curl_easy_duphandle.3

.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  Project                     ___| | | |  _ \| |
.\" *                             / __| | | | |_) | |
.\" *                            | (__| |_| |  _ <| |___
.\" *                             \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
.\" *
.\" * This software is licensed as described in the file COPYING, which
.\" * you should have received as part of this distribution. The terms
.\" * are also available at https://curl.se/docs/copyright.html.
.\" *
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
.\" *
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
.\" * KIND, either express or implied.
.\" *
.\" * SPDX-License-Identifier: curl
.\" *
.\" **************************************************************************
.TH curl_easy_duphandle 3 "19 Sep 2014" "libcurl" "libcurl"
.SH NAME
curl_easy_duphandle - Clone a libcurl session handle
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURL *curl_easy_duphandle(CURL *handle);
.fi
.SH DESCRIPTION
This function will return a new curl handle, a duplicate, using all the
options previously set in the input curl \fIhandle\fP. Both handles can
subsequently be used independently and they must both be freed with
\fIcurl_easy_cleanup(3)\fP.

All strings that the input handle has been told to point to (as opposed to
copy) with previous calls to \fIcurl_easy_setopt(3)\fP using char * inputs,
will be pointed to by the new handle as well. You must therefore make sure to
keep the data around until both handles have been cleaned up.

The new handle will \fBnot\fP inherit any state information, no connections,
no SSL sessions and no cookies. It also will not inherit any share object
states or options (it will be made as if \fICURLOPT_SHARE(3)\fP was set to
NULL).

In multi-threaded programs, this function must be called in a synchronous way,
the input handle may not be in use when cloned.
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
CURL *nother;
if(curl) {
  CURLcode res;
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
  nother = curl_easy_duphandle(curl);
  res = curl_easy_perform(nother);
  curl_easy_cleanup(nother);
  curl_easy_cleanup(curl);
}
.fi
.SH AVAILABILITY
Added in 7.9
.SH RETURN VALUE
If this function returns NULL, something went wrong and no valid handle was
returned.
.SH "SEE ALSO"
.BR curl_easy_init "(3)," curl_easy_cleanup "(3)," curl_easy_reset "(3),"
.BR curl_global_init "(3)"