CURLOPT_POSTFIELDS(3)      curl_easy_setopt options      CURLOPT_POSTFIELDS(3)

NAME
       CURLOPT_POSTFIELDS - specify data to POST to server

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_POSTFIELDS, char
       *postdata);

DESCRIPTION
       Pass a char * as parameter, pointing to the full data to send in an
       HTTP POST operation. You must make sure that the data is formatted the
       way you want the server to receive it. libcurl will not convert or
       encode it for you in any way. For example, the web server may assume
       that this data is url-encoded.

       The data pointed to is NOT copied by the library: as a consequence, it
       must be preserved by the calling application until the associated
       transfer finishes.  This behavior can be changed (so libcurl does copy
       the data) by setting the _COPYPOSTFIELDS&section=3">CURLOPT_COPYPOSTFIELDS(3) option.

       This POST is a normal application/x-www-form-urlencoded kind (and
       libcurl will set that Content-Type by default when this option is
       used), which is commonly used by HTML forms. Change Content-Type with
       _HTTPHEADER&section=3">CURLOPT_HTTPHEADER(3).

       You can use _easy_escape&section=3">curl_easy_escape(3) to url-encode your data, if necessary.
       It returns a pointer to an encoded string that can be passed as
       postdata.

       Using _POSTFIELDS&section=3">CURLOPT_POSTFIELDS(3) implies setting _POST&section=3">CURLOPT_POST(3) to 1.

       If _POSTFIELDS&section=3">CURLOPT_POSTFIELDS(3) is explicitly set to NULL then libcurl will
       get the POST data from the read callback. If you want to send a zero-
       byte POST set _POSTFIELDS&section=3">CURLOPT_POSTFIELDS(3) to an empty string, or set
       _POST&section=3">CURLOPT_POST(3) to 1 and _POSTFIELDSIZE&section=3">CURLOPT_POSTFIELDSIZE(3) to 0.

       libcurl will use assume this option points to a nul-terminated string
       unless you also set _POSTFIELDSIZE&section=3">CURLOPT_POSTFIELDSIZE(3) to specify the length of
       the provided data, which then is strictly required if you want to send
       off nul bytes included in the data.

       Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue"
       header, and libcurl will add that header automatically if the POST is
       either known to be larger than 1MB or if the expected size is unknown.
       You can disable this header with _HTTPHEADER&section=3">CURLOPT_HTTPHEADER(3) as usual.

       To make multipart/formdata posts (aka RFC2388-posts), check out the
       _HTTPPOST&section=3">CURLOPT_HTTPPOST(3) option combined with _formadd&section=3">curl_formadd(3).

DEFAULT
       NULL

PROTOCOLS
       HTTP

EXAMPLE
       CURL *curl = curl_easy_init();
       if(curl) {
         const char *data = "data to send";

         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

         /* size of the POST data */
         curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, 12L);

         /* pass in a pointer to the data - libcurl will not copy */
         curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data);

         curl_easy_perform(curl);
       }

AVAILABILITY
       Always

RETURN VALUE
       Returns CURLE_OK

SEE ALSO
       CURLOPT_POSTFIELDSIZE(3), CURLOPT_READFUNCTION(3),

libcurl 7.77.0                  April 23, 2021           CURLOPT_POSTFIELDS(3)