sock_addr和sock_addr_in是有区别的,实际上,它们都在系统库的头文件里面,为了方便起见,我把它们请出来,这样才知道它们的异同,看程序:
#include <stdio.h>
#include <string.h>
struct in_addr {
union {
struct { unsigned char s_b1,s_b2,s_b3,s_b4; } S_un_b;
struct { unsigned short s_w1,s_w2; } S_un_w;
unsigned long S_addr;
} S_un;
#define s_addr S_un.S_addr
/* can be used for most tcp & ip code */
#define s_host S_un.S_un_b.s_b2
/* host on imp */
#define s_net S_un.S_un_b.s_b1
/* network */
#define s_imp S_un.S_un_w.s_w2
/* imp */
#define s_impno S_un.S_un_b.s_b4
/* imp # */
#define s_lh S_un.S_un_b.s_b3
/* logical host */
};
struct sockaddr_in {
short sin_family;
unsigned short sin_port;
struct in_addr sin_addr;
char sin_zero[8];
};
struct sockaddr {
unsigned short sa_family; /* address family */
char sa_data[14]; /* up to 14 bytes of direct address */
};
int main()
{
struct sockaddr_in A;
struct sockaddr *pB = (struct sockaddr *)(&A);
A.sin_family = 0x1234;
A.sin_port = 0x4321;
A.sin_addr.S_un.S_addr = 0xaabbccdd;
memset(A.sin_zero, 0, sizeof(A.sin_zero));
strncpy(A.sin_zero, "1234567", 8 - 1);
printf("%0x, %s\n", pB->sa_family, pB->sa_data);
return 0;
}
看结果:
1234, !C萏华1234567
多的就不解释了。