authenticate and run on current virtual terminal

build.zig

@@ -111,7 +111,7 @@ fn installsystemd(self: *std.Build.Step, progress: *std.Progress.Node) !void {
     var service_dir = std.fs.openDirAbsolute("/usr/lib/systemd/system", .{}) catch unreachable;
     defer service_dir.close();
 
-    try std.fs.cwd().copyFile("res/ly.service", service_dir, "ly.service", .{ .override_mode = 644 });
+    try std.fs.cwd().copyFile("res/ly@.service", service_dir, "ly@.service", .{ .override_mode = 644 });
 }
 
 fn installopenrc(self: *std.Build.Step, progress: *std.Progress.Node) !void {

readme.md

@@ -92,9 +92,10 @@ Install Ly and the provided systemd service file
 # zig build installsystemd
 ```
 
-Enable the service
+Enable the service (this will spawn on tty2 and tty9)
 ```
-# systemctl enable ly.service
+# systemctl enable ly@tty2.service
+# systemctl enable ly@tty9.service
 ```
 
 If you need to switch between ttys after Ly's start you also have to
@@ -103,6 +104,8 @@ disable getty on Ly's tty to prevent "login" from spawning on top of it
 # systemctl disable getty@tty2.service
 ```
 
+If you have multiple ttys setup with systemd, the tty option will be used as your default tty.
+
 ### OpenRC
 **NOTE**: On Gentoo, Ly will disable the `display-manager-init` service in order to run.
 

res/ly@.service

@@ -1,17 +1,18 @@
 [Unit]
-Description=TUI display manager
+Description=TUI display manager (on %I)
 After=systemd-user-sessions.service plymouth-quit-wait.service
-After=getty@tty2.service
+After=getty@%I.service
-Conflicts=getty@tty2.service
+Conflicts=getty@%I.service
 
 [Service]
 Type=idle
 ExecStart=/usr/bin/ly
 StandardError=journal
 StandardInput=tty
-TTYPath=/dev/tty2
+TTYPath=/dev/%I
 TTYReset=yes
 TTYVHangup=yes
 
 [Install]
-Alias=display-manager.service
+WantedBy=multi-user.target
+# Alias=display-manager.service

src/interop.zig

@@ -6,6 +6,10 @@ pub const termbox = @cImport({
     @cInclude("termbox.h");
 });
 
+pub const vt = @cImport({
+    @cInclude("linux/vt.h");
+});
+
 pub const pam = @cImport({
     @cInclude("security/pam_appl.h");
 });
@@ -44,6 +48,7 @@ pub const passwd = extern struct {
     pw_shell: [*:0]u8,
 };
 
+pub const VT_GETSTATE: c_int = 0x5603;
 pub const VT_ACTIVATE: c_int = 0x5606;
 pub const VT_WAITACTIVE: c_int = 0x5607;
 

src/main.zig

@@ -526,6 +526,11 @@ pub fn main() !void {
                 defer shared_err.deinit();
 
                 {
+                    // This will set the current active VT as our TTY.
+                    var vtstat: interop.vt.vt_stat = undefined;
+                    _ = std.c.ioctl(std.c.STDIN_FILENO, interop.VT_GETSTATE, &vtstat);
+                    config.tty = @intCast(vtstat.v_active);
+
                     const login_text = try allocator.dupeZ(u8, login.text.items);
                     defer allocator.free(login_text);
                     const password_text = try allocator.dupeZ(u8, password.text.items);