Avoiding Errors

Many users report frustration with the Unix operating system at one time or another, frequently because of their own doing. A feature of the Unix operating system that many users' love when they're working well and hate after a late-night session is how very few commands ask for confirmation. When a user is awake and functioning, they rarely think about this, and it is an assest since it let's them work smoother.

However, there are some disadvantages. rm and mv never ask for confirmation and this frequently leads to problems. Thus, let's go through a small list that might help you avoid total disaster:

• Keep backups! This applies especially to the one user system--all system adminstrators should make regular backups of their system! Once a week is good enough to salvage many files. See the The System Adminstrator's Guide for more information.
• Individual user's should keep there own backups, if possible. If you use more than one system regularly, try to keep updated copies of all your files on each of the systems. If you have access to a floppy drive, you might want to make backups onto floppies of your critical material. At worst, keep additional copies of your most important material lying around your account in a seperate directory!
• Think about commands, especially ``destructive'' ones like mv, rm, and cp before you act. You also have to be careful with redirection (>)--it'll overwrite your files when you aren't paying attention. Even the most harmless of commands can become sinister:

  

  can easily become disaster:

  

• The author also recommends, from his personal experience, not to do file maintanence late at night. Does you directory structure look a little messy at 1:32am? Let it stay--a little mess never hurt a computer.
• Keep track of your present directory. Sometimes, the prompt you're using doesn't display what directory you are working in, and danger strikes. It is a sad thing to read a post on comp.unix.admin about a root user who was in / instead of /tmp! For example:

  

  The above series of commands would make the user very unhappy, seeing how they have just removed the password file for their system. Without it, people can't login!