;2~",     0,    0},
+	{ XK_KP_Next,       XK_ANY_MOD,     "\033[6~",       0,    0},
+	{ XK_KP_Insert,     ShiftMask,      "\033[2;2~",    +1,    0},
+	{ XK_KP_Insert,     ShiftMask,      "\033[4l",      -1,    0},
+	{ XK_KP_Insert,     ControlMask,    "\033[L",       -1,    0},
+	{ XK_KP_Insert,     ControlMask,    "\033[2;5~",    +1,    0},
+	{ XK_KP_Insert,     XK_ANY_MOD,     "\033[4h",      -1,    0},
+	{ XK_KP_Insert,     XK_ANY_MOD,     "\033[2~",      +1,    0},
+	{ XK_KP_Delete,     ControlMask,    "\033[M",       -1,    0},
+	{ XK_KP_Delete,     ControlMask,    "\033[3;5~",    +1,    0},
+	{ XK_KP_Delete,     ShiftMask,      "\033[2K",      -1,    0},
+	{ XK_KP_Delete,     ShiftMask,      "\033[3;2~",    +1,    0},
+	{ XK_KP_Delete,     XK_ANY_MOD,     "\033[P",       -1,    0},
+	{ XK_KP_Delete,     XK_ANY_MOD,     "\033[3~",      +1,    0},
+	{ XK_KP_Multiply,   XK_ANY_MOD,     "\033Oj",       +2,    0},
+	{ XK_KP_Add,        XK_ANY_MOD,     "\033Ok",       +2,    0},
+	{ XK_KP_Enter,      XK_ANY_MOD,     "\033OM",       +2,    0},
+	{ XK_KP_Enter,      XK_ANY_MOD,     "\r",           -1,    0},
+	{ XK_KP_Subtract,   XK_ANY_MOD,     "\033Om",       +2,    0},
+	{ XK_KP_Decimal,    XK_ANY_MOD,     "\033On",       +2,    0},
+	{ XK_KP_Divide,     XK_ANY_MOD,     "\033Oo",       +2,    0},
+	{ XK_KP_0,          XK_ANY_MOD,     "\033Op",       +2,    0},
+	{ XK_KP_1,          XK_ANY_MOD,     "\033Oq",       +2,    0},
+	{ XK_KP_2,          XK_ANY_MOD,     "\033Or",       +2,    0},
+	{ XK_KP_3,          XK_ANY_MOD,     "\033Os",       +2,    0},
+	{ XK_KP_4,          XK_ANY_MOD,     "\033Ot",       +2,    0},
+	{ XK_KP_5,          XK_ANY_MOD,     "\033Ou",       +2,    0},
+	{ XK_KP_6,          XK_ANY_MOD,     "\033Ov",       +2,    0},
+	{ XK_KP_7,          XK_ANY_MOD,     "\033Ow",       +2,    0},
+	{ XK_KP_8,          XK_ANY_MOD,     "\033Ox",       +2,    0},
+	{ XK_KP_9,          XK_ANY_MOD,     "\033Oy",       +2,    0},
+	{ XK_Up,            ShiftMask,      "\033[1;2A",     0,    0},
+	{ XK_Up,            Mod1Mask,       "\033[1;3A",     0,    0},
+	{ XK_Up,         ShiftMask|Mod1Mask,"\033[1;4A",     0,    0},
+	{ XK_Up,            ControlMask,    "\033[1;5A",     0,    0},
+	{ XK_Up,      ShiftMask|ControlMask,"\033[1;6A",     0,    0},
+	{ XK_Up,       ControlMask|Mod1Mask,"\033[1;7A",     0,    0},
+	{ XK_Up,ShiftMask|ControlMask|Mod1Mask,"\033[1;8A",  0,    0},
+	{ XK_Up,            XK_ANY_MOD,     "\033[A",        0,   -1},
+	{ XK_Up,            XK_ANY_MOD,     "\033OA",        0,   +1},
+	{ XK_Down,          ShiftMask,      "\033[1;2B",     0,    0},
+	{ XK_Down,          Mod1Mask,       "\033[1;3B",     0,    0},
+	{ XK_Down,       ShiftMask|Mod1Mask,"\033[1;4B",     0,    0},
+	{ XK_Down,          ControlMask,    "\033[1;5B",     0,    0},
+	{ XK_Down,    ShiftMask|ControlMask,"\033[1;6B",     0,    0},
+	{ XK_Down,     ControlMask|Mod1Mask,"\033[1;7B",     0,    0},
+	{ XK_Down,ShiftMask|ControlMask|Mod1Mask,"\033[1;8B",0,    0},
+	{ XK_Down,          XK_ANY_MOD,     "\033[B",        0,   -1},
+	{ XK_Down,          XK_ANY_MOD,     "\033OB",        0,   +1},
+	{ XK_Left,          ShiftMask,      "\033[1;2D",     0,    0},
+	{ XK_Left,          Mod1Mask,       "\033[1;3D",     0,    0},
+	{ XK_Left,       ShiftMask|Mod1Mask,"\033[1;4D",     0,    0},
+	{ XK_Left,          ControlMask,    "\033[1;5D",     0,    0},
+	{ XK_Left,    ShiftMask|ControlMask,"\033[1;6D",     0,    0},
+	{ XK_Left,     ControlMask|Mod1Mask,"\033[1;7D",     0,    0},
+	{ XK_Left,ShiftMask|ControlMask|Mod1Mask,"\033[1;8D",0,    0},
+	{ XK_Left,          XK_ANY_MOD,     "\033[D",        0,   -1},
+	{ XK_Left,          XK_ANY_MOD,     "\033OD",        0,   +1},
+	{ XK_Right,         ShiftMask,      "\033[1;2C",     0,    0},
+	{ XK_Right,         Mod1Mask,       "\033[1;3C",     0,    0},
+	{ XK_Right,      ShiftMask|Mod1Mask,"\033[1;4C",     0,    0},
+	{ XK_Right,         ControlMask,    "\033[1;5C",     0,    0},
+	{ XK_Right,   ShiftMask|ControlMask,"\033[1;6C",     0,    0},
+	{ XK_Right,    ControlMask|Mod1Mask,"\033[1;7C",     0,    0},
+	{ XK_Right,ShiftMask|ControlMask|Mod1Mask,"\033[1;8C",0,   0},
+	{ XK_Right,         XK_ANY_MOD,     "\033[C",        0,   -1},
