File Space

df -k gives the amount of disk space (in kilobytes) used up in all the disks.

df -m gives the amount of disk space (in megabytes) used up in all the disks.

If the output from the above is confusing, just type:

df -h . which will give you the disk usage (including spare capacity) on the disk partition where you are currently sitting in more human readable units.

du -h file gives the amount of disk space of file (in more human readable units) where file can be a filename or directory