code: def DviPdfPsFunction(XXXDviAction, target = None, source= None, env=None):
      
  
      try:
          abspath = source[0].attributes.path
      except AttributeError :
          abspath =  ''
  
      saved_env = SCons.Scanner.LaTeX.modify_env_var(env, 'TEXPICTS', abspath)
  
      result = XXXDviAction(target, source, env)
  
      if saved_env is _null:
          try:
              del env['ENV']['TEXPICTS']
          except KeyError:
              pass # was never set
      else:
          env['ENV']['TEXPICTS'] = saved_env
  
      return result
docs: A builder for DVI files that sets the TEXPICTS environment
         variable before running dvi2ps or dvipdf.