+	{ XK_Right,         XK_ANY_MOD,     "\033OC",        0,   +1},
+	{ XK_ISO_Left_Tab,  ShiftMask,      "\033[Z",        0,    0},
+	{ XK_Return,        Mod1Mask,       "\033\r",        0,    0},
+	{ XK_Return,        XK_ANY_MOD,     "\r",            0,    0},
+	{ XK_Insert,        ShiftMask,      "\033[4l",      -1,    0},
+	{ XK_Insert,        ShiftMask,      "\033[2;2~",    +1,    0},
+	{ XK_Insert,        ControlMask,    "\033[L",       -1,    0},
+	{ XK_Insert,        ControlMask,    "\033[2;5~",    +1,    0},
+	{ XK_Insert,        XK_ANY_MOD,     "\033[4h",      -1,    0},
+	{ XK_Insert,        XK_ANY_MOD,     "\033[2~",      +1,    0},
+	{ XK_Delete,        ControlMask,    "\033[M",       -1,    0},
+	{ XK_Delete,        ControlMask,    "\033[3;5~",    +1,    0},
+	{ XK_Delete,        ShiftMask,      "\033[2K",      -1,    0},
+	{ XK_Delete,        ShiftMask,      "\033[3;2~",    +1,    0},
+	{ XK_Delete,        XK_ANY_MOD,     "\033[P",       -1,    0},
+	{ XK_Delete,        XK_ANY_MOD,     "\033[3~",      +1,    0},
+	{ XK_BackSpace,     XK_NO_MOD,      "\177",          0,    0},
+	{ XK_BackSpace,     Mod1Mask,       "\033\177",      0,    0},
+	{ XK_Home,          ShiftMask,      "\033[2J",       0,   -1},
+	{ XK_Home,          ShiftMask,      "\033[1;2H",     0,   +1},
+	{ XK_Home,          XK_ANY_MOD,     "\033[H",        0,   -1},
+	{ XK_Home,          XK_ANY_MOD,     "\033[1~",       0,   +1},
+	{ XK_End,           ControlMask,    "\033[J",       -1,    0},
+	{ XK_End,           ControlMask,    "\033[1;5F",    +1,    0},
+	{ XK_End,           ShiftMask,      "\033[K",       -1,    0},
+	{ XK_End,           ShiftMask,      "\033[1;2F",    +1,    0},
+	{ XK_End,           XK_ANY_MOD,     "\033[4~",       0,    0},
+	{ XK_Prior,         ControlMask,    "\033[5;5~",     0,    0},
+	{ XK_Prior,         ShiftMask,      "\033[5;2~",     0,    0},
+	{ XK_Prior,         XK_ANY_MOD,     "\033[5~",       0,    0},
+	{ XK_Next,          ControlMask,    "\033[6;5~",     0,    0},
+	{ XK_Next,          ShiftMask,      "\033[6;2~",     0,    0},
+	{ XK_Next,          XK_ANY_MOD,     "\033[6~",       0,    0},
+	{ XK_F1,            XK_NO_MOD,      "\033OP" ,       0,    0},
+	{ XK_F1, /* F13 */  ShiftMask,      "\033[1;2P",     0,    0},
+	{ XK_F1, /* F25 */  ControlMask,    "\033[1;5P",     0,    0},
+	{ XK_F1, /* F37 */  Mod4Mask,       "\033[1;6P",     0,    0},
+	{ XK_F1, /* F49 */  Mod1Mask,       "\033[1;3P",     0,    0},
+	{ XK_F1, /* F61 */  Mod3Mask,       "\033[1;4P",     0,    0},
+	{ XK_F2,            XK_NO_MOD,      "\033OQ" ,       0,    0},
+	{ XK_F2, /* F14 */  ShiftMask,      "\033[1;2Q",     0,    0},
+	{ XK_F2, /* F26 */  ControlMask,    "\033[1;5Q",     0,    0},
+	{ XK_F2, /* F38 */  Mod4Mask,       "\033[1;6Q",     0,    0},
+	{ XK_F2, /* F50 */  Mod1Mask,       "\033[1;3Q",     0,    0},
+	{ XK_F2, /* F62 */  Mod3Mask,       "\033[1;4Q",     0,    0},
+	{ XK_F3,            XK_NO_MOD,      "\033OR" ,       0,    0},
+	{ XK_F3, /* F15 */  ShiftMask,      "\033[1;2R",     0,    0},
+	{ XK_F3, /* F27 */  ControlMask,    "\033[1;5R",     0,    0},
+	{ XK_F3, /* F39 */  Mod4Mask,       "\033[1;6R",     0,    0},
+	{ XK_F3, /* F51 */  Mod1Mask,       "\033[1;3R",     0,    0},
+	{ XK_F3, /* F63 */  Mod3Mask,       "\033[1;4R",     0,    0},
+	{ XK_F4,            XK_NO_MOD,      "\033OS" ,       0,    0},
+	{ XK_F4, /* F16 */  ShiftMask,      "\033[1;2S",     0,    0},
+	{ XK_F4, /* F28 */  ControlMask,    "\033[1;5S",     0,    0},
+	{ XK_F4, /* F40 */  Mod4Mask,       "\033[1;6S",     0,    0},
+	{ XK_F4, /* F52 */  Mod1Mask,       "\033[1;3S",     0,    0},
+	{ XK_F5,            XK_NO_MOD,      "\033[15~",      0,    0},
+	{ XK_F5, /* F17 */  ShiftMask,      "\033[15;2~",    0,    0},
+	{ XK_F5, /* F29 */  ControlMask,    "\033[15;5~",    0,    0},
+	{ XK_F5, /* F41 */  Mod4Mask,       "\033[15;6~",    0,    0},
+	{ XK_F5, /* F53 */  Mod1Mask,       "\033[15;3~",    0,    0},
+	{ XK_F6,            XK_NO_MOD,      "\033[17~",      0,    0},
+	{ XK_F6, /* F18 */  ShiftMask,      "\033[17;2~",    0,    0},
+	{ XK_F6, /* F30 */  ControlMask,    "\033[17;5~",    0,    0},
+	{ XK_F6, /* F42 */  Mod4Mask,       "\033[17;6~",    0,    0},
+	{ XK_F6, /* F54 */  Mod1Mask,       "\033[17;3~",    0,    0},
