Edit a file via a script yet maintain the osx tags

On OSX you can have tags which allows you to identify different categories of files. Here are two text files with different tags when viewed in Finder:

I have a large number of these files and have written a bash script to make several edits on these files. So, for instance I do:

$ sed 's/old text/new text/' file1.txt > /tmp/foo.txt
$ cp -p /tmp/foo.txt file1.txt

in which case I get the desired file content but loose the tags:

Question: How do I copy the tags from the original file to the edited file?