printf.c

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

void nealprintf(char *fmt, ...)
{
	va_list ap;
	char *p, *sval;
	int ival;
	double dval;

	va_start(ap, fmt);
	for(p = fmt ; *p ; p++){
		if(*p != '%'){
			putchar(*p);
			continue;
		}
		switch(*++p){
			case 'd':
				ival = va_arg(ap, int);
				printf("%d", ival);
				break;
			case 'f':
				dval = va_arg(ap, double);
				printf("%f", dval);
				break;
			case 's':
				for(sval = va_arg(ap, char *) ; *sval ; sval++)
					putchar(*sval);
				break;
			default:
				putchar(*p);
				break;
		}
	}
	va_end(ap);
}


int main(int argc, char **argv)
{
	int i = 10;
	char *str = "will win!!";
	nealprintf("%d %s\n", i, str);

	return 0;
}