curl / libcurl / API / curl_easy_setopt / CURLOPT_POSTREDIR

CURLOPT_POSTREDIR explained

Name

CURLOPT_POSTREDIR - how to act on an HTTP POST redirect

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_POSTREDIR,
                          long bitmask);

Description

Pass a bitmask to control how libcurl acts on redirects after POSTs that get a 301, 302 or 303 response back. A parameter with bit 0 set (value CURL_REDIR_POST_301) tells the library to respect RFC 7231 (section 6.4.2 to 6.4.4) and not convert POST requests into GET requests when following a 301 redirection. Setting bit 1 (value CURL_REDIR_POST_302) makes libcurl maintain the request method after a 302 redirect whilst setting bit 2 (value CURL_REDIR_POST_303) makes libcurl maintain the request method after a 303 redirect. The value CURL_REDIR_POST_ALL is a convenience define that sets all three bits.

The non-RFC behavior is ubiquitous in web browsers, so the library does the conversion by default to maintain consistency. However, a server may require a POST to remain a POST after such a redirection. This option is meaningful only when setting CURLOPT_FOLLOWLOCATION.

Default

Protocols

HTTP

Example

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
 
    /* a silly POST example */
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "data=true");
 
    /* example.com is redirected, so we tell libcurl to send POST on 301,
       302 and 303 HTTP response codes */
    curl_easy_setopt(curl, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 
    curl_easy_perform(curl);
  }
}

Availability

Added in 7.17.1. This option was known as CURLOPT_POST301 up to 7.19.0 as it only supported the 301 then. CURL_REDIR_POST_303 was added in 7.26.0.

Return value

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.