"""
converts a permission mask in symbolic format (ex.: drwxr-xr-x) to a
string that's usable in a chmod command

ex.: chmod u=rwx,g=,o= ~/myscripts/convert_mask.py

Created by Bert Heymans on 2006-10-12. This code is public domain.
"""
class SymbolicPermission:
       
        def __init__(self, symbolicString):
        """
                        split up into user, group, other
                """
                self.user = symbolicString[1:4]
                self.group = symbolicString[4:7]
                self.other = symbolicString[7:10]
                pass
       
        def toUsableString(self):
        """
                        format to a usable string, that can be used in a chmod command
                        ex.: u=rwx,g=,o=
                """
                def replaceAll(perm):
                        perm = perm.replace('-','')
                        perm = perm.replace('s','sx')
                        perm = perm.replace('t','tx')
                        # don't reverse order of S and s replacement (obvious)
                        perm = perm.replace('S','s')
                        perm = perm.replace('T','t')
                        return perm
                self.user = replaceAll(self.user)
                self.group = replaceAll(self.group)
                self.other = replaceAll(self.other)
                return "u=%s,g=%s,o=%s" % (self.user, self.group, self.other)