Tribblix: manual page: curl_easy

curl_easy_perform(3) Introduction to Library Functions curl_easy_perform(3)

NAME

curl_easy_perform - perform a blocking network transfer

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_perform(CURL *easy_handle);

DESCRIPTION

curl_easy_perform(3) performs a network transfer in a blocking manner
and returns when done, or earlier if it fails. For non-blocking
behavior, see curl_multi_perform(3).

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.

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 attempts to reuse existing
connections for the following transfers, thus making the operations
faster, less CPU intense and using less network resources. You
probably want to use curl_easy_setopt(3) between the invokes to set
options for the following curl_easy_perform(3) call.

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_easy_perform(3).

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE

int main(void)
{
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);
}
}

AVAILABILITY

Added in curl 7.1

RETURN VALUE

This function returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3). If CURLOPT_ERRORBUFFER(3) was set
with curl_easy_setopt(3) there can be an error message stored in the
error buffer when non-zero is returned.