socket通信基本流程

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>

int serverPort = 8000;

int main()
{
struct sockaddr_in listeningSockAddr;
struct sockaddr_in clientSockAddr;
int clientAddrSize;

int listeningSock;
int comunicateSock;

char clientStr[100],str1[20],str2[20],str3[20];
char toClientBuf[100];
int clientStrLen,toClientBufLen;
float c;
//建立socket
listeningSock =socket(AF_INET,SOCK_STREAM,0);
if(listeningSock == -1){
perror("socket failed");
exit(1);
}

//建立IPv4地址
bzero(&listeningSockAddr,sizeof(listeningSockAddr));
listeningSockAddr.sin_family = AF_INET;
listeningSockAddr.sin_addr.s_addr = htonl(INADDR_ANY);//监听所有ip地址
listeningSockAddr.sin_port = htons(serverPort);

//绑定socket
if(bind(listeningSock,(struct sockaddr *)&listeningSockAddr,sizeof(listeningSockAddr)) == -1){
perror("bind failed");
exit(1);
}

//监听client端
if(listen(listeningSock,20) == -1){
perror("call to listen");
exit(1);
}

while(1){
printf("Accepting connections ... \n");
//接受Client端连接
comunicateSock = accept(listeningSock,(struct sockaddr*)&clientSockAddr,&clientAddrSize);//如果不再乎客户端的ip，那第二，三个参数可设为NULL

if(comunicateSock == -1){
perror("accept failed");
exit(1);
}

printf("客户端的ip：%s,端口号：%d\n",inet_ntoa(clientSockAddr.sin_addr),clientSockAddr.sin_port);

//接收client端传来的信息
clientStrLen = recv(comunicateSock,clientStr,100,0);
clientStr[clientStrLen] = '\0';

printf("Received %d characters from client,the string is:%s\n",clientStrLen,clientStr);

//分析处理Client端传来的信息
if(clientStrLen > 0){
strcpy(str1,strtok(clientStr," "));
printf("第1个字符串为：%s\n",str1);
strcpy(str2,strtok(NULL," "));
printf("第2个字符串为：%s\n",str2);
strcpy(str3,strtok(NULL," "));
printf("第3个字符串为：%s\n",str3);
c = atof(str3)*1.05;
sprintf(toClientBuf,"商 品 号 为  %s \n商 品 名 为  %s\n含 税 价 为  %.2f\n",str1,str2,c);
}
//将处理过的信息返回给Client端
toClientBufLen = strlen(toClientBuf);
if(send(comunicateSock,toClientBuf,toClientBufLen,0) == -1){
perror("call to send");
exit(1);
}
//关闭与Client端的连接
close(comunicateSock);
}
return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

int serverPort = 8000;

int main(int argc,char *argv[])
{
struct sockaddr_in serverSock;
int bindingServerAddrSock;
char buf[8192];
char *str = "A001 电视机 20000.00";

printf("使用方法:client 字符串\n");

if(argc < 2){
printf("argc < 2,使用默认字符串\n");
}
else{
str = argv[1];
}

/*建立Server IPv4地址 */
bzero(&serverSock,sizeof(serverSock));
serverSock.sin_family = AF_INET;
serverSock.sin_addr.s_addr = inet_addr("127.0.0.1");
serverSock.sin_port = htons(serverPort);

/* 建立Socket */
bindingServerAddrSock = socket(AF_INET,SOCK_STREAM,0);
if(bindingServerAddrSock == -1){
perror("socket failed");
exit(1);
}

/*连接Server */
if(connect(bindingServerAddrSock,(void *)&serverSock,sizeof(serverSock)) == -1){
perror("connect failed");
exit(1);
}
/*将str字符串传给 Server */
printf("Sending message %s to server ...\n",str);

if(send(bindingServerAddrSock,str,strlen(str),0) == -1){
perror("error in sending\n");
exit(1);
}

/*接收Server回传的信息 */
if(recv(bindingServerAddrSock,buf,8192,0) == -1){
perror("Error in receiving");
exit(1);
}

printf("\nResponse these from server :%s\n",buf);
close(bindingServerAddrSock);
return 0;
}