As I recall the valid argument range is non-negative, plus the EOF value.
In practice, a `char` type actual argument needs to be cast to `unsigned char`.
Also, before calling such function, the program should have called setlocale( LC_ALL, "" ) (or set some other local).
184.108.40.206 13:05, 26 March 2012 (PDT)
- Such practice, if it exists, is misguided. However, the locale-specific nature of this function is important, updating... --Cubbi 18:38, 26 March 2012 (PDT)