avoid forking subshell to test if user is root

themes/dst.zsh-theme

@@ -5,7 +5,7 @@ ZSH_THEME_GIT_PROMPT_DIRTY="%{$fg[red]%}!"
 ZSH_THEME_GIT_PROMPT_CLEAN=""
 
 function prompt_char {
-	if [ "$(whoami)" = "root" ]; then echo "%{$fg[red]%}#%{$reset_color%}"; else echo $; fi
+	if [ $UID -eq 0 ]; then echo "%{$fg[red]%}#%{$reset_color%}"; else echo $; fi
 }
 
 PROMPT='%(?, ,%{$fg[red]%}FAIL%{$reset_color%}