Add a toggle in the bar for microphone loopback

bar.nix

@@ -260,9 +260,9 @@
         };
 
         "custom/loopback" = lib.attrsets.optionalAttrs (variant == "default") {
-          exec = "if systemctl --user is-active --quiet loopback; then echo oui; else echo non; fi";
+          exec = "journalctl --user -f -u loopback | exec_on_stdin_newline 'if systemctl --user is-active --quiet loopback; then echo loopback ON; else echo loopback; fi'";
           on-click = "if systemctl --user is-active --quiet loopback; then systemctl --user stop loopback; else systemctl --user start loopback; fi";
-          format = "TEST {}";
+          format = "{}";
         };
 
         "hyprland/submap" = {

home.nix

@@ -50,6 +50,14 @@
       echo "$cwd"
     '';
 
+    ".bin/exec_on_stdin_newline".source = pkgs.writers.writePython3 "exec_on_stdin_newline" {} ''
+      # run command whjen a newline is added to stdin
+      import subprocess
+      from sys import stdin, argv
+      cmd = argv[1:]
+      while stdin.readline():
+          subprocess.call(cmd, shell=True)
+      '';
 
     ".bin/screenshot".source = (import ./bin/screenshot.nix) pkgs;