The Ghost Directory

Simulate a filesystem path simplified with a ghost operator '^'. A path is a sequence of directory names separated by '/'. The '.' operator does nothing. The '..' operator removes the previous directory. The '^' operator is a 'ghost' delete: it removes the PREVIOUS TWO directories from the path. If there aren't enough directories to remove for '..' or '^', simply clear the path as much as possible. Example: Input: 'usr/lib/config/^/bin' 1. usr, lib, config 2. '^' encounter: remove 'config' and 'lib' 3. Result: 'usr/bin' Output: 'usr/bin'