How do I Make two seperate program configs and build both of them in the same nix config?

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1

I’m using Home Manager and hyprland and I’ve decided that I want a button that will switch between two different hyprconfigs, I know this works for hyprland instantly without the need for rebuilding as long as you have those configs, but I don’t know how to make both of them declaratively.

one is easy enough especially with home manager, and I can see how to do two if I knew how to make a new general file in nixos declaratively, but idk how to do that.

also, if possible it would be nice to do both within my hyprland home manager config, but I can live without that if needed.

2

I do not know the config about hyprland, but I have some general ideas.
Maybe declare both config files in different name, i.e. hyprconfigA, hyprconfigB in home manager
And you manually make a script to symlink either of them when you run it, like ln -s /home/user/.config/someprogram/hyprconfigA /home/user/.config/someprogram/hyprconfig, something like that.

maybe there are some better way for this.

3

You can try using wrappers.

4

that is what I want, and I know how to do the command bit, but what I don’t know is how to build two separate configs at once. any ideas?

5

looking at the link, this would create a separate config for every user, but not a different config. though I would assume such a thing should be possible. I’ll look into it and try to find some better documentation.

thanks for the advice.

6

(Yes, that’s possible. Sorry, I’m not good at English, so I’ll try to explain using code instead.)

{ pkgs, ... }:
let
  # Create configuration files in the Nix store
  config-1 = pkgs.writeText "hyprland-config-1.conf" ''
    ...
  '';
  config-2 = pkgs.writeText "hyprland-config-2.conf" ''
    ...
  '';
  # or read existing files
  config-1 = ./hyprland-config-1.conf;
  config-2 = ./hyprland-config-2.conf;

  # Create shell scripts in the Nix store
  hyprland-session-config-1 = pkgs.writeScriptBin "hyprland-session-config-1" ''
    #! ${pkgs.bash}/bin/bash
    exec ${pkgs.hyprland}/bin/hyprland -c ${config-1}
  '';
  hyprland-session-config-2 = pkgs.writeScriptBin "hyprland-session-config-1" ''
    #! ${pkgs.bash}/bin/bash
    exec ${pkgs.hyprland}/bin/hyprland -c ${config-2}
  '';
in
{
  # Then add these shell scripts to the environment.
  environment.systemPackages = [
    hyprland-session-config-1
    hyprland-session-config-2
  ];
  # also can be added to users' environment.
  users.users."userName".packages = [
    hyprland-session-config-1
    hyprland-session-config-2
  ];
}

Then run them in bash.

hyprland-session-config-1
# or
hyprland-session-config-2

Also see Nix-writers and wrapper-manager.

7

this is really close to what I want, but sadly it doesn’t quite work, it doesn’t change hyprland’s config, it opens a new instance of hyprland with that config.

I’m trying to find out how to get hyprland to use a preset config, but the only solution I’m seeing so far is copy/pasting a config into the hyprconfig folder and renaming it which doesn’t work because nixos, symlinks and read-only file systems.

thank you for your help though. this approach would work if it werent for how hyprland worked.

8

But this is also easy enough with nix right? don’t have nix create the config file. Have it create two files in the store, and then make a script does the (re)linking in the config directory.

i.e.

config1 = pkgs.writeText "config1" "...";
config2 = pkgs.writeText "config2" "...";
switcher = pkgs.writeShellScriptBin "switch" ''
  config=~/.config/hyper/hyprland.conf
  if [[ ! -L $config -o $(readlink -f $config) = ${config2} ]]; then
    ln -sf ${config1} $config
  else
    ln -sf ${config2} $config
  fi
  hyprctl reload
'';

you could then use systemd-tmpfiles to make sure config1 was linked in place on activation. Install switcher into your packages. I’m sure I’ve typo’d at least one thing, but you get the idea?

1 Like
9

it almost worked. when running the switch command I get an error.
ln: failed to create symbolic link '/home/MatsuNoKi/.config/hyper/hyprland.conf': No such file or directory
also, -o didn’t work at first. took me a while to realize what it was but replacing it with || worked.

1 Like
10

ohp. hypr, not hyper

corrected the mistake.

it worked.