CURLOPT_POSTREDIR(3)

💅 CURLOPT_POSTREDIR(3) — the curl manual, bestie edition ✨

okay so you're in the Library Functions Manual for curl, and today's main character is CURLOPT_POSTREDIR — literally the option that decides how your POST behaves when a redirect tries to humble it. 🎀

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🌸 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 🦋

So you pass in a bitmask and it controls how libcurl acts on redirects after POSTs that get a 301, 302 or 303 response back. Bestie, it's a whole little bitfield situation and every bit is doing its own thing:

• 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
• setting bit 2 (value CURL_REDIR_POST_303) makes libcurl maintain the request method after a 303 redirect

and the value CURL_REDIR_POST_ALL is a convenience define that sets all three bits at once — the "just do all of it" icon that it is 👑

The non-RFC behavior is, quote unquote, ubiquitous in web browsers, so the library does the conversion by default to maintain consistency. BUT — and this is the plot twist — a server may require a POST to remain a POST after such a redirection. So this option is meaningful only when setting CURLOPT_FOLLOWLOCATION(3). No followlocation, no redirect, no drama, this whole thing just vibing unused. 🙈

🍓 DEFAULT 🍓

0

🌈 PROTOCOLS 🌈

This functionality affects http only. that's it. that's the protocol. 💅

🧚 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);
  }
}

💜 HISTORY 💜

ngl the lore here is kind of iconic:

• this option was known as CURLOPT_POST301 up to 7.19.0 — because back then it only supported the 301, that was its whole personality
• CURL_REDIR_POST_303 was added in 7.26.0 ✨
• the CURL_REDIR_* macros became long types in 8.16.0 — prior to this version a long cast was necessary when passed to curl_easy_setopt(3)

⭐ AVAILABILITY ⭐

Added in curl 7.19.1

🔥 RETURN VALUE 🔥

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK — slay. Non-zero means an error occurred, so go see libcurl-errors(3) and figure out what went down. 😭

🌸 SEE ALSO 🌸

• CURLINFO_EFFECTIVE_METHOD(3)
• CURLINFO_REDIRECT_COUNT(3)
• CURLOPT_FOLLOWLOCATION(3)
• CURLOPT_MAXREDIRS(3)
• CURLOPT_POSTFIELDS(3)

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and that's the page, bestie 🫶 this was libcurl, dated 2026-10-12, filed under CURLOPT_POSTREDIR(3) — go keep those POSTs POSTing, mwah 💖