Linux systems have a utility for changing file attributes on a Linux file system chattr, as well as lsattr that lists the attributes that are set currently. Those are not the -rwxrw-r---type permissions for owner/group/others, but lower level attributes, which have some interesting properties. Previously this functionality was

There are times when you need to execute a given task just once at a later time on a Unix-like operating system. cron might be the obvious choice for this, however, for a one-time task that would require either an elaborate schedule part (e.g. 05 04 12 08 05)