Variadic functions

#include <stdarg.h>
#include <stdio.h>
void simple_printf(const char* fmt, ...)
{
    va_list args;
    for (va_start(args, fmt); *fmt != '\0'; ++fmt)
    {
        switch(*fmt)
        {
            case 'd':
            {
                int i = va_arg(args, int);
                printf("%d\n", i);
                break;
            }
            case 'c':
            {
                // A 'char' variable will be promoted to 'int'
                // A character literal in C is already 'int' by itself
                int c = va_arg(args, int);
                printf("%c\n", c);
                break;
            }
            case 'f':
            {
                double d = va_arg(args, double);
                printf("%f\n", d);
                break;
            }
            default:
                puts("Unknown formatter!");
                goto END;
        }
    }
END:
    va_end(args);
}
int main(void)
{
    simple_printf("dcff", 3, 'a', 1.969, 42.5);
}