Merge pull request #646 from mitchellh/sm

xterm audit: DECALN, Top/Bot Margins, Left/Right Margins

src/terminal/Terminal.zig

@@ -866,16 +866,37 @@ pub fn decaln(self: *Terminal) !void {
     defer tracy.end();
 
     // Reset margins, also sets cursor to top-left
-    self.setScrollingRegion(0, 0);
+    self.scrolling_region = .{
+        .top = 0,
+        .bottom = self.rows - 1,
+        .left = 0,
+        .right = self.cols - 1,
+    };
 
-    // Fill with Es, does not move cursor. We reset fg/bg so we can just
+    // Origin mode is disabled
-    // optimize here by doing row copies.
+    self.modes.set(.origin, false);
-    const filled = self.screen.getRow(.{ .active = 0 });
-    filled.fill(.{ .char = 'E' });
 
-    var row: usize = 1;
+    // Move our cursor to the top-left
-    while (row < self.rows) : (row += 1) {
+    self.setCursorPos(1, 1);
-        try self.screen.getRow(.{ .active = row }).copyRow(filled);
+
+    // Clear our stylistic attributes
+    self.screen.cursor.pen = .{
+        .bg = self.screen.cursor.pen.bg,
+        .fg = self.screen.cursor.pen.fg,
+        .attrs = .{
+            .has_bg = self.screen.cursor.pen.attrs.has_bg,
+            .has_fg = self.screen.cursor.pen.attrs.has_fg,
+            .protected = self.screen.cursor.pen.attrs.protected,
+        },
+    };
+
+    // Our pen has the letter E
+    var pen: Screen.Cell = .{ .char = 'E' };
+
+    // Fill with Es, does not move cursor.
+    for (0..self.rows) |y| {
+        const filled = self.screen.getRow(.{ .active = y });
+        filled.fill(pen);
     }
 }
 
@@ -1767,19 +1788,33 @@ pub fn scrollViewport(self: *Terminal, behavior: ScrollViewport) !void {
 /// and bottom-most line of the screen.
 ///
 /// Top and bottom are 1-indexed.
-pub fn setScrollingRegion(self: *Terminal, top: usize, bottom: usize) void {
+pub fn setTopAndBottomMargin(self: *Terminal, top_req: usize, bottom_req: usize) void {
     const tracy = trace(@src());
     defer tracy.end();
 
-    var t = if (top == 0) 1 else top;
+    const top = @max(1, top_req);
-    var b = @min(bottom, self.rows);
+    const bottom = @min(self.rows, if (bottom_req == 0) self.rows else bottom_req);
-    if (t >= b) {
+    if (top >= bottom) return;
-        t = 1;
-        b = self.rows;
-    }
 
-    self.scrolling_region.top = t - 1;
+    self.scrolling_region.top = top - 1;
-    self.scrolling_region.bottom = b - 1;
+    self.scrolling_region.bottom = bottom - 1;
+    self.setCursorPos(1, 1);
+}
+
+/// DECSLRM
+pub fn setLeftAndRightMargin(self: *Terminal, left_req: usize, right_req: usize) void {
+    const tracy = trace(@src());
+    defer tracy.end();
+
+    // We must have this mode enabled to do anything
+    if (!self.modes.get(.enable_left_and_right_margin)) return;
+
+    const left = @max(1, left_req);
+    const right = @min(self.rows, if (right_req == 0) self.rows else right_req);
+    if (left >= right) return;
+
+    self.scrolling_region.left = left - 1;
+    self.scrolling_region.right = right - 1;
     self.setCursorPos(1, 1);
 }
 
@@ -2513,7 +2548,7 @@ test "Terminal: setCursorPos (original test)" {
     try testing.expectEqual(@as(usize, 79), t.screen.cursor.y);
 
     // Set the scroll region
-    t.setScrollingRegion(10, t.rows);
+    t.setTopAndBottomMargin(10, t.rows);
     t.setCursorPos(0, 0);
     try testing.expectEqual(@as(usize, 0), t.screen.cursor.x);
     try testing.expectEqual(@as(usize, 9), t.screen.cursor.y);
@@ -2526,41 +2561,217 @@ test "Terminal: setCursorPos (original test)" {
     try testing.expectEqual(@as(usize, 0), t.screen.cursor.x);
     try testing.expectEqual(@as(usize, 79), t.screen.cursor.y);
 
