title: How to append specific url param to the redirected URL in nginx
body: <p>In nginx, I am redirecting a URL with a param like: </p>
  
  <p>www.example.com/xyz?var1=ty&amp;var2=po&amp;var3=k  to </p>
  
  <p>www.example.com/anything?a=1&amp;<strong>b=po_k</strong></p>
  
  <p>in redirectedURL  <strong>b=po_k</strong> is combination of source url var2 and var3 . </p>
  
  <p>Can someone help on this?</p>