Code: #include #include #include #include #define COLS 80 #define ROWS 23 /* Function prototypes */ int init(char); int display(); int drawPt(char, int, int); int drawRect(char, int, int, int, int); int drawLine(char, int, int, int, int); int fill(char, int, int); int saveFile(char* filename); char buffer [80]; FILE *input, *output; /* Global variables */ char screen[COLS][ROWS]; int main(void){ input= ...