curl_easy_perform - perform a blocking file transfer
#include <curl/curl.h>
CURLcode curl_easy_perform(CURL *easy_handle);
Invoke this function after
curl_easy_init(3) and all the
curl_easy_setopt(3) calls are made, and it performs the transfer as
described in the options. It must be called with the same
easy_handle
as input as the
curl_easy_init(3) call returned.
performs the entire request in a blocking manner and
returns when done, or earlier if it fails. For non-blocking behavior, see
curl_multi_perform(3).
You can do any amount of calls to while using the
same
easy_handle. If you intend to transfer more than one file, you are
even encouraged to do so. libcurl will then attempt to re-use the same
connection for the following transfers, thus making the operations faster,
less CPU intense and using less network resources. Just note that you will
have to use
curl_easy_setopt(3) between the invokes to set options for
the following curl_easy_perform.
You must never call this function simultaneously from two places using the same
easy_handle. Let the function return first before invoking it another
time. If you want parallel transfers, you must use several curl easy_handles.
A network transfer moves data to a peer or from a peer. An application tells
libcurl how to receive data by setting the
CURLOPT_WRITEFUNCTION(3) and
CURLOPT_WRITEDATA(3) options. To tell libcurl what data to send, there
are a few more alternatives but two common ones are
CURLOPT_READFUNCTION(3) and
CURLOPT_POSTFIELDS(3).
While the
easy_handle is added to a multi handle, it cannot be used by
.
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
Always
CURLE_OK (0) means everything was OK, non-zero means an error occurred as
<curl/curl.h> defines - see
libcurl-errors(3). If the
CURLOPT_ERRORBUFFER(3) was set with
curl_easy_setopt(3) there
will be a readable error message in the error buffer when non-zero is
returned.
curl_easy_init(3),
curl_easy_setopt(3),
curl_multi_add_handle(3),
curl_multi_perform(3),
libcurl-errors(3),