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 does anything, but it remains for backwards
       compatibility.  The function always return an empty string, or
       <symbol>NULL</symbol> if the <parameter>conn</parameter> argument is
       <symbol>NULL</symbol>.

<synopsis>
char *PQtty(const PGconn *conn);
</synopsis>
      </para>
     </listitem>
    </varlistentry>

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

     <listitem>
      <para>
       Returns the command-line options passed in the connection request.
<synopsis>
char *PQoptions(const PGconn *conn);
</synopsis>
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </para>

  <para>
   The following functions return status data that can change as operations
   are executed on the <structname>PGconn</structname> object.

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

     <listitem>
      <para>
       Returns the status of the connection.
<synopsis>
ConnStatusType PQstatus(const PGconn *conn);
</synopsis>
      </para>

      <para>
       The status can be one of a number of values.  However, only two of
       these are seen outside of an asynchronous connection procedure:
       <symbol>CONNECTION_OK</symbol> and
       <symbol>CONNECTION_BAD</symbol>. A good connection to the database
       has the status <symbol>CONNECTION_OK</symbol>.  A failed
       connection attempt is signaled by status
       <symbol>CONNECTION_BAD</symbol>.  Ordinarily, an OK status will
       remain so until <xref linkend="libpq-PQfinish"/>, but a communications
       failure might result in the status changing to
       <symbol>CONNECTION_BAD</symbol> prematurely.  In that case the
       application could try to recover by calling
       <xref linkend="libpq-PQreset"/>.
      </para>

      <para>
       See the entry for <xref linkend="libpq-PQconnectStartParams"/>, <function>PQconnectStart</function>
       and <function>PQconnectPoll</function> with regards to other status codes that
       might be returned.
      </para>
     </listitem>
    </varlistentry>

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

     <listitem>
      <para>
       Returns the current in-transaction status of the server.

<synopsis>
PGTransactionStatusType PQtransactionStatus(const PGconn *conn);
</synopsis>

       The status can be <literal>PQTRANS_IDLE</literal> (currently idle),
       <literal>PQTRANS_ACTIVE</literal> (a command is in progress),
       <literal>PQTRANS_INTRANS</literal> (idle, in a valid transaction block),
       or <literal>PQTRANS_INERROR</literal> (idle, in a failed transaction block).
       <literal>PQTRANS_UNKNOWN</literal> is reported if the connection is bad.
       <literal>PQTRANS_ACTIVE</literal>