Why 'fputc' use an INT as its parameter instead of CHAR?

Question

standard C lib:

int fputc(int c , FILE *stream);

And such behaviors occured many times, e.g:

    int putc(int c, FILE *stream);
    int putchar(int c);

why not use CHAR as it really is? If use INT is necessary, when should I use INT instead of CHAR?

Answer 1

I believe that it was simply to mirror the fgetc type functions which must be able to return any real character plus the EOF special character.

To do that, they needed an int type since a char isn't quite large enough.