file_permissions

https://github.com/godobject/file_permissions

FilePermissions is a Ruby library providing an object representation of the file permission bits in POSIX systems. It can handle the generic read, write and execute permissions, as well as the setuid, setgid and sticky flags. Permission sets can be read from file system objects, parsed from typical string representations or simply defined by their numeric representation. They can then be manipulated through binary logic operators and written back to file system objects.