#include <stdarg.h>
#include "string.h"

int sprintf(char *str, const char *format, ...) {
	va_list argp;

	va_start(argp, format);
	int rval = vsprintf(str, format, argp);
	va_end(argp);

	return rval;
}

int vsprintf(char *str, const char *format, va_list argp) {
	const char *p;
	int i;
	char *s;

	for (p = format; *p != '\0'; p++) {
		if (*p != '%') {
			*str++ = *p;
		} else {
			switch (*++p) {
				case 'c':
					i = va_arg(argp, int);
					*str++ = (char)i;
					break;
				case 's':
					s = va_arg(argp, char *);
					while (*str++ = *s++)
						;
					str--;
					break;
				case 'd':
					s = itoa(va_arg(argp, int));
					while (*str++ = *s++)
						;
					str--;
					break;
				case 'x':
					s = itoa_base(va_arg(argp, unsigned int), 16);
					while (*str++ = *s++)
						;
					str--;
					break;
				case '%':
					*str++ = '%';
					break;
			}
		}
	}

	*str = '\0';
	
	return 0;
}