-    t.setScrollingRegion(10, 11);
+    t.setTopAndBottomMargin(10, 11);
     t.setCursorPos(2, 0);
     try testing.expectEqual(@as(usize, 0), t.screen.cursor.x);
     try testing.expectEqual(@as(usize, 10), t.screen.cursor.y);
 }
 
-test "Terminal: setScrollingRegion" {
+test "Terminal: setTopAndBottomMargin simple" {
-    var t = try init(testing.allocator, 80, 80);
+    const alloc = testing.allocator;
-    defer t.deinit(testing.allocator);
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
 
-    // Initial value
+    try t.printString("ABC");
-    try testing.expectEqual(@as(usize, 0), t.scrolling_region.top);
+    t.carriageReturn();
-    try testing.expectEqual(@as(usize, t.rows - 1), t.scrolling_region.bottom);
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.setTopAndBottomMargin(0, 0);
+    try t.scrollDown(1);
 
-    // Move our cusor so we can verify we move it back
+    {
-    t.setCursorPos(5, 5);
+        var str = try t.plainString(testing.allocator);
-    t.setScrollingRegion(3, 7);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("\nABC\nDEF\nGHI", str);
+    }
+}
 
-    // Cursor should move back to top-left
+test "Terminal: setTopAndBottomMargin top only" {
-    try testing.expectEqual(@as(usize, 0), t.screen.cursor.x);
+    const alloc = testing.allocator;
-    try testing.expectEqual(@as(usize, 0), t.screen.cursor.y);
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
 
-    // Scroll region is set
+    try t.printString("ABC");
-    try testing.expectEqual(@as(usize, 2), t.scrolling_region.top);
+    t.carriageReturn();
-    try testing.expectEqual(@as(usize, 6), t.scrolling_region.bottom);
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.setTopAndBottomMargin(2, 0);
+    try t.scrollDown(1);
 
-    // Scroll region invalid
+    {
-    t.setScrollingRegion(7, 3);
+        var str = try t.plainString(testing.allocator);
-    try testing.expectEqual(@as(usize, 0), t.scrolling_region.top);
+        defer testing.allocator.free(str);
-    try testing.expectEqual(@as(usize, t.rows - 1), t.scrolling_region.bottom);
+        try testing.expectEqualStrings("ABC\n\nDEF\nGHI", str);
+    }
+}
 
-    // Scroll region with zero top and bottom
+test "Terminal: setTopAndBottomMargin top and bottom" {
-    t.setScrollingRegion(0, 0);
+    const alloc = testing.allocator;
-    try testing.expectEqual(@as(usize, 0), t.scrolling_region.top);
+    var t = try init(alloc, 5, 5);
-    try testing.expectEqual(@as(usize, t.rows - 1), t.scrolling_region.bottom);
+    defer t.deinit(alloc);
+
+    try t.printString("ABC");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.setTopAndBottomMargin(1, 2);
+    try t.scrollDown(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("\nABC\nGHI", str);
+    }
+}
+
+test "Terminal: setTopAndBottomMargin top equal to bottom" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    try t.printString("ABC");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.setTopAndBottomMargin(2, 2);
+    try t.scrollDown(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("\nABC\nDEF\nGHI", str);
+    }
+}
+
+test "Terminal: setLeftAndRightMargin simple" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    try t.printString("ABC");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.modes.set(.enable_left_and_right_margin, true);
+    t.setLeftAndRightMargin(0, 0);
+    t.eraseChars(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings(" BC\nDEF\nGHI", str);
+    }
+}
+
+test "Terminal: setLeftAndRightMargin left only" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    try t.printString("ABC");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.modes.set(.enable_left_and_right_margin, true);
+    t.setLeftAndRightMargin(2, 0);
+    t.setCursorPos(1, 2);
+    try t.insertLines(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("A\nDBC\nGEF\n HI", str);
+    }
+}
+
+test "Terminal: setLeftAndRightMargin left and right" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    try t.printString("ABC");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.modes.set(.enable_left_and_right_margin, true);
+    t.setLeftAndRightMargin(1, 2);
+    t.setCursorPos(1, 2);
+    try t.insertLines(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("  C\nABF\nDEI\nGH", str);
+    }
+}
+
+test "Terminal: setLeftAndRightMargin left equal right" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    try t.printString("ABC");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.modes.set(.enable_left_and_right_margin, true);
+    t.setLeftAndRightMargin(2, 2);
+    t.setCursorPos(1, 2);
+    try t.insertLines(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("\nABC\nDEF\nGHI", str);
+    }
+}
+
+test "Terminal: setLeftAndRightMargin mode 69 unset" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 5, 5);
+    defer t.deinit(alloc);
+
+    try t.printString("ABC");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("DEF");
+    t.carriageReturn();
+    try t.linefeed();
+    try t.printString("GHI");
+    t.modes.set(.enable_left_and_right_margin, false);
+    t.setLeftAndRightMargin(1, 2);
+    t.setCursorPos(1, 2);
+    try t.insertLines(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("\nABC\nDEF\nGHI", str);
+    }
 }
 
