The "workaround" to get piping to work is not cross-platform.

• https://stackoverflow.com/questions/7395157/windows-equivalent-to-dev-stdin

I highly recommend handling it like kubectl and other tools where you can pass in - as file name which triggers reading from stdin.

So something like echo "asdf" | sops - or echo "asdf" | sops -f -

Is this something you would accept a PR for?