---

c: Copyright (C) Daniel Stenberg, daniel@haxx.se, et al. SPDX-License-Identifier: curl Title: CURLOPT_HTTP09_ALLOWED Section: 3 Source: libcurl Protocol:

• HTTP See-also:
• CURLOPT_HTTP_VERSION (3)
• CURLOPT_SSLVERSION (3) Added-in: 7.64.0

---

NAME

CURLOPT_HTTP09_ALLOWED - allow HTTP/0.9 response

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTP09_ALLOWED, long allowed);

DESCRIPTION

Pass the long argument allowed set to 1L to allow HTTP/0.9 responses.

An HTTP/0.9 response is a server response entirely without headers and only a body. You can connect to lots of random TCP services and still get a response that curl might consider to be HTTP/0.9.

DEFAULT

0

%PROTOCOLS%

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode ret;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    curl_easy_setopt(curl, CURLOPT_HTTP09_ALLOWED, 1L);
    ret = curl_easy_perform(curl);
  }
}

HISTORY

curl allowed HTTP/0.9 responses by default before 7.66.0

Since 7.66.0, libcurl requires this option set to 1L to allow HTTP/0.9 responses.

%AVAILABILITY%

RETURN VALUE

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

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).