.\" generated by cd2nroff 0.1 from CURLOPT_POST.md
.TH CURLOPT_POST 3 "2026-09-10" libcurl
.SH NAME
CURLOPT_POST \- make an HTTP POST
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_POST, long post);
.fi
.SH DESCRIPTION
A parameter set to 1 tells libcurl to do a regular HTTP post. This also makes
libcurl use a "Content\-Type: application/x\-www\-form\-urlencoded" header. This
is the most commonly used POST method.

Use one of \fICURLOPT_POSTFIELDS(3)\fP or \fICURLOPT_COPYPOSTFIELDS(3)\fP
options to specify what data to post and \fICURLOPT_POSTFIELDSIZE(3)\fP or
\fICURLOPT_POSTFIELDSIZE_LARGE(3)\fP to set the data size.

Optionally, you can provide data to POST using the
\fICURLOPT_READFUNCTION(3)\fP and \fICURLOPT_READDATA(3)\fP options but then
you must make sure to not set \fICURLOPT_POSTFIELDS(3)\fP 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
\fICURLOPT_POSTFIELDSIZE(3)\fP or \fICURLOPT_POSTFIELDSIZE_LARGE(3)\fP
options. To enable chunked encoding, 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 \fICURLOPT_HTTPHEADER(3)\fP.

Using POST with HTTP 1.1 implies the use of a "Expect: 100\-continue" header.
You can disable this header with \fICURLOPT_HTTPHEADER(3)\fP 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 \fICURLOPT_HTTPHEADER(3)\fP.
With HTTP 1.0 or without chunked transfer, you must specify the size in the
request. libcurl automatically uses chunked encoding for POSTs if the size is
unknown.

When setting \fICURLOPT_POST(3)\fP to 1, libcurl automatically sets
\fICURLOPT_NOBODY(3)\fP and \fICURLOPT_HTTPGET(3)\fP to 0.

If you issue a POST request and then want to make a HEAD or GET using the same
reused handle, you must explicitly set the new request type using
\fICURLOPT_NOBODY(3)\fP or \fICURLOPT_HTTPGET(3)\fP or similar.

When setting \fICURLOPT_POST(3)\fP to 0, libcurl resets the request type to the
default to disable the POST. Typically that means gets reset to GET. Instead
you should set a new request type explicitly as described above.
.SH DEFAULT
0, disabled
.SH PROTOCOLS
This functionality affects http only
.SH EXAMPLE
.nf
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
    curl_easy_setopt(curl, CURLOPT_POST, 1L);

    /* set up the read callback with CURLOPT_READFUNCTION */

    result = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
  }
}
.fi
.SH AVAILABILITY
Added in curl 7.1
.SH RETURN VALUE
\fIcurl_easy_setopt(3)\fP returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non\-zero means an error occurred, see
\fIlibcurl\-errors(3)\fP.
.SH SEE ALSO
.BR CURLOPT_HTTPPOST (3),
.BR CURLOPT_POSTFIELDS (3),
.BR CURLOPT_UPLOAD (3)