 test "Terminal: deleteLines" {
@@ -2615,7 +2826,7 @@ test "Terminal: deleteLines with scroll region" {
     try t.linefeed();
     try t.print('D');
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.setCursorPos(1, 1);
     try t.deleteLines(1);
 
@@ -2651,7 +2862,7 @@ test "Terminal: deleteLines with scroll region, large count" {
     try t.linefeed();
     try t.print('D');
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.setCursorPos(1, 1);
     try t.deleteLines(5);
 
@@ -2687,7 +2898,7 @@ test "Terminal: deleteLines with scroll region, cursor outside of region" {
     try t.linefeed();
     try t.print('D');
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.setCursorPos(4, 1);
     try t.deleteLines(1);
 
@@ -2820,7 +3031,7 @@ test "Terminal: insertLines outside of scroll region" {
     t.carriageReturn();
     try t.linefeed();
     try t.printString("GHI");
-    t.setScrollingRegion(3, 4);
+    t.setTopAndBottomMargin(3, 4);
     t.setCursorPos(2, 2);
     try t.insertLines(1);
 
@@ -2846,7 +3057,7 @@ test "Terminal: insertLines top/bottom scroll region" {
     t.carriageReturn();
     try t.linefeed();
     try t.printString("123");
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.setCursorPos(2, 2);
     try t.insertLines(1);
 
@@ -2944,7 +3155,7 @@ test "Terminal: insertLines with scroll region" {
     try t.linefeed();
     try t.print('E');
 
-    t.setScrollingRegion(1, 2);
+    t.setTopAndBottomMargin(1, 2);
     t.setCursorPos(1, 1);
     try t.insertLines(1);
 
@@ -3089,7 +3300,7 @@ test "Terminal: reverseIndex top of scrolling region" {
     try t.linefeed();
 
     // Set our scroll region
-    t.setScrollingRegion(2, 5);
+    t.setTopAndBottomMargin(2, 5);
     t.setCursorPos(2, 1);
     try t.reverseIndex();
     try t.print('X');
@@ -3141,7 +3352,7 @@ test "Terminal: index outside of scrolling region" {
     defer t.deinit(alloc);
 
     try testing.expectEqual(@as(usize, 0), t.screen.cursor.y);
-    t.setScrollingRegion(2, 5);
+    t.setTopAndBottomMargin(2, 5);
     try t.index();
     try testing.expectEqual(@as(usize, 1), t.screen.cursor.y);
 }
@@ -3151,7 +3362,7 @@ test "Terminal: index from the bottom outside of scroll region" {
     var t = try init(alloc, 2, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 2);
+    t.setTopAndBottomMargin(1, 2);
     t.setCursorPos(5, 1);
     try t.print('A');
     try t.index();
@@ -3228,7 +3439,7 @@ test "Terminal: index inside scroll region" {
     var t = try init(alloc, 5, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     try t.print('A');
     try t.index();
     try t.print('X');
@@ -3245,7 +3456,7 @@ test "Terminal: index bottom of scroll region" {
     var t = try init(alloc, 5, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.setCursorPos(4, 1);
     try t.print('B');
     t.setCursorPos(3, 1);
@@ -3265,7 +3476,7 @@ test "Terminal: index bottom of primary screen with scroll region" {
     var t = try init(alloc, 5, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.setCursorPos(3, 1);
     try t.print('A');
     t.setCursorPos(5, 1);
@@ -3286,7 +3497,7 @@ test "Terminal: index outside left/right margin" {
     var t = try init(alloc, 10, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.scrolling_region.left = 3;
     t.scrolling_region.right = 5;
     t.setCursorPos(3, 3);
@@ -3307,7 +3518,7 @@ test "Terminal: index inside left/right margin" {
     var t = try init(alloc, 10, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     t.scrolling_region.left = 3;
     t.scrolling_region.right = 5;
     t.setCursorPos(3, 3);
@@ -3344,6 +3555,50 @@ test "Terminal: DECALN" {
     }
 }
 
