url-eater/README.md

# URL Eater
Clean unnecessary parameters from URLs copied to clipboard

## Usage
Run with a filter file that specifies which parameters should be removed:  
```
url-eater denylist.kdl
```
An example filter file:  
```d
category "Spotify" {
	params "context@open.spotify.com" "si@open.spotify.com"
}
category "Campaign tracking (itm)" {
	params "itm_*"
}
```
Categories do not have significance other than to make filter files better structured. 
Each parameter applies to all URLs, unless a domain like `@example.com` is specified at the end. 
Both the parameter and the domain parts can contain wildcards. Use `*` to match 0 or more characters, and `?` to match exactly one character.  
The structure is based on [NeatURL's format](https://github.com/Smile4ever/Neat-URL/#default-blocked-parameters), with a few differences (aside from a different file format):  
- Single character matching (`?`) is supported.  
- `$` and `!` rules are currently unsupported.  

The intended use case is running the program as a background service.

## Example
Before:
```
https://open.spotify.com/track/0ibuggkWTSDXHo25S0Qqvj?si=e4c675cbaee94c3a
```
After:
```
https://open.spotify.com/track/0ibuggkWTSDXHo25S0Qqvj
```

## Usage example
This repository also contains a Nix flake. It can be used in a NixOS configuration like this:  
1. Add flake to inputs:
```nix
url-eater.url = "github:AgathaSorceress/url-eater";
```
2. Add package
```nix
nixpkgs.overlays = [
  (final: prev: {
    url-eater = url-eater.defaultPackage.${final.system};
  })
];
```
3. Add a module that defines a systemd service:
```nix
{ pkgs, ... }:
let
  filters = pkgs.writeText "filters.kdl" ''
    category "Spotify" {
    	params "context@open.spotify.com" "si@open.spotify.com"
    }
    category "Twitter" {
    	params "cxt@*.twitter.com" "ref_*@*.twitter.com" "s@*.twitter.com" "t@*.twitter.com" "twclid"
    }
  '';
in {
  systemd.user.services."url-eater" = {
    description = "Clipboard URL cleanup service";

    after = [ "graphical-session-pre.target" ];
    wantedBy = [ "graphical-session.target" ];

    script = ''
      exec ${pkgs.url-eater}/bin/url-eater ${filters}
    '';
  };
}
```