Question

I’m using curl to post to a script.

curl_setopt ($ch, CURLOPT_POST, true);
curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch,CURLOPT_POSTFIELDS,$postvars);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch,CURLOPT_SSL_VERIFYHOST,0);

But there’s 301 redirect involved which casues curl to switch from POST to GET.

HTTP/1.1 301 Moved Permanently
< Location: https://myserver.org/php/callback-f.php
< Content-Length: 0
< Date: Wed, 16 Nov 2011 17:21:06 GMT
< Server: lighttpd/1.4.28
* Connection #0 to host myserver.org left intact
* Issue another request to this URL: 'https://myserver.org/php/callback-f.php'
* Violate RFC 2616/10.3.2 and switch from POST to GET
* About to connect() to myserver.org port 443

Does anyone know how I can prevent curl from switching to GET please?

Answer 1

CURLOPT_POSTREDIR can be set to configure this behaviour (request method for 301 location header based automatic redirects in curl):

curl_setopt( , CURLOPT_POSTREDIR, 3);

here 3 tells curl module to redirect both 301 as well as 302 requests.

0,1,2,3 are the valid options for the last argument.

0 -> do not set any behavior
1 -> follow redirect with the same type of request only for 301 redirects.
2 -> follow redirect with the same type of request only for 302 redirects.
3 -> follow redirect with the same type of request both for 301 and 302 redirects.

See as well: Request #49571 CURLOPT_POSTREDIR not implemented which has some useful comments, like setting a custom request method:

curl_setopt( $ch, CURLOPT_CUSTOMREQUEST, "POST");