I need help to do something like the the description below. I am very new to perl and need help with directory handling.

1. dir_source has around 20 sub directors (say sub1, sub2...sub20) 2. under a new path (say source_dir), need to create a new dir by name "dir_parent_sub1" 3. copy all files from dir_parent/sub1 dir to the new dir, source_dir/dir_parent_sub1 3. cd to source_dir/dir_parent_sub1 4. cp name.txt to name.txt.orig 5. go up one level to source_dir and change the permissions on the dir_parent_sub1 using chmod -R 770 dir_parent_sub1 6. repeat the steps 2-5 for all directories under dir_parent