do not delete a file created by root user in the other users folder

view story

http://stackoverflow.com – I have a user called "sam" and the home directory of sam is /home/sam Now as a root user i have to keep some files in /home/sam/Desktop directory . and sam should have only read and execute permission he should not delete that file. not the desktop file will be a soft link of /usr/share/application steps i have tried : log in as root cd /home/sam/Desktop echo "test not delete file" > /usr/share/application/abc.txt ln -s /usr/share/application/abc.txt /home/sam/Desktop/abc.txt exit log in as sam rm /home/sam/Desktop/abc.txt Do you want to delete write protected file? y delete success no (HowTos)