+test "Terminal: decaln reset margins" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 3, 3);
+    defer t.deinit(alloc);
+
+    // Initial value
+    t.modes.set(.origin, true);
+    t.setTopAndBottomMargin(2, 3);
+    try t.decaln();
+    try t.scrollDown(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("\nEEE\nEEE", str);
+    }
+}
+
+test "Terminal: decaln preserves color" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 3, 3);
+    defer t.deinit(alloc);
+
+    const pen: Screen.Cell = .{
+        .bg = .{ .r = 0xFF, .g = 0x00, .b = 0x00 },
+        .attrs = .{ .has_bg = true },
+    };
+
+    // Initial value
+    t.screen.cursor.pen = pen;
+    t.modes.set(.origin, true);
+    t.setTopAndBottomMargin(2, 3);
+    try t.decaln();
+    try t.scrollDown(1);
+
+    {
+        var str = try t.plainString(testing.allocator);
+        defer testing.allocator.free(str);
+        try testing.expectEqualStrings("\nEEE\nEEE", str);
+        const cell = t.screen.getCell(.active, 0, 0);
+        try testing.expectEqual(pen, cell);
+    }
+}
+
 test "Terminal: insertBlanks" {
     // NOTE: this is not verified with conformance tests, so these
     // tests might actually be verifying wrong behavior.
@@ -5181,7 +5436,7 @@ test "Terminal: cursorDown above bottom scroll margin" {
     var t = try init(alloc, 5, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     try t.print('A');
     t.cursorDown(10);
     try t.print('X');
@@ -5198,7 +5453,7 @@ test "Terminal: cursorDown below bottom scroll margin" {
     var t = try init(alloc, 5, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(1, 3);
+    t.setTopAndBottomMargin(1, 3);
     try t.print('A');
     t.setCursorPos(4, 1);
     t.cursorDown(10);
@@ -5251,7 +5506,7 @@ test "Terminal: cursorUp below top scroll margin" {
     var t = try init(alloc, 5, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(2, 4);
+    t.setTopAndBottomMargin(2, 4);
     t.setCursorPos(3, 1);
     try t.print('A');
     t.cursorUp(5);
@@ -5269,7 +5524,7 @@ test "Terminal: cursorUp above top scroll margin" {
     var t = try init(alloc, 5, 5);
     defer t.deinit(alloc);
 
-    t.setScrollingRegion(3, 5);
+    t.setTopAndBottomMargin(3, 5);
     t.setCursorPos(3, 1);
     try t.print('A');
     t.setCursorPos(2, 1);
@@ -5403,7 +5658,7 @@ test "Terminal: scrollDown outside of scroll region" {
     t.carriageReturn();
     try t.linefeed();
     try t.printString("GHI");
-    t.setScrollingRegion(3, 4);
+    t.setTopAndBottomMargin(3, 4);
     t.setCursorPos(2, 2);
     const cursor = t.screen.cursor;
     try t.scrollDown(1);

src/terminal/modes.zig

@@ -134,10 +134,12 @@ const ModeTag = packed struct(u16) {
 
 pub fn modeFromInt(v: u16, ansi: bool) ?Mode {
     inline for (entries) |entry| {
-        if (entry.value == v and entry.ansi == ansi) {
+        if (comptime !entry.disabled) {
-            const tag: ModeTag = .{ .ansi = ansi, .value = entry.value };
+            if (entry.value == v and entry.ansi == ansi) {
-            const int: ModeTag.Backing = @bitCast(tag);
+                const tag: ModeTag = .{ .ansi = ansi, .value = entry.value };
-            return @enumFromInt(int);
+                const int: ModeTag.Backing = @bitCast(tag);
+                return @enumFromInt(int);
+            }
         }
     }
 
@@ -160,6 +162,7 @@ const ModeEntry = struct {
     value: comptime_int,
     default: bool = false,
     ansi: bool = false,
+    disabled: bool = false,
 };
 
 /// The full list of available entries. For documentation see how
@@ -195,6 +198,10 @@ const entries: []const ModeEntry = &.{
     .{ .name = "bracketed_paste", .value = 2004 },
     .{ .name = "synchronized_output", .value = 2026 },
     .{ .name = "grapheme_cluster", .value = 2027 },
+
+    // Disabled for now until we ensure we get left/right margins working
+    // correctly in all sequences.
+    .{ .name = "enable_left_and_right_margin", .value = 69, .disabled = true },
 };
 
 test {

src/terminal/stream.zig

@@ -787,8 +787,20 @@ pub fn Stream(comptime Handler: type) type {
                     ),
                 },
 
