我永远无法理解如何用C打印unsigned long个数据类型.
假设unsigned_foo是unsigned long，那么我try :
printf("%lu\n", unsigned_foo)printf("%du\n", unsigned_foo)printf("%ud\n", unsigned_foo)-
printf("%ll\n", unsigned_foo)个 -
printf("%ld\n", unsigned_foo)个 printf("%dl\n", unsigned_foo)
他们打印的都是-123123123号，而不是我的unsigned long号.