DOKK / manpages / debian 10 / libcurl4-doc / CURLOPT_POST.3.en
CURLOPT_POST(3) curl_easy_setopt options CURLOPT_POST(3)

CURLOPT_POST - request an HTTP POST

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_POST, long post);

A parameter set to 1 tells libcurl to do a regular HTTP post. This will also make the library use a "Content-Type: application/x-www-form-urlencoded" header. (This is by far the most commonly used POST method).

Use one of CURLOPT_POSTFIELDS(3) or CURLOPT_COPYPOSTFIELDS(3) options to specify what data to post and CURLOPT_POSTFIELDSIZE(3) or CURLOPT_POSTFIELDSIZE_LARGE(3) to set the data size.

Optionally, you can provide data to POST using the CURLOPT_READFUNCTION(3) and CURLOPT_READDATA(3) options but then you must make sure to not set CURLOPT_POSTFIELDS(3) to anything but NULL. When providing data with a callback, you must transmit it using chunked transfer-encoding or you must set the size of the data with the CURLOPT_POSTFIELDSIZE(3) or CURLOPT_POSTFIELDSIZE_LARGE(3) options. To enable chunked encoding, you simply pass in the appropriate Transfer-Encoding header, see the post-callback.c example.

You can override the default POST Content-Type: header by setting your own with CURLOPT_HTTPHEADER(3).

Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header. You can disable this header with CURLOPT_HTTPHEADER(3) as usual.

If you use POST to an HTTP 1.1 server, you can send data without knowing the size before starting the POST if you use chunked encoding. You enable this by adding a header like "Transfer-Encoding: chunked" with CURLOPT_HTTPHEADER(3). With HTTP 1.0 or without chunked transfer, you must specify the size in the request.

When setting CURLOPT_POST(3) to 1, libcurl will automatically set CURLOPT_NOBODY(3) and CURLOPT_HTTPGET(3) to 0.

If you issue a POST request and then want to make a HEAD or GET using the same re-used handle, you must explicitly set the new request type using CURLOPT_NOBODY(3) or CURLOPT_HTTPGET(3) or similar.

0, disabled

HTTP

CURL *curl = curl_easy_init();
if(curl) {

curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/foo.bin");
curl_easy_setopt(curl, CURLOPT_POST, 1L);
/* set up the read callback with CURLOPT_READFUNCTION */
ret = curl_easy_perform(curl);
curl_easy_cleanup(curl); }

Along with HTTP

Returns CURLE_OK if HTTP is supported, and CURLE_UNKNOWN_OPTION if not.

CURLOPT_POSTFIELDS(3), CURLOPT_HTTPPOST(3),

May 21, 2018 libcurl 7.64.0