//Declaration: int isupper(int ch); //Return: returns nonzero if ch is an uppercase letter; otherwise zero is returned. #include <ctype.h> #include <stdio.h> int main(void) { char ch; for(;;) { ch = getchar(); if(ch == '.'){ break; } if(isupper(ch)){ printf("%c is uppercase\n", ch); } } return 0; } /* d s a w C C is uppercase . */