.. Licensed to the Apache Software Foundation (ASF) under one or more
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   with this work for additional information regarding copyright
   ownership.  The ASF licenses this file to you under the Apache
   License, Version 2.0 (the "License"); you may not use this file
   except in compliance with the License.  You may obtain a copy of
   the License at

   http://www.apache.org/licenses/LICENSE-2.0

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.. include:: ../../../common.defs

.. default-domain:: c

TSHostLookup
************

Synopsis
========

`#include <ts/ts.h>`

.. function:: TSAction TSHostLookup(TSCont contp, const char * hostname, size_t namelen)

Description
===========

Attempts host name resolution for the given :arg:`hostname` with length :arg:`namelen`. When a result is ready the handler of :arg:`contp` is called with the :macro:`TS_EVENT_HOST_LOOKUP` event and a :type:`TSHostLookupResult`. Use :func:`TSHostLookupResultAddrGet` to retrieve the resulting address from the :type:`TSHostLookupResult`.

A call to :func:`TSHostLookup` may be synchronous—in which case the handler for :arg:`contp` will be called with the answer before the call to :func:`TSHostLookup` returns—or the call to :func:`TSHostLookup` may be asynchronous—in which case it returns immediately with a :type:`TSAction`, and the handler :arg:`contp` will be called in the future. See :doc:`../../plugins/actions/index.en` for guidance.

In particular, :arg:`contp` must have been created with a :type:`TSMutex`; see :func:`TSContCreate`
