#define MAXLENGTH 128

/* double_int is a function to double any integer value */

int double_int(int x) {
	int y = 2 * x;
	return y;
}

/* double_str is a function to double any char * value */

char * double_str(char * s) {
	char t[MAXLENGTH];
	strcpy(t, s);
	strcat(t, s);
	return t;
}