permission denied :(
 

I was trying to move a file across to another directory
using the command
mv myfile /usr
i got the message
mv: cannot move `copy' to `/usr/copy': Permission denied

why am i getting that message?

if you dont own either the file or the directory you will get that error.

ls -l and see who is the owner of the file, then do the same thing for that dir.

worst case, su - and move it as root.

You need to be root to write to /usr; that's the most obvious explanation. If you were root, check the permissions on the file your trying to move; it might be read only, in which case you will have to change the permissions using chmod before you are allowed to move the file, even as root.