chmod

More coffee, more tales of daft customers - Huw's this time, several years ago on a Unix helpline. There's a Unix command called chmod which is used to change the permissions on a file, e.g. to stop other people from reading/writing a file belonging to you. It also allows you to say whether or not a file is executable - you need to set the executable permission on a Perl script, for example, before you can actually run it.

Anyway, someone phoned in to say that, worried about the idea of people fiddling with file permissions, they had chmod-ed chmod so that it wasn't executable by anyone. Thus rendering it completely useless. They eventually had to send out a new copy on floppy disk.

This is exactly why I was always glad nobody ever gave me the root password...