+	{ XK_F7,            XK_NO_MOD,      "\033[18~",      0,    0},
+	{ XK_F7, /* F19 */  ShiftMask,      "\033[18;2~",    0,    0},
+	{ XK_F7, /* F31 */  ControlMask,    "\033[18;5~",    0,    0},
+	{ XK_F7, /* F43 */  Mod4Mask,       "\033[18;6~",    0,    0},
+	{ XK_F7, /* F55 */  Mod1Mask,       "\033[18;3~",    0,    0},
+	{ XK_F8,            XK_NO_MOD,      "\033[19~",      0,    0},
+	{ XK_F8, /* F20 */  ShiftMask,      "\033[19;2~",    0,    0},
+	{ XK_F8, /* F32 */  ControlMask,    "\033[19;5~",    0,    0},
+	{ XK_F8, /* F44 */  Mod4Mask,       "\033[19;6~",    0,    0},
+	{ XK_F8, /* F56 */  Mod1Mask,       "\033[19;3~",    0,    0},
+	{ XK_F9,            XK_NO_MOD,      "\033[20~",      0,    0},
+	{ XK_F9, /* F21 */  ShiftMask,      "\033[20;2~",    0,    0},
+	{ XK_F9, /* F33 */  ControlMask,    "\033[20;5~",    0,    0},
+	{ XK_F9, /* F45 */  Mod4Mask,       "\033[20;6~",    0,    0},
+	{ XK_F9, /* F57 */  Mod1Mask,       "\033[20;3~",    0,    0},
+	{ XK_F10,           XK_NO_MOD,      "\033[21~",      0,    0},
+	{ XK_F10, /* F22 */ ShiftMask,      "\033[21;2~",    0,    0},
+	{ XK_F10, /* F34 */ ControlMask,    "\033[21;5~",    0,    0},
+	{ XK_F10, /* F46 */ Mod4Mask,       "\033[21;6~",    0,    0},
+	{ XK_F10, /* F58 */ Mod1Mask,       "\033[21;3~",    0,    0},
+	{ XK_F11,           XK_NO_MOD,      "\033[23~",      0,    0},
+	{ XK_F11, /* F23 */ ShiftMask,      "\033[23;2~",    0,    0},
+	{ XK_F11, /* F35 */ ControlMask,    "\033[23;5~",    0,    0},
+	{ XK_F11, /* F47 */ Mod4Mask,       "\033[23;6~",    0,    0},
+	{ XK_F11, /* F59 */ Mod1Mask,       "\033[23;3~",    0,    0},
+	{ XK_F12,           XK_NO_MOD,      "\033[24~",      0,    0},
+	{ XK_F12, /* F24 */ ShiftMask,      "\033[24;2~",    0,    0},
+	{ XK_F12, /* F36 */ ControlMask,    "\033[24;5~",    0,    0},
+	{ XK_F12, /* F48 */ Mod4Mask,       "\033[24;6~",    0,    0},
+	{ XK_F12, /* F60 */ Mod1Mask,       "\033[24;3~",    0,    0},
+	{ XK_F13,           XK_NO_MOD,      "\033[1;2P",     0,    0},
+	{ XK_F14,           XK_NO_MOD,      "\033[1;2Q",     0,    0},
+	{ XK_F15,           XK_NO_MOD,      "\033[1;2R",     0,    0},
+	{ XK_F16,           XK_NO_MOD,      "\033[1;2S",     0,    0},
+	{ XK_F17,           XK_NO_MOD,      "\033[15;2~",    0,    0},
+	{ XK_F18,           XK_NO_MOD,      "\033[17;2~",    0,    0},
+	{ XK_F19,           XK_NO_MOD,      "\033[18;2~",    0,    0},
+	{ XK_F20,           XK_NO_MOD,      "\033[19;2~",    0,    0},
+	{ XK_F21,           XK_NO_MOD,      "\033[20;2~",    0,    0},
+	{ XK_F22,           XK_NO_MOD,      "\033[21;2~",    0,    0},
+	{ XK_F23,           XK_NO_MOD,      "\033[23;2~",    0,    0},
+	{ XK_F24,           XK_NO_MOD,      "\033[24;2~",    0,    0},
+	{ XK_F25,           XK_NO_MOD,      "\033[1;5P",     0,    0},
+	{ XK_F26,           XK_NO_MOD,      "\033[1;5Q",     0,    0},
+	{ XK_F27,           XK_NO_MOD,      "\033[1;5R",     0,    0},
+	{ XK_F28,           XK_NO_MOD,      "\033[1;5S",     0,    0},
+	{ XK_F29,           XK_NO_MOD,      "\033[15;5~",    0,    0},
+	{ XK_F30,           XK_NO_MOD,      "\033[17;5~",    0,    0},
+	{ XK_F31,           XK_NO_MOD,      "\033[18;5~",    0,    0},
+	{ XK_F32,           XK_NO_MOD,      "\033[19;5~",    0,    0},
+	{ XK_F33,           XK_NO_MOD,      "\033[20;5~",    0,    0},
+	{ XK_F34,           XK_NO_MOD,      "\033[21;5~",    0,    0},
+	{ XK_F35,           XK_NO_MOD,      "\033[23;5~",    0,    0},
+};
+
+/*
+ * Selection types' masks.
+ * Use the same masks as usual.
+ * Button1Mask is always unset, to make masks match between ButtonPress.
+ * ButtonRelease and MotionNotify.
+ * If no match is found, regular selection is used.
+ */
+static uint selmasks[] = {
+	[SEL_RECTANGULAR] = Mod1Mask,
+};
+
+/*
+ * Printable characters in ASCII, used to estimate the advance width
+ * of single wide characters.
+ */
+static char ascii_printable[] =
+	" !\"#$%&'()*+,-./0123456789:;<=>?"
+	"@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_"
+	"`abcdefghijklmnopqrstuvwxyz{|}~";
diff --git a/st.c b/st.c
index b9f66e7..d9b163e 100644
--- a/st.c
+++ b/st.c
@@ -43,6 +43,10 @@
 #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
 #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
 
