(Original) how to capture the host ID of the C class IP address? (C/C ++) (c)

Abstract
My classmates asked me a little question. If it's still interesting, I just want to read it.

Introduction
Use environment: Visual C ++ 9.0/Visual Studio 2008

Get_c_class_ip_host_id.c/C

1 /*  
2 (C) oomusou 2008 Http://oomusou.cnblogs.com
3
4 Filename: get_c_class_ip_host_id.c
5 Compiler: Visual C ++ 9.0/Visual Studio 2008
6 Description: Demo How To Get host ID of C class IP.
7 Release: 07/30/2008 1.0
8 */
9 # Include < Stdio. h >
10 # Include < String . H >
11
12 Void Get_hostid ( Char   * S, Char   * T ){
13 Char   * U = Strrchr (S, ' . ' ) +   1 ;
14 While ( * T ++ = * U ++ );
15 }
16
17 Int Main (){
18 Char S [] =   " 140.113.23.145 " ;
19 Char T [ 4 ];
20 Get_hostid (S, T );
21 Printf ( " % S " , T );
22 }

Results

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