It isn't designed that way, no. This is simply an internal choice made by C library implementors, and one implementation choice fares very badly in this situat

It isn't designed that way, no. This is simply an internal choice made by C library implementors, and one implementation choice fares very badly in this situation, as the strings grow long. The other choice is pretty much immune to long strings in these scenarios. You cannot infer from this an intended usage of sscanf(), because this issue isn't part of the interface contract, just an effect of a particular implementation.