+#define TSCREEN term.screen[IS_SET(MODE_ALTSCREEN)]
+#define TLINEOFFSET(y) (((y) + TSCREEN.cur - TSCREEN.off + TSCREEN.size) % TSCREEN.size)
+#define TLINE(y) (TSCREEN.buffer[TLINEOFFSET(y)])
+
 enum term_mode {
 	MODE_WRAP        = 1 << 0,
 	MODE_INSERT      = 1 << 1,
@@ -109,12 +113,21 @@ typedef struct {
 	int alt;
 } Selection;
 
+/* Screen lines */
+typedef struct {
+	Line* buffer;  /* ring buffer */
+	int size;      /* size of buffer */
+	int cur;       /* start of active screen */
+	int off;       /* scrollback line offset */
+	TCursor sc;    /* saved cursor */
+} LineBuffer;
+
 /* Internal representation of the screen */
 typedef struct {
 	int row;      /* nb row */
 	int col;      /* nb col */
-	Line *line;   /* screen */
-	Line *alt;    /* alternate screen */
+	LineBuffer screen[2]; /* screen and alternate screen */
+	int linelen;  /* allocated line length */
 	int *dirty;   /* dirtyness of lines */
 	TCursor c;    /* cursor */
 	int ocx;      /* old cursor col */
@@ -203,6 +216,8 @@ static void tdeftran(char);
 static void tstrsequence(uchar);
 
