That's probably because you used BSD sed. Running it on my BSD sed also gives an error, presumably because it thinks the `}` is a part of the label in `binput}`.
However it works fine in GNU sed, and now that you mention it, GNU sed's extensions were not used, like the `-z` flag to slurp all input in one "line" to avoid `:input;$!{N;binput}`.
However it works fine in GNU sed, and now that you mention it, GNU sed's extensions were not used, like the `-z` flag to slurp all input in one "line" to avoid `:input;$!{N;binput}`.