teach clipboard tool about wayland

nixos/sway/default.nix

@@ -16,6 +16,9 @@ in
       home.sessionVariables = {
       };
 
+      home.packages = with pkgs; [
+        wl-clipboard
+      ];
 
       wayland.windowManager.sway = {
         enable = true;

tools/clipboard

@@ -1,2 +1,7 @@
 #!/usr/bin/env bash
-xclip -selection clipboard
+read contents
+if [[ -x `which wl-copy` ]]; then
+    echo "$contents" | wl-copy
+else
+    echo "$contents" | xclip -selection clipboard
+fi