Update TODO.md

TODO.md

@@ -1,4 +1,5 @@
 Add swayidle to make the screen go dark
+And add adrien user to uinput
 
 ---
 
@@ -106,4 +107,95 @@ Log out of your niri session and log back in. The `idle.sh` script will now be r
 *   **Customizing swaylock:**
     You can make `swaylock` look nicer. For example, to set a solid color:
     `swaylock -f -c 000000` (for black).
-    You can edit this command directly in your `idle.sh` script. Check `man swaylock` for all options.
+    You can edit this command directly in your `idle.sh` script. Check `man swaylock` for all options.
+
+---
+
+Of course! Let's break down what `uinput` is, why you're getting a "permission denied" error, and exactly how to fix it on your Arch Linux system.
+
+### What is `uinput`? (The Simple Explanation)
+
+Think of `uinput` (User Input) as a special module in the Linux kernel. Its job is to let a regular program **pretend to be a physical input device**.
+
+When you move your real mouse, the hardware sends a signal to the kernel, and the kernel tells your desktop environment, "The mouse just moved to coordinates X, Y."
+
+`uinput` allows a program, like Sunshine, to do the exact same thing, but in software. Sunshine can tell the `uinput` module, "Hey, pretend a mouse just moved to coordinates X, Y," and the kernel will treat it exactly as if a real mouse did it.
+
+This is essential for applications like:
+*   **Sunshine/Moonlight:** To inject mouse, keyboard, and gamepad inputs coming from your client device over the network.
+*   **Steam:** For the Steam Input feature, which can make a controller look like a keyboard and mouse to a game.
+*   **Input Remappers:** Tools that change what your keyboard keys or controller buttons do.
+
+### The Permission Problem
+
+For security reasons, you don't want just *any* application to be able to create fake keyboard presses or mouse movements. If any program could do this, it would be trivial to create a keylogger or malware that could take control of your computer.
+
+Because this is a powerful and potentially dangerous feature, Linux protects it with file permissions. The `uinput` functionality is exposed through a special device file: `/dev/uinput`.
+
+Let's look at the permissions on that file. If you run this command in your terminal:
+
+```bash
+ls -l /dev/uinput
+```
+
+You will likely see something like this:
+
+```
+crw-rw---- 1 root uinput 10, 223 Dec 15 10:30 /dev/uinput
+```
+
+Let's break that down:
+*   `c`: It's a character device file.
+*   `rw-`: The **owner** (`root`) has read and write permissions.
+*   `rw-`: The **group** (`uinput`) has read and write permissions.
+*   `---`: **Everyone else** has no permissions at all.
+
+When you run Sunshine, it runs as *your* user account (e.g., `myuser`), not as `root`. By default, your user is not in the `uinput` group. Therefore, when Sunshine tries to access `/dev/uinput` to create a virtual mouse or keyboard, the kernel sees that your user is in the "everyone else" category and says **"Permission Denied"**.
+
+### The Solution: The `uinput` Group
+
+The forum's advice is exactly correct. The `uinput` group was created specifically for this purpose: to grant trusted users the ability to access the `uinput` device without giving them full `root` privileges.
+
+By adding your user to the `uinput` group, you are telling the system, "I trust this user account to run programs (like Sunshine) that need to create virtual input devices."
+
+---
+
+### How to Fix It: Step-by-Step
+
+Here are the commands to solve your problem on Arch Linux.
+
+**1. Add Your User to the `uinput` Group**
+
+Open a terminal and run the following command. Make sure to replace `your_username` with your actual username. If you're not sure, you can run the command `whoami` to see it.
+
+```bash
+sudo gpasswd -a your_username uinput
+```
+*   `sudo`: Run this command with administrator privileges.
+*   `gpasswd`: A command to manage group memberships.
+*   `-a your_username`: The action is to **a**dd the specified user.
+*   `uinput`: The group you are adding the user to.
+
+**2. Apply the Changes**
+
+Group membership changes only take effect when you start a new login session. The current session you are in will not have the new permissions. You have two options:
+
+*   **Log Out and Log Back In:** This is the cleanest and most recommended way. Log out of your Niri session completely and then log back in.
+*   **Reboot:** A full reboot will also work.
+
+**3. Verify the Change (Optional)**
+
+After you have logged back in, you can verify that you are now a member of the group by running:
+
+```bash
+groups
+```
+
+You should see `uinput` listed in the output, along with your other groups.
+
+```
+# Example output
+wheel audio video input uinput myuser
+```
+
+Once you've done this, Sunshine should have the necessary permissions to create virtual input devices, and your mouse, keyboard, and controller should start working correctly on your Niri desktop