Is value set with CURLOPT_USERAGENT overriden when using custom headers with CURLOPT_HTTPHEADER?

[ribtoks]

I mean when CURLOPT_HTTPHEADER is set with any headers. Do the "shortcuts" like _USERAGENT, _REFERRER etc. are thrown away?

It is not exactly clear from documentation.

[jay]

In recent versions the header list overrides the set user agent and referer but I'm not sure if it's always been that way. I would set one or the other. Is there a reason you need to set both?

[ribtoks]

@jay thanks for answering. I was setting USER_AGENT because it was a separate option but did not observe it in the logs of the request that was being sent so it was quite confusing.

[jay]

To clarify, if you set CURLOPT_HTTPHEADER with a User-Agent header that will override the user agent set via CURLOPT_USERAGENT. If you set CURLOPT_HTTPHEADER without a User-Agent header then libcurl will use CURLOPT_USERAGENT. This behavior is undocumented and therefore subject to change. Use one or the other to set the user agent.

[ribtoks]

All right, understood. Thank you!