delete all remote branches that have already been merged into master

gistfile1.txt

$ git branch -r --merged | 
  sed '/>|master/d;/origin/!d;s:origin/::' |
  xargs git push origin --delete

# I think this will work, but I don't know how to get git branch to show me that -> line

This shows me the -> line:
git branch -r --merged | grep '>'
The output is essentially:
origin/HEAD -> origin/main
(it also showed one branch with a long name that contains a '>')

Guessing https://stackoverflow.com/questions/6127328/how-can-i-delete-all-git-branches-which-have-been-merged is the place to go now. Pretty sure I made this gist before SO existed :)