Append to the query

An application can append a string to the right end of the existing query part with the CURLU_APPENDQUERY flag.
Consider a handle that holds the URL An application can then add the string hat=1 to the query part like this:
rc = curl_url_set(urlp, CURLUPART_QUERY, "hat=1", CURLU_APPENDQUERY);
It will even notice the lack of an ampersand (&) separator so it will inject one too, and the handle's full URL would then equal
The appended string can of course also get URL encoded on add, and if asked, the encoding will skip the '=' character. For example, append candy=M&M to what we already have, and URL encode it to deal with the ampersand in the data:
rc = curl_url_set(urlp, CURLUPART_QUERY, "candy=M&M",
Now the URL looks like