the
    application because the internal representation of the
    <literal>FILE</literal> pointers differ.  Specifically,
    multithreaded/single-threaded, release/debug, and static/dynamic
    flags should be the same for the library and all applications using
    that library.
    </para>
    </note>
   </listitem>

   <listitem>
     <para>
       <function>ECPGget_PGconn(const char *<replaceable>connection_name</replaceable>)
       </function> returns the library database connection handle identified by the given name.
       If <replaceable>connection_name</replaceable> is set to <literal>NULL</literal>, the current
       connection handle is returned. If no connection handle can be identified, the function returns
       <literal>NULL</literal>. The returned connection handle can be used to call any other functions
       from <application>libpq</application>, if necessary.
     </para>
     <note>
     <para>
       It is a bad idea to manipulate database connection handles made from <application>ecpg</application> directly
       with <application>libpq</application> routines.
     </para>
     </note>
   </listitem>

   <listitem>
     <para>
       <function>ECPGtransactionStatus(const char *<replaceable>connection_name</replaceable>)</function>
       returns the current transaction status of the given connection identified by <replaceable>connection_name</replaceable>.
       See <xref linkend="libpq-status"/> and libpq's <xref linkend="libpq-PQtransactionStatus"/> for details about the returned status codes.
     </para>
   </listitem>

   <listitem>
    <para>
     <function>ECPGstatus(int <replaceable>lineno</replaceable>,
     const char* <replaceable>connection_name</replaceable>)</function>
     returns true if you are connected to a database and false if not.
     <replaceable>connection_name</replaceable> can be <literal>NULL</literal>
     if a single connection is being used.
    </para>
   </listitem>
  </itemizedlist>
 </sect1>

 <sect1 id="ecpg-lo">
  <title>Large Objects</title>

  <para>
   Large objects are not directly supported by ECPG, but ECPG
   application can manipulate large objects through the libpq large
   object functions, obtaining the necessary <type>PGconn</type>
   object by calling the <function>ECPGget_PGconn()</function>
   function.  (However, use of
   the <function>ECPGget_PGconn()</function> function and touching
   <type>PGconn</type> objects directly should be done very carefully
   and ideally not mixed with other ECPG database access calls.)
  </para>

  <para>
   For more details about the <function>ECPGget_PGconn()</function>, see
   <xref linkend="ecpg-library"/>.  For information about the large
   object function interface, see <xref linkend="largeobjects"/>.
  </para>

  <para>
   Large object functions have to be called in a transaction block, so
   when autocommit is off, <command>BEGIN</command> commands have to
   be issued explicitly.
  </para>

  <para>
   <xref linkend="ecpg-lo-example"/> shows an example program that
   illustrates how to create, write, and read a large object in an
   ECPG application.
  </para>

  <example id="ecpg-lo-example">
   <title>ECPG Program Accessing Large Objects</title>
<programlisting><![CDATA[
#include <stdio.h>
#include <stdlib.h>
#include <libpq-fe.h>
#include <libpq/libpq-fs.h>

EXEC SQL WHENEVER SQLERROR STOP;

int
main(void)
{
    PGconn     *conn;
    Oid         loid;
    int         fd;
    char        buf[256];
    int         buflen = 256;
    char        buf2[256];
    int         rc;

    memset(buf, 1, buflen);

    EXEC SQL CONNECT TO testdb AS con1;
    EXEC SQL SELECT pg_catalog.set_config('search_path', '', false); EXEC SQL COMMIT;

    conn = ECPGget_PGconn("con1");
    printf("conn = %p\n", conn);

    /* create */
    loid = lo_create(conn, 0);
    if (loid &lt; 0)
        printf("lo_create() failed: %s", PQerrorMessage(conn));

    printf("loid = %d\n", loid);

    /* write test */
    fd = lo_open(conn,