-                // Save Mode
                 's' => switch (action.intermediates.len) {
+                    // DECSLRM
+                    0 => if (@hasDecl(T, "setLeftAndRightMargin")) {
+                        switch (action.params.len) {
+                            0 => try self.handler.setLeftAndRightMargin(0, 0),
+                            1 => try self.handler.setLeftAndRightMargin(action.params[0], 0),
+                            2 => try self.handler.setLeftAndRightMargin(action.params[0], action.params[1]),
+                            else => log.warn("invalid DECSLRM command: {}", .{action}),
+                        }
+                    } else log.warn(
+                        "unimplemented CSI callback: {}",
+                        .{action},
+                    ),
+
                     1 => switch (action.intermediates[0]) {
                         '?' => if (@hasDecl(T, "saveMode")) {
                             for (action.params) |mode_int| {

src/termio/Exec.zig

@@ -1394,7 +1394,11 @@ const StreamHandler = struct {
     }
 
     pub fn setTopAndBottomMargin(self: *StreamHandler, top: u16, bot: u16) !void {
-        self.terminal.setScrollingRegion(top, bot);
+        self.terminal.setTopAndBottomMargin(top, bot);
+    }
+
+    pub fn setLeftAndRightMargin(self: *StreamHandler, left: u16, right: u16) !void {
+        self.terminal.setLeftAndRightMargin(left, right);
     }
 
     pub fn setModifyKeyFormat(self: *StreamHandler, format: terminal.ModifyKeyFormat) !void {
@@ -1460,6 +1464,13 @@ const StreamHandler = struct {
             // Origin resets cursor pos
             .origin => self.terminal.setCursorPos(1, 1),
 
+            .enable_left_and_right_margin => if (!enabled) {
+                // When we disable left/right margin mode we need to
+                // reset the left/right margins.
+                self.terminal.scrolling_region.left = 0;
+                self.terminal.scrolling_region.right = self.terminal.cols - 1;
+            },
+
             .alt_screen_save_cursor_clear_enter => {
                 const opts: terminal.Terminal.AlternateScreenOptions = .{
                     .cursor_save = true,

website/app/vt/decaln/page.mdx

@@ -0,0 +1,45 @@
+import VTSequence from "@/components/VTSequence";
+
+# Screen Alignment Test (DECALN)
+
+<VTSequence sequence={["ESC", "#", "8"]} />
+
+Reset margins, move cursor to the top left, and fill the screen with `E`.
+
+Reset the top, bottom, left, and right margins and unset [origin mode](#TODO).
+The cursor is moved to the top-left corner of the screen.
+
+All stylistic SGR attributes are unset, such as bold, blink, etc.
+SGR foreground and background colors are preserved.
+The [protected attribute](#TODO) is not unset.
+
+The entire screen is filled with the character `E`. The letter `E` ignores
+the current SGR settings and is written with no styling.
+
+## Validation
+
+### DECALN V-1: Simple Usage
+
+```bash
+printf "\033#8"
+```
+
+```
+|EEEEEEEE|
+|EEEEEEEE|
+|EEEEEEEE|
+```
+
+### DECALN V-2: Reset Margins
+
+```bash
+printf "\033[2;3r" # scroll region top/bottom
+printf "\033#8"
+printf "\033[T"
+```
+
+```
+|c_______|
+|EEEEEEEE|
+|EEEEEEEE|
+```

