CURLOPT_EXPECT_100_TIMEOUT_MS - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_EXPECT_100_TIMEOUT_MS,
                          long milliseconds);

Pass a long to tell libcurl the number of milliseconds to wait for a server response with the HTTP status 100 (Continue), 417 (Expectation Failed) or similar after sending an HTTP request containing an Expect: 100-continue header. If this times out before a response is received, the request body is sent anyway.

1000 milliseconds

HTTP

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

  /* wait 3 seconds for 100-continue */
  curl_easy_setopt(curl, CURLOPT_EXPECT_100_TIMEOUT_MS, 3000L);

  curl_easy_perform(curl);
}

Added in 7.36.0

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

CURLOPT_POST(3), CURLOPT_HTTPPOST(3),

curl_easy_setopt(3).