add cmd option for prise.spawn

src/client.zig

@@ -181,7 +181,7 @@ pub const ClientState = struct {
     pty_validity: ?i64 = null,
 
     pub const RequestInfo = union(enum) {
-        spawn: struct { cwd: ?[]const u8 = null },
+        spawn: struct { cwd: ?[]const u8 = null, cmd: ?[]const u8 = null },
         attach: struct { pty_id: i64, cwd: ?[]const u8 = null },
         detach,
         get_server_info,
@@ -2395,7 +2395,7 @@ pub const App = struct {
         self.state.next_msgid += 1;
 
         log.info("spawnPty: sending request msgid={}", .{msgid});
-        try self.state.pending_requests.put(msgid, .{ .spawn = .{ .cwd = opts.cwd } });
+        try self.state.pending_requests.put(msgid, .{ .spawn = .{ .cwd = opts.cwd, .cmd = opts.cmd } });
 
         // Build env array from current process environment
         var env_map = try std.process.getEnvMap(self.allocator);
@@ -2409,16 +2409,23 @@ pub const App = struct {
             try env_array.append(self.allocator, .{ .string = env_str });
         }
 
-        const num_params: usize = if (opts.cwd != null) 5 else 4;
+        var num_params: usize = 4;
+        if (opts.cwd != null) num_params += 1;
+        if (opts.cmd != null) num_params += 1;
         var map_items = try self.allocator.alloc(msgpack.Value.KeyValue, num_params);
         defer self.allocator.free(map_items);
 
         map_items[0] = .{ .key = .{ .string = "rows" }, .value = .{ .unsigned = opts.rows } };
         map_items[1] = .{ .key = .{ .string = "cols" }, .value = .{ .unsigned = opts.cols } };
         map_items[2] = .{ .key = .{ .string = "attach" }, .value = .{ .boolean = opts.attach } };
         map_items[3] = .{ .key = .{ .string = "env" }, .value = .{ .array = env_array.items } };
+        var idx: usize = 4;
         if (opts.cwd) |cwd| {
-            map_items[4] = .{ .key = .{ .string = "cwd" }, .value = .{ .string = cwd } };
+            map_items[idx] = .{ .key = .{ .string = "cwd" }, .value = .{ .string = cwd } };
+            idx += 1;
+        }
+        if (opts.cmd) |cmd| {
+            map_items[idx] = .{ .key = .{ .string = "cmd" }, .value = .{ .string = cmd } };
         }
 
         const params = msgpack.Value{ .map = map_items };

src/server.zig

@@ -2056,13 +2056,14 @@ const Server = struct {
     /// Timestamp (ms since epoch) when server started - used to detect server restarts
     start_time_ms: i64 = 0,
 
-    fn parseSpawnPtyParams(params: msgpack.Value) struct { size: pty.Winsize, attach: bool, cwd: ?[]const u8, env: ?[]const msgpack.Value, macos_option_as_alt: key_encode.OptionAsAlt } {
+    fn parseSpawnPtyParams(params: msgpack.Value) struct { size: pty.Winsize, attach: bool, cwd: ?[]const u8, env: ?[]const msgpack.Value, macos_option_as_alt: key_encode.OptionAsAlt, cmd: ?[]const u8 } {
         var rows: u16 = 24;
         var cols: u16 = 80;
         var attach: bool = false;
         var cwd: ?[]const u8 = null;
         var env: ?[]const msgpack.Value = null;
         var macos_option_as_alt: key_encode.OptionAsAlt = .false;
+        var cmd: ?[]const u8 = null;
 
         if (params == .map) {
             for (params.map) |kv| {
@@ -2079,6 +2080,8 @@ const Server = struct {
                     env = kv.value.array;
                 } else if (std.mem.eql(u8, kv.key.string, "macos_option_as_alt")) {
                     macos_option_as_alt = parseMacosOptionAsAlt(kv.value);
+                } else if (std.mem.eql(u8, kv.key.string, "cmd") and kv.value == .string) {
+                    cmd = kv.value.string;
                 }
             }
         }
@@ -2094,6 +2097,7 @@ const Server = struct {
             .cwd = cwd,
             .env = env,
             .macos_option_as_alt = macos_option_as_alt,
+            .cmd = cmd,
         };
     }
 
@@ -2261,6 +2265,22 @@ const Server = struct {
             try self.sendRedraw(self.loop, pty_instance, msg, client);
         }
 
+        // Write initial command to PTY if specified
+        if (parsed.cmd) |cmd| {
+            log.info("Writing initial command to PTY {}: {s}", .{ pty_id, cmd });
+            const cmd_with_newline = try std.fmt.allocPrint(self.allocator, "{s}\n", .{cmd});
+            defer self.allocator.free(cmd_with_newline);
+
+            var total_written: usize = 0;
+            while (total_written < cmd_with_newline.len) {
+                const written = posix.write(process.master, cmd_with_newline[total_written..]) catch |err| {
+                    log.warn("Failed to write initial command to PTY {}: {}", .{ pty_id, err });
+                    break;
+                };
+                total_written += written;
+            }
+        }
+
         log.info("Created PTY {} with PID {}", .{ pty_id, process.pid });
 
         return msgpack.Value{ .unsigned = pty_id };

src/ui.zig

@@ -97,6 +97,7 @@ pub const UI = struct {
         cols: u16,
         attach: bool,
         cwd: ?[]const u8 = null,
+        cmd: ?[]const u8 = null,
     };
 
     pub const InitError = struct {
@@ -481,6 +482,10 @@ pub const UI = struct {
             if (lua.isString(-1)) opts.cwd = lua.toString(-1) catch null;
             lua.pop(1);
 
+            _ = lua.getField(1, "cmd");
+            if (lua.isString(-1)) opts.cmd = lua.toString(-1) catch null;
+            lua.pop(1);
+
             cb(ui.spawn_ctx, opts) catch |err| {
                 lua.raiseErrorStr("Failed to spawn: %s", .{@errorName(err).ptr});
             };