linux手册上的说明 If size is 0, then malloc() returns either NULL, or a unique pointer value that can later be successfully passed to free(). 意思是如果传入的size为0,则返回NULL或者一个指针,该指针可以正确的被free调用 那么该指针到底指向什么呢? glibc的实现 /malloc/malloc.c 492行 malloc(size_t n) If n is
[基础知识说明] 结构原型: /* * Interface request structure used for socket * ioctl's. All interface ioctl's must have parameter * definitions which begin with ifr_name. The * remainder may be interface specific. */ struct ifreq {#define IFHWADDRLEN 6 union {