CDE/cde/doc/C/guides/man/m3_Dt/MmdbDGPS.sgm

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<![ %CDE.C.CDE; [<refentry id="CDE.INFO.DtMmdbDlpGetPrevSection">]]><refmeta><refentrytitle>
DtMmdbDlpGetPrevSectionId</refentrytitle><manvolnum>library call</manvolnum></refmeta><refnamediv>
<refname><function>DtMmdbDlpGetPrevSectionId</function></refname><refpurpose>obtains
the object identifier of the previous section</refpurpose></refnamediv><refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;DtMmdb.h></funcsynopsisinfo>
<funcdef>DtMmdbHandle* <function>DtMmdbDlpGetPrevSectionId</function></funcdef>
<paramdef>DtMmdbInfoRequest* <parameter>request</parameter></paramdef>
</funcsynopsis>
</refsynopsisdiv><refsect1>
<title>DESCRIPTION</title>
<para>The <function>DtMmdbDlpGetPrevSectionId</function> function
returns the object identifier of the previous section. You can use
this function to traverse the TOC hierarchy in a depth-first fashion.
</para>
<para>Use the <function>DtMmdbFreeHandleList</function>
function to release the memory when the object identifier is no
longer needed. Table lookup is involved.
</para>
</refsect1><refsect1>
<title>ARGUMENTS</title>
<variablelist>
<varlistentry><term><symbol role="Variable">request</symbol></term>
<listitem>
<para>Specifies the bookcase in the bookcase descriptor field, as well
as the id of the current section in the
<symbol role="Variable">primary_oid</symbol> field.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1><refsect1>
<title>RETURN VALUE</title>
<para>If <function>DtMmdbDlpGetPrevSectionId</function> completes
successfully, it returns a pointer to the object identifier
for the previous section or
<SystemItem Class="Constant">DtMmdbGroundId</SystemItem>,
if there is no previous section.
If it fails, it returns a NULL pointer.
</para>
</refsect1><refsect1>
<title>EXAMPLE</title>
<para>The following shows how a <function>DtMmdbDlpGetPrevSectionId</function> call
might be coded.</para>
<informalexample>
<programlisting>DtMmdbInfoRequest request;
/* fill the request here */
DtMmdbHandle* x = DtMmdbDlpGetPrevSectionId(&amp;request);
if ( x == DtMMdbGroundId) {
   /* no previous section */
} else
  {
   if (x == 0) {
     /* bad request */
  }
  else
  { /* make use of x */
  }
</programlisting>
</informalexample>
</refsect1><refsect1>
<title>SEE ALSO</title>
<para>&cdeman.DtMmdbDlpGetNextSectionId;
</para>
</refsect1></refentry>