Using Your Custom Build File

You can specify a custom build file to be used in DITA-OT transformations by editing the transformation scenario that you are using. In the Advanced tab you should change the Custom build file path to point to the custom build file.

As an example, if you want to call a custom script before running the DITA OT, your custom build file would have the following content:
<project basedir="." default="dist">
<!--The DITA OT default build file-->
 <import file="build.xml"/>
 <target name="dist">
  <!-- You could run your script here -->
  <!--<exec></exec>-->
   <!--Call the DITA OT default target-->
   <antcall target="init"/>
 </target>
</project>