website/app/vt/decslrm/page.mdx

@@ -0,0 +1,120 @@
+import VTSequence from "@/components/VTSequence";
+
+# Set Left and Right Margins (DECSLRM)
+
+<VTSequence sequence={["CSI", "Pl", ";", "Pr", "s"]} />
+
+Sets the left and right margins, otherwise known as the scroll region.
+To learn more about scroll regions in general, see
+[Set Top and Bottom Margins](/vt/decstbm).
+
+Parameters `l` and `r` are integer values. If either value is zero the
+value will be reset to default values. The default value for `l` is `1`
+and the default value of `r` is the number of columns in the screen.
+
+Values `l` and `r` can be omitted. If either value is omitted, their
+default values will be used. Note that it is impossible to omit `l`
+and not omit `r`.
+
+This sequence requires [enable left and right margin (mode 69)](#TODO)
+to be set. If mode 69 is not set, this sequence does nothing and left
+and right margins will not be set.
+
+This sequence conflicts with [save cursor (`CSI s`)](#TODO). If
+mode 69 is disabled, save cursor will be invoked. If mode 69 is enabled,
+the `CSI s` save cursor sequence will be disabled, but save cursor is always
+also available as `ESC 7`.
+
+If left is larger or equal to right, this sequence does nothing. A
+scroll region must be at least two columns (`r` must be greater than `l`).
+The rest of this sequence description assumes valid values for `l` and `r`.
+
+This sequence unsets the pending wrap state and moves the cursor to
+the top-left of the screen. If [origin mode](#TODO) is set, the cursor is
+moved to the top-left of the scroll region.
+
+To reset the left and right margins, call this sequence with both values set to
+"0". This will force the default values for both `l` and `r` which is
+the full screen. Unsetting mode 69 will also reset the left and right margins.
+
+## Validation
+
+### DECSLRM V-1: Full Screen
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[?69h" # enable left/right margins
+printf "\033[s" # scroll region left/right
+printf "\033[X"
+```
+
+```
+|cBC_____|
+|DEF_____|
+|GHI_____|
+```
+
+### DECSLRM V-2: Left Only
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[?69h" # enable left/right margins
+printf "\033[2s" # scroll region left/right
+printf "\033[2G" # move cursor to column 2
+printf "\033[L"
+```
+
+```
+|Ac______|
+|DBC_____|
+|GEF_____|
+| HI_____|
+```
+
+### DECSLRM V-3: Left And Right
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[?69h" # enable left/right margins
+printf "\033[1;2s" # scroll region left/right
+printf "\033[2G" # move cursor to column 2
+printf "\033[L"
+```
+
+```
+|_cC_____|
+|ABF_____|
+|DEI_____|
+|GH______|
+```
+
+### DECSLRM V-4: Left Equal to Right
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[?69h" # enable left/right margins
+printf "\033[2;2s" # scroll region left/right
+printf "\033[X"
+```
+
+```
+|cBC_____|
+|DEF_____|
+|GHI_____|
+```

website/app/vt/decstbm/page.mdx

@@ -0,0 +1,111 @@
+import VTSequence from "@/components/VTSequence";
+
+# Set Top and Bottom Margins (DECSTBM)
+
+<VTSequence sequence={["CSI", "Pt", ";", "Pb", "r"]} />
+
+Sets the top and bottom margins, otherwise known as the scroll region.
+
+Parameters `t` and `b` are integer values. If either value is zero the
+value will be reset to default values. The default value for `t` is `1`
+and the default value of `b` is the number of rows in the screen.
+
+Values `t` and `b` can be omitted. If either value is omitted, their
+default values will be used. Note that it is impossible to omit `t`
+and not omit `b`. The only valid sequences are `CSI t ; b r`,
+`CSI t r` and `CSI r`.
+
+If top is larger or equal to bottom, this sequence does nothing. A
+scroll region must be at least two rows (`b` must be greater than `t`).
+The rest of this sequence description assumes valid values for `t` and `b`.
+
+This sequence unsets the pending wrap state and moves the cursor to
+the top-left of the screen. If [origin mode](#TODO) is set, the cursor is
+moved to the top-left of the scroll region.
+
+To reset the scroll region, call this sequence with both values set to
+"0". This will force the default values for both `t` and `b` which is
+the full screen.
+
+The top and bottom margin constitute what is known as the _scroll region_.
+The scroll region impacts the operation of many sequences such as
+[insert line](/vt/il), [cursor down](/vt/cud), etc. Scroll regions are
+an effective and efficient way to constraint terminal modifications to a
+rectangular region of the screen.
+
+## Validation
+
+### DECSTBM V-1: Full Screen
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[r" # scroll region top/bottom
+printf "\033[T"
+```
+
+```
+|c_______|
+|ABC_____|
+|DEF_____|
+|GHI_____|
+```
+
+### DECSTBM V-2: Top Only
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[2r" # scroll region top/bottom
+printf "\033[T"
+```
+
+```
+|ABC_____|
+|________|
+|DEF_____|
+|GHI_____|
+```
+
+### DECSTBM V-3: Top and Bottom
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[1;2r" # scroll region top/bottom
+printf "\033[T"
+```
+
+```
+|________|
+|ABC_____|
+|GHI_____|
+```
+
+### DECSTBM V-4: Top Equal to Bottom
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "ABC\n"
+printf "DEF\n"
+printf "GHI\n"
+printf "\033[2;2r" # scroll region top/bottom
+printf "\033[T"
+```
+
+```
+|________|
+|ABC_____|
+|DEF_____|
+|GHI_____|
+```