unquote scripts/testscript.txt
unquote testscript-new.txt
testscript -update scripts
cmp scripts/testscript.txt testscript-new.txt

-- scripts/testscript.txt --
>fprintargs stderr right
>cmp stderr expect
>
>-- expect --
>wrong
-- testscript-new.txt --
>fprintargs stderr right
>cmp stderr expect
>
>-- expect --
>right