revpath - generate a relative path that can be used to undo a change-directory
revpath program prints out a relative path that is the reverse or inverse of
path. Start with two directories
bottom, with the latter below the former, and
path is the location of
bottom relative to
top. The output of
revpath is the location of
top relative to
bottom. The resulting path contains a trailing / character when the result is
path is equivalent to ., the resulting output is empty.
path is invalid in some way (e.g., doesnt represent the path to a subdirectory)
the output is also empty and no error messages are ever generated.
There are no diagnostics. Error conditions are silently ignored, and the
exit status is always 0.
It isnt possible to reverse arbitrary relative paths.
If any path element between the two end points of
path is a symbolic link, the results will probably be incorrect.