Shrink-Extend Line

                                        
Trims or lengthens a line so that it meets another object. Double lines and multi lines can also be used.

1. Select the line you want to shrink or extend. Click near the endpoint you want to move.
2. Select the object that the line is to meet. The endpoint of the line meets the selected object.

When shrinking a line, be sure to click near the endpoint that will move, otherwise the wrong part of the line will be deleted.

Local menu option:
Cleanup: Relevant for double lines, makes the cutlines invisible, forming a clean intersection. See Double Line Options
Note: You can use Shrink / Extend Line on splines and Beziers, however the extension will be straight element of the curve, not curved continuations as they are with arcs.
Note: Most standard Modify tools, such as Trim, Split, and Meet 2 Lines, will work with walls.