i made a script to update a lot of xml files. to save me some time. Ran it and it replaced all the the files with a 0kb file. The problem i was having is that I am using sed to change xml node <doc_root>. The problem with this is it has a / in the closing xml tag and the stuff inside will also have a bunch of / because it is a file path. so i am using sed and was hoping this would work:

Is my problem in the regex or is it because I am using $my_file > $my_file ? do i need to copy it to a temp file first the mv it to old file?
Or if its the regex can someone help with that
Here is the search string
Here is a typical replace string where the daomin.co.uk will be an argument from a for loop i.e $i

Please help before my boss gets angry with me