linux系统UDP的socket通信编程3

我刚开始接触linux下的socket编程，边抄边理解udp socket编程，我的疑问是server不指定IP地址，client的目标IP地址是127.0.0.1，这样就可以通信吗？在同一主机下是不是不能测试？如果server默认绑定本机的IP 地址，那么开启server后，在浏览器中输入127.0.0.1:(相应端口) 也可以得到数据？我的程序如下，没有跑起来，其实我觉得我不会测试，不知道本质所以会有细节漏掉。（使用的系统是ubuntu 11.10 ，编译器GCC ，分别在同一主机下的两个终端中运行生成的.out文件。）提前感谢大家的回答，不管多少，您的回答让一个初学者非常暖心～～

服务器程序

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#include<stdio.h> #include<netinet/in.h> #include<arpa/inet.h> #include<unistd.h> #include<sys/types.h> #include<sys/socket.h>   #define lport 4567   int main() {     int mysock,len;     struct sockaddr_in addr;     int i=0;     char msg[256];       int addr_len;       if((mysock=socket(AF_INET,SOCK_DGRAM,0))<0)     {         perror("error");         exit(1);     }     else     {         printf("socket created.\n");         printf("socket ID: %d\n",mysock);     }     addr_len=sizeof(struct sockaddr_in);     bzero(&addr,sizeof(addr));     addr.sin_family=AF_INET;     addr.sin_port=htons(lport);     addr.sin_addr.s_addr=htonl(INADDR_ANY);       if(bind(mysock,&addr,sizeof(addr))<0)     {         perror("connect");         exit(1);     }     else     {         printf("bind ok.\n");         printf("local port: %d\n",lport);     }     while(1)     {         bzero(msg,sizeof(msg));         len=recvfrom (mysock,msg,sizeof(msg),0,&addr,&addr_len);           printf("%d: ",i);         i++;         printf("message form: %s\n",inet_ntoa(addr.sin_addr));         printf("message: %s\n\n",msg);         sendto(mysock,msg,len,0,&addr,addr_len);     }     return 0; }

客户机程序：

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#include<stdio.h> #include<netinet/in.h> #include<arpa/inet.h> #include<unistd.h> #include<fcntl.h> #include<sys/stat.h> #include<sys/types.h> #include<sys/socket.h>   #define rport 4567 #define rip "127.0.0.1"   int main() {     int s,len;     struct sockaddr_in addr;     int addr_len;     char msg[256];     int i=0;       if((s=socket(AF_INET,SOCK_DGRAM,0))<0)     {         perror("error");         exit(1);     }     else     {         printf("socket created.\n");         printf("socket id: %d\n",s);         printf("romote ip: %s\n",rip);         printf("remote port: %d\n",rport);     }       len=sizeof(struct sockaddr_in);     bzero(&addr,sizeof(addr));     addr.sin_family=AF_INET;     addr.sin_port=htons(rport);     addr.sin_addr.s_addr=inet_addr(rip);       while(1)     {         bzero(msg,sizeof(msg));         len=read(STDIN_FILENO,msg,sizeof(msg));         sendto(s,msg,len,0,&addr,addr_len);         printf("\nInput message: %s\n",msg);         len=recvfrom(s,msg,sizeof(msg),0,&addr,&addr_len);           printf("%d :",i);         i++;         printf("received message: %s \n",msg);     }     return 0; }