 static void drawregion(int, int, int, int);
+static void clearline(Line, Glyph, int, int);
+static Line ensureline(Line);
 
 static void selnormalize(void);
 static void selscroll(int, int);
@@ -408,11 +423,12 @@ int
 tlinelen(int y)
 {
 	int i = term.col;
+	Line line = TLINE(y);
 
-	if (term.line[y][i - 1].mode & ATTR_WRAP)
+	if (line[i - 1].mode & ATTR_WRAP)
 		return i;
 
-	while (i > 0 && term.line[y][i - 1].u == ' ')
+	while (i > 0 && line[i - 1].u == ' ')
 		--i;
 
 	return i;
@@ -521,7 +537,7 @@ selsnap(int *x, int *y, int direction)
 		 * Snap around if the word wraps around at the end or
 		 * beginning of a line.
 		 */
-		prevgp = &term.line[*y][*x];
+		prevgp = &TLINE(*y)[*x];
 		prevdelim = ISDELIM(prevgp->u);
 		for (;;) {
 			newx = *x + direction;
@@ -536,14 +552,14 @@ selsnap(int *x, int *y, int direction)
 					yt = *y, xt = *x;
 				else
 					yt = newy, xt = newx;
-				if (!(term.line[yt][xt].mode & ATTR_WRAP))
+				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
 					break;
 			}
 
 			if (newx >= tlinelen(newy))
 				break;
 
-			gp = &term.line[newy][newx];
+			gp = &TLINE(newy)[newx];
 			delim = ISDELIM(gp->u);
 			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
 					|| (delim && gp->u != prevgp->u)))
@@ -564,14 +580,14 @@ selsnap(int *x, int *y, int direction)
 		*x = (direction < 0) ? 0 : term.col - 1;
 		if (direction < 0) {
 			for (; *y > 0; *y += direction) {
-				if (!(term.line[*y-1][term.col-1].mode
+				if (!(TLINE(*y-1)[term.col-1].mode
 						& ATTR_WRAP)) {
 					break;
 				}
 			}
 		} else if (direction > 0) {
 			for (; *y < term.row-1; *y += direction) {
-				if (!(term.line[*y][term.col-1].mode
+				if (!(TLINE(*y)[term.col-1].mode
 						& ATTR_WRAP)) {
 					break;
 				}
@@ -602,13 +618,13 @@ getsel(void)
 		}
 
 		if (sel.type == SEL_RECTANGULAR) {
-			gp = &term.line[y][sel.nb.x];
+			gp = &TLINE(y)[sel.nb.x];
 			lastx = sel.ne.x;
 		} else {
-			gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
+			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
 			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
 		}
-		last = &term.line[y][MIN(lastx, linelen-1)];
+		last = &TLINE(y)[MIN(lastx, linelen-1)];
 		while (last >= gp && last->u == ' ')
 			--last;
 
@@ -949,12 +965,15 @@ int
 tattrset(int attr)
 {
 	int i, j;
+	int y = TLINEOFFSET(0);
 
 	for (i = 0; i < term.row-1; i++) {
+		Line line = TSCREEN.buffer[y];
 		for (j = 0; j < term.col-1; j++) {
-			if (term.line[i][j].mode & attr)
+			if (line[j].mode & attr)
 				return 1;
 		}
+		y = (y+1) % TSCREEN.size;
 	}
 
 	return 0;
@@ -976,14 +995,17 @@ void
 tsetdirtattr(int attr)
 {
 	int i, j;
+	int y = TLINEOFFSET(0);
 
 	for (i = 0; i < term.row-1; i++) {
+		Line line = TSCREEN.buffer[y];
 		for (j = 0; j < term.col-1; j++) {
-			if (term.line[i][j].mode & attr) {
+			if (line[j].mode & attr) {
 				tsetdirt(i, i);
 				break;
 			}
 		}
+		y = (y+1) % TSCREEN.size;
 	}
 }
 
@@ -996,27 +1018,19 @@ tfulldirt(void)
 void
 tcursor(int mode)
 {
-	static TCursor c[2];
-	int alt = IS_SET(MODE_ALTSCREEN);
-
 	if (mode == CURSOR_SAVE) {
-		c[alt] = term.c;
+		TSCREEN.sc = term.c;
 	} else if (mode == CURSOR_LOAD) {
-		term.c = c[alt];
-		tmoveto(c[alt].x, c[alt].y);
+		term.c = TSCREEN.sc;
+		tmoveto(term.c.x, term.c.y);
 	}
 }
 
 void
 treset(void)
 {
-	uint i;
-
-	term.c = (TCursor){{
-		.mode = ATTR_NULL,
-		.fg = defaultfg,
-		.bg = defaultbg
-	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
+	int i, j;
+	Glyph g = (Glyph){ .fg = defaultfg, .bg = defaultbg};
 
