curl/docs/libcurl/curl_easy_perform.3

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.TH curl_easy_perform 3 "5 Mar 2001" "libcurl 7.7" "libcurl Manual"
.SH NAME
curl_easy_perform - perform a blocking file transfer
.SH SYNOPSIS
.B #include <curl/curl.h>
.sp
.BI "CURLcode curl_easy_perform(CURL *" easy_handle ");"
.ad
.SH DESCRIPTION
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.

\fIcurl_easy_perform(3)\fP performs the entire request in a blocking manner
and returns when done, or earlier if it fails. For non-blocking behavior, see
\fIcurl_multi_perform(3)\fP.

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 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 \fIcurl_easy_setopt(3)\fP 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 \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 will be a readable error message 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), "