specified both <literal>host</literal> and
       <literal>hostaddr</literal>, then <xref linkend="libpq-PQhost"/> will
       return the <literal>host</literal> information.  If only
       <literal>hostaddr</literal> was specified, then that is returned.
       If multiple hosts were specified in the connection parameters,
       <xref linkend="libpq-PQhost"/> returns the host actually connected to.
      </para>

      <para>
       <xref linkend="libpq-PQhost"/> returns <symbol>NULL</symbol> if the
       <parameter>conn</parameter> argument is <symbol>NULL</symbol>.
       Otherwise, if there is an error producing the host information (perhaps
       if the connection has not been fully established or there was an
       error), it returns an empty string.
      </para>

      <para>
       If multiple hosts were specified in the connection parameters, it is
       not possible to rely on the result of <xref linkend="libpq-PQhost"/> until
       the connection is established.  The status of the connection can be
       checked using the function <xref linkend="libpq-PQstatus"/>.
      </para>
     </listitem>
    </varlistentry>


    <varlistentry id="libpq-PQhostaddr">
     <term><function>PQhostaddr</function><indexterm><primary>PQhostaddr</primary></indexterm></term>

     <listitem>
      <para>
       Returns the server IP address of the active connection.
       This can be the address that a host name resolved to,
       or an IP address provided through the <literal>hostaddr</literal>
       parameter.
<synopsis>
char *PQhostaddr(const PGconn *conn);
</synopsis>
      </para>

      <para>
       <xref linkend="libpq-PQhostaddr"/> returns <symbol>NULL</symbol> if the
       <parameter>conn</parameter> argument is <symbol>NULL</symbol>.
       Otherwise, if there is an error producing the host information
       (perhaps if the connection has not been fully established or
       there was an error), it returns an empty string.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="libpq-PQport">
     <term><function>PQport</function><indexterm><primary>PQport</primary></indexterm></term>

     <listitem>
      <para>
       Returns the port of the active connection.

<synopsis>
char *PQport(const PGconn *conn);
</synopsis>
      </para>

      <para>
       If multiple ports were specified in the connection parameters,
       <xref linkend="libpq-PQport"/> returns the port actually connected to.
      </para>

      <para>
       <xref linkend="libpq-PQport"/> returns <symbol>NULL</symbol> if the
       <parameter>conn</parameter> argument is <symbol>NULL</symbol>.
       Otherwise, if there is an error producing the port information (perhaps
       if the connection has not been fully established or there was an
       error), it returns an empty string.
      </para>

      <para>
       If multiple ports were specified in the connection parameters, it is
       not possible to rely on the result of <xref linkend="libpq-PQport"/> until
       the connection is established.  The status of the connection can be
       checked using the function <xref linkend="libpq-PQstatus"/>.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="libpq-PQservice">
     <term><function>PQservice</function><indexterm><primary>PQservice</primary></indexterm></term>

     <listitem>
      <para>
       Returns the service of the active connection.

<synopsis>
char *PQservice(const PGconn *conn);
</synopsis>
      </para>

      <para>
       <xref linkend="libpq-PQservice"/> returns <symbol>NULL</symbol> if the
       <parameter>conn</parameter> argument is <symbol>NULL</symbol>.
       Otherwise, if there was no service provided, it returns an empty string.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry id="libpq-PQtty">
     <term><function>PQtty</function><indexterm><primary>PQtty</primary></indexterm></term>

     <listitem>
      <para>
       This function no longer