 	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
 	for (i = tabspaces; i < term.col; i += tabspaces)
@@ -1028,17 +1042,37 @@ treset(void)
 	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();
+		term.screen[i].sc = (TCursor){{
+			.fg = defaultfg,
+			.bg = defaultbg
+		}};
+		term.screen[i].cur = 0;
+		term.screen[i].off = 0;
+		for (j = 0; j < term.row; ++j) {
+			if (term.col != term.linelen)
+				term.screen[i].buffer[j] = xrealloc(term.screen[i].buffer[j], term.col * sizeof(Glyph));
+			clearline(term.screen[i].buffer[j], g, 0, term.col);
+		}
+		for (j = term.row; j < term.screen[i].size; ++j) {
+			free(term.screen[i].buffer[j]);
+			term.screen[i].buffer[j] = NULL;
+		}
 	}
+	tcursor(CURSOR_LOAD);
+	term.linelen = term.col;
+	tfulldirt();
 }
 
 void
 tnew(int col, int row)
 {
-	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
+	int i;
+	term = (Term){};
+	term.screen[0].buffer = xmalloc(HISTSIZE * sizeof(Line));
+	term.screen[0].size = HISTSIZE;
+	term.screen[1].buffer = NULL;
+	for (i = 0; i < HISTSIZE; ++i) term.screen[0].buffer[i] = NULL;
+
 	tresize(col, row);
 	treset();
 }
@@ -1046,15 +1080,43 @@ tnew(int col, int row)
 void
 tswapscreen(void)
 {
-	Line *tmp = term.line;
-
-	term.line = term.alt;
-	term.alt = tmp;
 	term.mode ^= MODE_ALTSCREEN;
 	tfulldirt();
 }
 
 void
+kscrollup(const Arg *a)
+{
+	int n = a->i;
+
+	if (IS_SET(MODE_ALTSCREEN))
+		return;
+
+	if (n < 0) n = (-n) * term.row;
+	if (n > TSCREEN.size - term.row - TSCREEN.off) n = TSCREEN.size - term.row - TSCREEN.off;
+	while (!TLINE(-n)) --n;
+	TSCREEN.off += n;
+	selscroll(0, n);
+	tfulldirt();
+}
+
+void
+kscrolldown(const Arg *a)
+{
+
+	int n = a->i;
+
+	if (IS_SET(MODE_ALTSCREEN))
+		return;
+
+	if (n < 0) n = (-n) * term.row;
+	if (n > TSCREEN.off) n = TSCREEN.off;
+	TSCREEN.off -= n;
+	selscroll(0, -n);
+	tfulldirt();
+}
+
+void
 tscrolldown(int orig, int n)
 {
 	int i;
@@ -1062,15 +1124,29 @@ tscrolldown(int orig, int n)
 
 	LIMIT(n, 0, term.bot-orig+1);
 
-	tsetdirt(orig, term.bot-n);
-	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
+	/* Ensure that lines are allocated */
+	for (i = -n; i < 0; i++) {
+		TLINE(i) = ensureline(TLINE(i));
+	}
 
-	for (i = term.bot; i >= orig+n; i--) {
-		temp = term.line[i];
-		term.line[i] = term.line[i-n];
-		term.line[i-n] = temp;
+	/* Shift non-scrolling areas in ring buffer */
+	for (i = term.bot+1; i < term.row; i++) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i-n);
+		TLINE(i-n) = temp;
+	}
+	for (i = 0; i < orig; i++) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i-n);
+		TLINE(i-n) = temp;
 	}
 
+	/* Scroll buffer */
+	TSCREEN.cur = (TSCREEN.cur + TSCREEN.size - n) % TSCREEN.size;
+	/* Clear lines that have entered the view */
+	tclearregion(0, orig, term.linelen-1, orig+n-1);
+	/* Redraw portion of the screen that has scrolled */
+	tsetdirt(orig+n-1, term.bot);
 	selscroll(orig, n);
 }
 
@@ -1082,15 +1158,29 @@ tscrollup(int orig, int n)
 
 	LIMIT(n, 0, term.bot-orig+1);
 
-	tclearregion(0, orig, term.col-1, orig+n-1);
-	tsetdirt(orig+n, term.bot);
+	/* Ensure that lines are allocated */
+	for (i = term.row; i < term.row + n; i++) {
+		TLINE(i) = ensureline(TLINE(i));
+	}
 
-	for (i = orig; i <= term.bot-n; i++) {
-		temp = term.line[i];
-		term.line[i] = term.line[i+n];
-		term.line[i+n] = temp;
+	/* Shift non-scrolling areas in ring buffer */
+	for (i = orig-1; i >= 0; i--) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i+n);
+		TLINE(i+n) = temp;
+	}
+	for (i = term.row-1; i >term.bot; i--) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i+n);
+		TLINE(i+n) = temp;
 	}
 
+	/* Scroll buffer */
+	TSCREEN.cur = (TSCREEN.cur + n) % TSCREEN.size;
+	/* Clear lines that have entered the view */
+	tclearregion(0, term.bot-n+1, term.linelen-1, term.bot);
+	/* Redraw portion of the screen that has scrolled */
+	tsetdirt(orig, term.bot-n+1);
 	selscroll(orig, -n);
 }
 
@@ -1194,6 +1284,7 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
 		"⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
 		"│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
 	};
+	Line line = TLINE(y);
 
