Set TMUX shell based on condition

nix/home.nix

@@ -533,6 +533,7 @@ in
       plugins = with pkgs; [ tmuxPlugins.cpu ];
       prefix = "C-s";
       terminal = "tmux-256color";
+      shell = if isLinux then "${pkgs.zsh}/bin/zsh" else "/bin/zsh";
 
       extraConfig = ''
         bind-key C command-prompt -p "Name of new window: " "new-window -n '%%'"
@@ -641,6 +642,13 @@ in
         set -o vi
         export EDITOR="nvim";
         export PS1="\n[\[\e[37m\]\u\[\e[0m\]@\[\e[37;2m\]\h\[\e[0m\]] \[\e[1m\]\w \[\e[0;2m\]J:\[\e[0m\]\j\n\$ ";
+
+        if [[ -z $TMUX ]]; then
+          tmux attach
+          if [[ $? == 1 ]]; then
+            tmux new -s main
+          fi
+        fi
       '';
     };
 
@@ -672,6 +680,13 @@ in
 
         set -o vi
         export EDITOR="nvim";
+
+        if [[ -z $TMUX ]]; then
+          tmux attach
+          if [[ $? == 1 ]]; then
+            tmux new -s main
+          fi
+        fi
       '';
     };