CURLOPT_POSTFIELDS - data to POST to server
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_POSTFIELDS, char *postdata);
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
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
CURLOPT_HTTPHEADER(3).
You can use
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 implies setting
CURLOPT_POST(3) to 1.
If 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
to an empty string, or set
CURLOPT_POST(3)
to 1 and
CURLOPT_POSTFIELDSIZE(3) to 0.
libcurl will use assume this option points to a null-terminated string unless
you also set
CURLOPT_POSTFIELDSIZE(3) to specify the length of the
provided data, which then is strictly required if you want to send off null
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
CURLOPT_HTTPHEADER(3) as usual.
To make
multipart/formdata posts, check out the
CURLOPT_MIMEPOST(3) option combined with
curl_mime_init(3).
NULL
HTTP
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);
}
Always
Returns CURLE_OK
CURLOPT_POSTFIELDSIZE(3),
CURLOPT_READFUNCTION(3),
CURLOPT_MIMEPOST(3),
CURLOPT_UPLOAD(3),