 	/*
 	 * The table is proudly stolen from rxvt.
@@ -1202,25 +1293,25 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
 	   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 (line[x].mode & ATTR_WIDE) {
 		if (x+1 < term.col) {
-			term.line[y][x+1].u = ' ';
-			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
+			line[x+1].u = ' ';
+			line[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;
+	} else if (line[x].mode & ATTR_WDUMMY) {
+		line[x-1].u = ' ';
+		line[x-1].mode &= ~ATTR_WIDE;
 	}
 
 	term.dirty[y] = 1;
-	term.line[y][x] = *attr;
-	term.line[y][x].u = u;
+	line[x] = *attr;
+	line[x].u = u;
 }
 
 void
 tclearregion(int x1, int y1, int x2, int y2)
 {
-	int x, y, temp;
+	int x, y, L, S, temp;
 	Glyph *gp;
 
 	if (x1 > x2)
@@ -1228,15 +1319,16 @@ tclearregion(int x1, int y1, int x2, int y2)
 	if (y1 > y2)
 		temp = y1, y1 = y2, y2 = temp;
 
-	LIMIT(x1, 0, term.col-1);
-	LIMIT(x2, 0, term.col-1);
+	LIMIT(x1, 0, term.linelen-1);
+	LIMIT(x2, 0, term.linelen-1);
 	LIMIT(y1, 0, term.row-1);
 	LIMIT(y2, 0, term.row-1);
 
+	L = TLINEOFFSET(y1);
 	for (y = y1; y <= y2; y++) {
 		term.dirty[y] = 1;
 		for (x = x1; x <= x2; x++) {
-			gp = &term.line[y][x];
+			gp = &TSCREEN.buffer[L][x];
 			if (selected(x, y))
 				selclear();
 			gp->fg = term.c.attr.fg;
@@ -1244,6 +1336,7 @@ tclearregion(int x1, int y1, int x2, int y2)
 			gp->mode = 0;
 			gp->u = ' ';
 		}
+		L = (L + 1) % TSCREEN.size;
 	}
 }
 
@@ -1258,7 +1351,7 @@ tdeletechar(int n)
 	dst = term.c.x;
 	src = term.c.x + n;
 	size = term.col - src;
-	line = term.line[term.c.y];
+	line = TLINE(term.c.y);
 
 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
 	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
@@ -1275,7 +1368,7 @@ tinsertblank(int n)
 	dst = term.c.x + n;
 	src = term.c.x;
 	size = term.col - dst;
-	line = term.line[term.c.y];
+	line = TLINE(term.c.y);
 
 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
 	tclearregion(src, term.c.y, dst - 1, term.c.y);
@@ -2079,7 +2172,7 @@ tdumpline(int n)
 	char buf[UTF_SIZ];
 	const Glyph *bp, *end;
 
-	bp = &term.line[n][0];
+	bp = &TLINE(n)[0];
 	end = &bp[MIN(tlinelen(n), term.col) - 1];
 	if (bp != end || bp->u != ' ') {
 		for ( ; bp <= end; ++bp)
@@ -2466,11 +2559,11 @@ check_control_code:
 	if (selected(term.c.x, term.c.y))
 		selclear();
 
-	gp = &term.line[term.c.y][term.c.x];
+	gp = &TLINE(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];
+		gp = &TLINE(term.c.y)[term.c.x];
 	}
 
 	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
@@ -2483,7 +2576,7 @@ check_control_code:
 			tnewline(1);
 		else
 			tmoveto(term.col - width, term.c.y);
-		gp = &term.line[term.c.y][term.c.x];
+		gp = &TLINE(term.c.y)[term.c.x];
 	}
 
 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
@@ -2514,6 +2607,11 @@ twrite(const char *buf, int buflen, int show_ctrl)
 	Rune u;
 	int n;
 
+	if (TSCREEN.off) {
+		TSCREEN.off = 0;
+		tfulldirt();
+	}
+
 	for (n = 0; n < buflen; n += charsize) {
 		if (IS_SET(MODE_UTF8)) {
 			/* process a complete utf8 char */
@@ -2540,56 +2638,85 @@ twrite(const char *buf, int buflen, int show_ctrl)
 }
 
 void
-tresize(int col, int row)
+clearline(Line line, Glyph g, int x, int xend)
 {
 	int i;
+	g.mode = 0;
+	g.u = ' ';
+	for (i = x; i < xend; ++i) {
+		line[i] = g;
+	}
+}
+
+Line
+ensureline(Line line)
+{
+	if (!line) {
+		line = xmalloc(term.linelen * sizeof(Glyph));
+	}
+	return line;
+}
+
+void
+tresize(int col, int row)
+{
+	int i, j;
 	int minrow = MIN(row, term.row);
 	int mincol = MIN(col, term.col);
+	int linelen = MAX(col, term.linelen);
 	int *bp;
-	TCursor c;
 
