Parses the specified text string and converts it to the binary
    representation for an access control entry (ACE).

    Format

      SYS$PARSE_ACL  aclstr ,aclent ,[errpos] ,[accnam] ,[nullarg]

    C Prototype

      int sys$parse_acl  (void *aclstr, void *aclent, unsigned

                         short int *errpos, void *accnam, int

                         (*routin)(void));