Linux中获取本机网络信息的几个函数及应用

#include <stdio.h>
#include <netdb.h>
#include <sys/utsname.h>
main()
{
        printf("============获取host信息====================
");
        struct hostent *ent;
        /*打开主机配置数据文件*/
        sethostent(1);
        while(1)
        {
                ent=gethostent();
                if(ent==0)break;
                printf("主机名:%s	",ent->h_name);
                printf("IP地址：%hhu.%hhu.%hhu.%hhu	",ent->h_addr[0],ent->h_addr[1],ent->h_addr[2],ent->h_addr[3]);
                printf("别名：%s
",ent->h_aliases[0]);
        }
        endhostent();
        //获取本机信息
        printf("==============获取本机信息==================
");
        struct protoent *ent2;
        struct utsname name;
        ent2=getprotobyname("tcp");
        printf("proto:%d
",ent2->p_proto);
        uname(&name);
        printf("machine:%s
",name.machine);
        printf("nodename:%s
",name.nodename);
        printf("sysname:%s
",name.sysname);
        //通过域名获取IP
        printf("========通过域名获取IP=====================
");
        struct hostent *ent3;
        ent3=gethostbyname("www.baidu.com");
        printf("%hhu.%hhu.%hhu.%hhu
",ent3->h_addr_list[0][0],ent3->h_addr_list[0][1],ent3->h_addr_list[0][2],ent3->h_addr_list[0][3]);
}