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.\" **************************************************************************
.\" * _ _ ____ _
.\" * Project ___| | | | _ \| |
.\" * / __| | | | |_) | |
.\" * | (__| |_| | _ <| |___
.\" * \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) 1998 - 2015, 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
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.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
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.\" **************************************************************************
.\"
.TH CURLOPT_TCP_KEEPALIVE 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_TCP_KEEPALIVE \- enable TCP keep-alive probing
.SH SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_KEEPALIVE, long probe);
.SH DESCRIPTION
Pass a long. If set to 1, TCP keepalive probes will be sent. The delay and
frequency of these probes can be controlled by the
\fICURLOPT_TCP_KEEPIDLE(3)\fP and \fICURLOPT_TCP_KEEPINTVL(3)\fP options,
provided the operating system supports them. Set to 0 (default behavior) to
disable keepalive probes
.SH DEFAULT
0
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
/* enable TCP keep-alive for this transfer */
curl_easy_setopt(curl, CURLOPT_TCP_KEEPALIVE, 1L);
/* keep-alive idle time to 120 seconds */
curl_easy_setopt(curl, CURLOPT_TCP_KEEPIDLE, 120L);
/* interval time between keep-alive probes: 60 seconds */
curl_easy_setopt(curl, CURLOPT_TCP_KEEPINTVL, 60L);
curl_easy_perform(curl);
}
.fi
.SH AVAILABILITY
Added in 7.25.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR CURLOPT_TCP_KEEPIDLE "(3), " CURLOPT_TCP_KEEPINTVL "(3), "
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