Find files in /usr/local larger than 3 KB and smaller than 5 KB, copy them...

Solution:

mkdir -p /root/d1

find /usr/local -type f -size +3k -size -5k -exec cp -rvf {} /root/d1/ \;

chmod g+s /root/d1

ls -ld /root/d1

Detailed Explanation:

-size +3k means greater than 3 KB.

-size -5k means less than 5 KB.

chmod g+s sets the SGID bit on the directory.

SGID on a directory causes new files created there to inherit the directory’s group.