[Programs/Bash] Add powerline-go to bash by default

programs/bash.nix

@@ -0,0 +1,24 @@
+{ config, pkgs, lib, ... }:
+with lib;
+{
+  options.aviallon.programs.bash = {
+    powerline = mkOption {
+      description = "Enable powerline prompt";
+      default = true;
+      example = false;
+      type = types.bool;
+    };
+  };
+
+  config = {
+    programs.bash.promptInit = mkAfter ''
+      _prompt() {
+        PS1="$(${pkgs.powerline-go}/bin/powerline-go -error $? -jobs $(jobs -p | wc -l))"
+      }
+      if [ "$TERM" != "dumb" ] && [ "$TERM" != "linux" ]; then
+        export PROMPT_COMMAND="_prompt"
+      fi
+      export -f _prompt
+    '';
+  };
+}