[gpanders]

That works when specifying a backup extension, but not if you don’t want to create a backup file.

    sed -i ‘’ ...

works on BSD sed but not GNU. Meanwhile:

    sed -i’’ ...
    sed -i ...

both work on GNU but not BSD.

[bewuethr]

Well, yes, you can't use it without creating a backup file, but it uses "-i" and is portable.