How can I split my polygon file into "segements"? The lines should be broken up like this picture shows:
Edit: The above method will not give you duplicates at d and f. If duplicate segments are required, you could probably replace the first step(v.type.bl) with the Qgis Polygons to Lines tool(Vector -> Geometry tools -> Polygons to Lines).
Edit#2 - "Any number of Points in a segment" seems a little confusing. You can specify the maximun segment length, or maximum number of vertices to refine your needs in
I understand that you want to turn your polygons into individual line segments, and that your concern is that segments d & f will not be created as separate lines?
After running that procedure on two simple polygons, just as you show in your example, I ended up with 8 features, two of which are overlapping lines (corresponding to d & f); in the screenshot below, the 'id' refers to the original polygons, and each row is a separate line segment..