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<!--

  Copyright (c) 2001, 2002, 2003 Steven Knight

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-->

   <para>

   It's often very useful to be able to give
   users some help that describes the
   specific targets, build options, etc.,
   that can be used for the build.
   &SCons; provides the &Help; function
   to allow you to specify this help text:

   </para>

   <programlisting>
      Help("""
      Type: 'scons program' to build the production program,
            'scons debug' to build the debug version.
      """)
   </programlisting>

   <para>

   (Note the above use of the Python triple-quote syntax,
   which comes in very handy for
   specifying multi-line strings like help text.)

   </para>

   <para>

   When the &SConstruct; or &SConscript; files
   contain such a call to the &Help; function,
   the specified help text will be displayed in response to
   the &SCons; <literal>-h</literal> option:

   </para>

   <literallayout>
      % <userinput>scons -h</userinput>
      Type: 'scons program' to build the production program,
            'scons debug' to build the debug version.
   </literallayout>

   <para>

   If there is no &Help; text in the &SConstruct; or
   &SConscript; files,
   &SCons; will revert to displaying its
   standard list and description of available command-line
   options.
   This list is also always displayed whenever
   the <literal>-H</literal> option is used.

   </para>