#include <stdio.h>
#include <stdarg.h>

/* The C Programming Language, 2nd Edition
 *
 * Exercise 7-4: Write a private version of `scanf` analagous to minprintf
 * from the previous section.
 *
 * Notes: Again, it doesn't specify which facilities, so we'll choose a few
 * of the more important ones:
 *
 *     d - decimal number
 *     s - string
 *     f - floating point number
 *
 * Then pass things off to scanf().
 */

void minscanf(char *fmt, ...) {
	va_list ap;
	char *p, *sval, *rval;
	int *ival;
	float *fval;
	va_start(ap, fmt);
	for (p = fmt; *p; p++) {
		if (*p != '%') {
			putchar(*p);
			continue;
		}
		switch (*++p) {
			case 'd':
				ival = va_arg(ap, int *);
				scanf("%d", ival);
				break;
			case 'f':
				fval = va_arg(ap, float *);
				scanf("%f", fval);
				break;
			case 's':
				sval = va_arg(ap, char *);
				scanf("%s", sval);
				break;
			default:
				putchar(*p);
				break;
		}
	}
	va_end(ap);
}

int main(int argc, char *argv[]) {
	printf("Enter a floating point number: ");
	float foo;
	minscanf("%f", &foo);
	printf("We got a %f...\n", foo);
	printf("Okay, and a regular number: ");
	int bar;
	minscanf("%d", &bar);
	printf("And you gave me %d\n...", bar);
	/* Interestingly, if your integer has a floating-point portion,
	 * it becomes the first string of minscanf()'s next call.
	 * This is peculiar and I'm not sure how to fix it.
	 */
	printf("Lastly, your first and last name, please: ");
	char baz[80];
	char biz[80];
	minscanf("%s %s", &baz, &biz);
	printf("Nice to meetcha, %s %s!\n", &*baz, &*biz);
	return 0;
}