owercase if specified.
Both <code>.shp</code> and <code>.shx</code> files must exist at the specified path.</p>
<p>Argument <var>access</var> are passed to <code>fopen(3)</code> through
<a href="#label-92">ShapeLib</a> <code>SHPOpen()</code> function.
Either '<code>rb</code>' or '<code>rb+</code>' should be used.</p>
<p>If a block is given to these constructors,
the opened shapefile object is yielded like File::open.
The shapefile is closed at the end of block,
and the constructor returns <code>nil</code>.<