I was trying to copy a directory, and I kept getting a cryptic error:
cp: omitting directory `/var/log'
The copy (cp) command only works for files. To copy a directory, you need to use the -r recursive flag:
cp -r /var/log backup/log_dir_backup
In this case, I was trying to copy the log directory to make a quick and dirty backup. This failed with a long list of “cannot open ‘file…’ for reading: Permission denied” errors. Naturally I needed to us sudu:
sudo cp -r /var/log backup/log_dir_backup
Now it worked.
The move mv command works the same way. You need to use the -r recursive flag to mv a directory:
mv -r log_dir_backup log_backup_yyyymmdd