Bulk rename folders?

Question

linux

There are many files and folders:
/home/user/dir1/dir2/file1
...
How can I rename them so that there is one character before the folder name, namely:
/home/user/0dir1/0dir2/file1
?

Answer 1

for i in $(find /home/user -type d | tac); do mv $i $(echo $i | perl -pe 's/\/([^\/]*?)$/\/0\1/') 2> /dev/null; done