curl_easy_perform

Section: libcurl Manual (3)
Updated: November 04, 2020
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NAME

curl_easy_perform - perform a blocking file transfer

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_perform(CURL *easy_handle);

DESCRIPTION

Invoke this function after curl_easy_init(3) and all the curl_easy_setopt(3) calls are made, and will perform 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.

curl_easy_perform(3) performs the entire request in a blocking manner and returns when done, or if it failed. For non-blocking behavior, see curl_multi_perform(3).

You can do any amount of calls to curl_easy_perform(3) 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.

While the easy_handle is added to a multi handle, it cannot be used by curl_easy_perform(3).

RETURN VALUE

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.

EXAMPLE

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);
}