-	if (col < 1 || row < 1) {
+	if (col < 1 || row < 1 || row > HISTSIZE) {
 		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]);
+	/* Shift buffer to keep the cursor where we expect it */
+	if (row <= term.c.y) {
+		term.screen[0].cur = (term.screen[0].cur - row + term.c.y + 1) % term.screen[0].size;
+	}
+
+	/* Resize and clear line buffers as needed */
+	if (linelen > term.linelen) {
+		for (i = 0; i < term.screen[0].size; ++i) {
+			if (term.screen[0].buffer[i]) {
+				term.screen[0].buffer[i] = xrealloc(term.screen[0].buffer[i], linelen * sizeof(Glyph));
+				clearline(term.screen[0].buffer[i], term.c.attr, term.linelen, linelen);
+			}
+		}
+		for (i = 0; i < minrow; ++i) {
+			term.screen[1].buffer[i] = xrealloc(term.screen[1].buffer[i], linelen * sizeof(Glyph));
+			clearline(term.screen[1].buffer[i], term.c.attr, term.linelen, linelen);
+		}
 	}
-	/* 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));
+	/* Allocate all visible lines for regular line buffer */
+	for (j = term.screen[0].cur, i = 0; i < row; ++i, j = (j + 1) % term.screen[0].size)
+	{
+		if (!term.screen[0].buffer[j]) {
+			term.screen[0].buffer[j] = xmalloc(linelen * sizeof(Glyph));
+		}
+		if (i >= term.row) {
+			clearline(term.screen[0].buffer[j], term.c.attr, 0, linelen);
+		}
 	}
-	for (i += row; i < term.row; i++) {
-		free(term.line[i]);
-		free(term.alt[i]);
+	/* Resize alt screen */
+	term.screen[1].cur = 0;
+	term.screen[1].size = row;
+	for (i = row; i < term.row; ++i) {
+		free(term.screen[1].buffer[i]);
+	}
+	term.screen[1].buffer = xrealloc(term.screen[1].buffer, row * sizeof(Line));
+	for (i = term.row; i < row; ++i) {
+		term.screen[1].buffer[i] = xmalloc(linelen * sizeof(Glyph));
+		clearline(term.screen[1].buffer[i], term.c.attr, 0, linelen);
 	}
 
 	/* resize to new height */
-	term.line = xrealloc(term.line, row * sizeof(Line));
-	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
 	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
 	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
 
-	/* resize each row to new width, zero-pad if needed */
-	for (i = 0; i < minrow; i++) {
-		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
-		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
-	}
-
-	/* allocate any new rows */
-	for (/* i = minrow */; i < row; i++) {
-		term.line[i] = xmalloc(col * sizeof(Glyph));
-		term.alt[i] = xmalloc(col * sizeof(Glyph));
-	}
+	/* fix tabstops */
 	if (col > term.col) {
 		bp = term.tabs + term.col;
 
@@ -2599,26 +2726,16 @@ tresize(int col, int row)
 		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
 			*bp = 1;
 	}
+
 	/* update terminal size */
 	term.col = col;
 	term.row = row;
+	term.linelen = linelen;
 	/* 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;
+	tfulldirt();
 }
 
 void
@@ -2630,14 +2747,15 @@ resettitle(void)
 void
 drawregion(int x1, int y1, int x2, int y2)
 {
-	int y;
+	int y, L;
 
+	L = TLINEOFFSET(y1);
 	for (y = y1; y < y2; y++) {
-		if (!term.dirty[y])
-			continue;
-
-		term.dirty[y] = 0;
-		xdrawline(term.line[y], x1, y, x2);
+		if (term.dirty[y]) {
+			term.dirty[y] = 0;
+			xdrawline(TSCREEN.buffer[L], x1, y, x2);
+		}
+		L = (L + 1) % TSCREEN.size;
 	}
 }
 
@@ -2652,14 +2770,15 @@ draw(void)
 	/* 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)
+	if (TLINE(term.ocy)[term.ocx].mode & ATTR_WDUMMY)
 		term.ocx--;
-	if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
+	if (TLINE(term.c.y)[cx].mode & ATTR_WDUMMY)
 		cx--;
 
 	drawregion(0, 0, term.col, term.row);
-	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
-			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+	if (TSCREEN.off == 0)
+		xdrawcursor(cx, term.c.y, TLINE(term.c.y)[cx],
+				term.ocx, term.ocy, TLINE(term.ocy)[term.ocx]);
 	term.ocx = cx;
 	term.ocy = term.c.y;
 	xfinishdraw();
diff --git a/st.h b/st.h
index fd3b0d8..3cea73b 100644
--- a/st.h
+++ b/st.h
@@ -19,6 +19,7 @@
 
 #define TRUECOLOR(r,g,b)	(1 << 24 | (r) << 16 | (g) << 8 | (b))
 #define IS_TRUECOL(x)		(1 << 24 & (x))
+#define HISTSIZE            2000
 
 enum glyph_attribute {
 	ATTR_NULL       = 0,
diff --git a/x.c b/x.c
index bd23686..25785a6 100644
--- a/x.c
+++ b/x.c
@@ -59,6 +59,8 @@ static void zoom(const Arg *);
 static void zoomabs(const Arg *);
 static void zoomreset(const Arg *);
 static void ttysend(const Arg *);
+void kscrollup(const Arg *);
+void kscrolldown(const Arg *);
 
 /* config.h for applying patches and the configuration. */
 #include "config.h"