curl/docs/libcurl/curl_easy_perform.3

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.TH curl_easy_perform 3 "5 Mar 2001" "libcurl" "libcurl"
.SH NAME
curl_easy_perform - perform a blocking file transfer
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_perform(CURL *easy_handle);
.fi
.SH DESCRIPTION
\fIcurl_easy_perform(3)\fP performs a network transfer in a blocking manner
and returns when done, or earlier if it fails. For non-blocking behavior, see
\fIcurl_multi_perform(3)\fP.

Invoke this function after \fIcurl_easy_init(3)\fP and all the
\fIcurl_easy_setopt(3)\fP calls are made, and it performs the transfer as
described in the options. It must be called with the same \fBeasy_handle\fP as
input as the \fIcurl_easy_init(3)\fP call returned.

You can do any amount of calls to \fIcurl_easy_perform(3)\fP while using the
same \fBeasy_handle\fP. 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
\fIcurl_easy_setopt(3)\fP between the invokes to set options for the following
curl_easy_perform call.

You must never call this function simultaneously from two places using the
same \fBeasy_handle\fP. 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 \fICURLOPT_WRITEFUNCTION(3)\fP and
\fICURLOPT_WRITEDATA(3)\fP options. To tell libcurl what data to send, there
are a few more alternatives but two common ones are
\fICURLOPT_READFUNCTION(3)\fP and \fICURLOPT_POSTFIELDS(3)\fP.

While the \fBeasy_handle\fP is added to a multi handle, it cannot be used by
\fIcurl_easy_perform(3)\fP.
.SH EXAMPLE
.nf
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);
}
.fi
.SH AVAILABILITY
Always
.SH RETURN VALUE
CURLE_OK (0) means everything was OK, non-zero means an error occurred as
.I <curl/curl.h>
defines - see \fIlibcurl-errors(3)\fP. If the \fICURLOPT_ERRORBUFFER(3)\fP was
set with \fIcurl_easy_setopt(3)\fP there is a readable error message stored in
the error buffer when non-zero is returned.
.SH "SEE ALSO"
.BR curl_easy_init "(3), " curl_easy_setopt "(3), "
.BR curl_multi_add_handle "(3), " curl_multi_perform "(3), "
.BR libcurl-errors "(3), "