Linux下C语言实现TCP Socket编程

TCP协议：

TCP/IP(Transmission Control Protocol/Internet Protocol) 即传输控制协议/网间协议，是一种面向连接（连接导向）的、可靠的、基于字节流的运输层（Transport layer）通信协议。

TCP服务器端和客户端流程：

具体函数：

具体实现：

服务器端：

ser.c

#include<stdio.h>#include<stdlib.h>#include<unistd.h>#include<string.h>#include<assert.h>#include<netinet/in.h>#include<sys/types.h>#include<sys/socket.h>#include<arpa/inet.h>int main(){int sockfd=socket(AF_INET,SOCK_STREAM,0);assert(sockfd!=-1);struct sockaddr_in ser,cli;memset(&ser,0,sizeof(ser));ser.sin_family=AF_INET;ser.sin_port=htons(6000);ser.sin_addr.s_addr=inet_addr("127.0.0.1");int res=bind(sockfd,(struct sockaddr*)&ser,sizeof(ser));assetr(res!=-1);listen(sockfd,5);while(1){int len=sizeof(cli);int c=accept(sockfd,(struct sockaddr*)&cli,&len);if(c<0){perror("error\n");continue;}while(1){char recvbuf[128]={0};int n=recv(c,recvbuf,127,0);if(n<=0){printf("one client over\n");break;}printf("%d:%s\n",c,recvbuf);send(c,"OK",2,0);}close(c);}close(sockfd);}

客户端：

cli.c

#include<stdio.h>#include<stdlib.h>#include<unistd.h>#include<assert.h>#include<string.h>#include<netinet/in.h>#include<sys/types.h>#include<sys/socket.h>#include<arpa/inet.h>int main(){int sockfd=socket(AF_INET,SOCK_STREAM,0);assert(sockfd!=-1);struct sockaddr_in ser,cli;memset(&ser,0,sizeof(ser));ser.sin_family=AF_INET;ser.sin_port=htons(6000);ser.sin_addr.s_addr=inet_addr("127.0.0.1");int res=connect(sockfd,(struct sockaddr*)&ser,sizeof(ser));assert(res!=-1);while(1){printf("please input:");fflush(stdout);char buff[128]={0};fgets(buff,128,stdin);buff[strlen(buff)-1]=0;if(strcmp(buff,"end")==0){break;}send(sockfd,buff,strlen(buff),0);char recvbuff[128]={0};recv(sockfd,recvbuff,127,0);printf("%s\n",recvbuff);}close(sockfd);}