curl/docs/libcurl/opts/CURLOPT_POSTREDIR.md
Daniel Stenberg eefcc1bda4
docs: introduce "curldown" for libcurl man page format
curldown is this new file format for libcurl man pages. It is markdown
inspired with differences:

- Each file has a set of leading headers with meta-data
- Supports a small subset of markdown
- Uses .md file extensions for editors/IDE/GitHub to treat them nicely
- Generates man pages very similar to the previous ones
- Generates man pages that still convert nicely to HTML on the website
- Detects and highlights mentions of curl symbols automatically (when
  their man page section is specified)

tools:

- cd2nroff: converts from curldown to nroff man page
- nroff2cd: convert an (old) nroff man page to curldown
- cdall: convert many nroff pages to curldown versions
- cd2cd: verifies and updates a curldown to latest curldown

This setup generates .3 versions of all the curldown versions at build time.

CI:

Since the documentation is now technically markdown in the eyes of many
things, the CI runs many more tests and checks on this documentation,
including proselint, link checkers and tests that make sure we capitalize the
first letter after a period...

Closes #12730
2024-01-23 00:29:02 +01:00

2.1 KiB

c SPDX-License-Identifier Title Section Source See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al. curl CURLOPT_POSTREDIR 3 libcurl
CURLINFO_EFFECTIVE_METHOD (3)
CURLINFO_REDIRECT_COUNT (3)
CURLOPT_FOLLOWLOCATION (3)
CURLOPT_MAXREDIRS (3)
CURLOPT_POSTFIELDS (3)

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(3).

DEFAULT

0

PROTOCOLS

HTTP(S)

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.