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.