Average file size within a directory

To calculate the average file size within a directory on a Linux system, following command can be used:

ls -l | gawk '{sum += $5; n++;} END {print sum/n;}'

If you'd like to know the average size of some particular kind of files (like jpg files) then use the following:

ls -l *.jpg | gawk '{sum += $5; n++;} END {print sum/n;}'