对该程序中的用法感到很奇怪，请大家帮忙解释下！

[cmjauto]

大家好！
本人是初学者，学习版本是Ubuntu 12.04 LTS，最近练习网络编程时发现书中一个很奇怪的问题，无法解释为什么要这样。
代码不长的，其中问题的地方我已经注明了，代码在附件中，望大家下载下来看看。
我是按照书上到例子来的，还望各位朋友解释下，谢谢了！

15.1.c

(1.29 KiB) 已下载 76 次

[weidongxu]

看文档的话 h_addr 是宏，就是 h_addr_list[0]。为后向兼容定义的（估计早的时候没有addr_list，只有一个addr）。


http://msdn.microsoft.com/en-us/library ... 85%29.aspx


Syntax
C++


typedef struct hostent {
char FAR *h_name;
char FAR FAR **h_aliases;
short h_addrtype;
short h_length;
char FAR FAR **h_addr_list;
} HOSTENT, *PHOSTENT, FAR *LPHOSTENT;

Members

h_name

The official name of the host (PC). If using the DNS or similar resolution system, it is the Fully Qualified Domain Name (FQDN) that caused the server to return a reply. If using a local hosts file, it is the first entry after the IPv4 address.
h_aliases

A NULL-terminated array of alternate names.
h_addrtype

The type of address being returned.
h_length

The length, in bytes, of each address.
h_addr_list

A NULL-terminated list of addresses for the host. Addresses are returned in network byte order. The macro h_addr is defined to be h_addr_list[0] for compatibility with older software.

[cmjauto]

谢谢，明白了……

看文档的话 h_addr 是宏，就是 h_addr_list[0]。为后向兼容定义的（估计早的时候没有addr_list，只有一个addr）。


http://msdn.microsoft.com/en-us/library ... 85%29.aspx


Syntax
C++


typedef struct hostent {
char FAR *h_name;
char FAR FAR **h_aliases;
short h_addrtype;
short h_length;
char FAR FAR **h_addr_list;
} HOSTENT, *PHOSTENT, FAR *LPHOSTENT;

Members

h_name

The official name of the host (PC). If using the DNS or similar resolution system, it is the Fully Qualified Domain Name (FQDN) that caused the server to return a reply. If using a local hosts file, it is the first entry after the IPv4 address.
h_aliases

A NULL-terminated array of alternate names.
h_addrtype

The type of address being returned.
h_length

The length, in bytes, of each address.
h_addr_list

A NULL-terminated list of addresses for the host. Addresses are returned in network byte order. The macro h_addr is defined to be h_addr_list[0] for compatibility with older software.