terminal: boilerplate for tmux control mode parsing

src/terminal/dcs.zig

@@ -98,6 +98,8 @@ pub const Handler = struct {
             .ignore,
             => {},
 
+            .tmux => {},
+
             .xtgettcap => |*list| {
                 if (list.items.len >= self.max_bytes) {
                     return error.OutOfMemory;
@@ -126,6 +128,8 @@ pub const Handler = struct {
             .ignore,
             => null,
 
+            .tmux => null,
+
             .xtgettcap => |list| .{ .xtgettcap = .{ .data = list } },
 
             .decrqss => |buffer| .{ .decrqss = switch (buffer.len) {
@@ -157,6 +161,8 @@ pub const Handler = struct {
             .xtgettcap => |*list| list.deinit(),
 
             .decrqss => {},
+
+            .tmux => {},
         }
 
         self.state = .{ .inactive = {} };
@@ -170,10 +176,14 @@ pub const Command = union(enum) {
     /// DECRQSS
     decrqss: DECRQSS,
 
+    /// Tmux control mode
+    tmux: Tmux,
+
     pub fn deinit(self: Command) void {
         switch (self) {
             .xtgettcap => |*v| v.data.deinit(),
             .decrqss => {},
+            .tmux => {},
         }
     }
 
@@ -207,6 +217,12 @@ pub const Command = union(enum) {
         decstbm,
         decslrm,
     };
+
+    /// Tmux control mode
+    pub const Tmux = union(enum) {
+        enter: void,
+        exit: void,
+    };
 };
 
 const State = union(enum) {
@@ -225,6 +241,9 @@ const State = union(enum) {
         data: [2]u8 = undefined,
         len: u2 = 0,
     },
+
+    /// Tmux control mode: https://github.com/tmux/tmux/wiki/Control-Mode
+    tmux: void,
 };
 
 test "unknown DCS command" {

src/termio/Exec.zig

@@ -1880,6 +1880,11 @@ const StreamHandler = struct {
     fn dcsCommand(self: *StreamHandler, cmd: *terminal.dcs.Command) !void {
         // log.warn("DCS command: {}", .{cmd});
         switch (cmd.*) {
+            .tmux => |tmux| {
+                // TODO: process it
+                log.warn("tmux control mode event unimplemented cmd={}", .{tmux});
+            },
+
             .xtgettcap => |*gettcap| {
                 const map = comptime terminfo.ghostty.xtgettcapMap();
                 while (gettcap.next()) |key| {
@@ -1887,6 +1892,7 @@ const StreamHandler = struct {
                     self.messageWriter(.{ .write_stable = response });
                 }
             },
+
             .decrqss => |decrqss| {
                 var response: [128]u8 = undefined;
                 var stream = std.io.fixedBufferStream(&response);