tcp套接字编程

Posted 2021-07-24 吾乃世间奇才

操作系统：fedora/linux 34
涉及知识：
1：tcp连接过程
2：线程创建
3：文件读写
4：信号

server.c

#include <pthread.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>

#define SPORT	50000
#define SIP	"192.168.1.12"
#define MAX_BACKLOG 50
#define MY_MASSAGE_MAX 1024

int acc_fd;

void *read_pfun(void *arg)
{
	int fd	=	*((int*)arg);
	char message[MY_MASSAGE_MAX];
	while(1)
	{
		memset(message, 0, sizeof(message));
		if(read(fd, message, sizeof(message))  >	0)
			printf("\\nYour recevie message is :%s\\n", message);
	}

}

void close_fun(int signo)
{
        if(SIGINT == signo)
        {
                close(acc_fd); //shutdown(acc_fd)
                exit(0);
        }
}



int main(int argc, char *argv[])
{
	char send_message[MY_MASSAGE_MAX];

	signal(SIGINT, close_fun);

	int sfd	=	socket(AF_INET, SOCK_STREAM, 0); 
	if(sfd == -1)
		perror(argv[0]);

	struct sockaddr_in server_message;
	server_message.sin_family		=	AF_INET;
	server_message.sin_port			=	htons(SPORT);
	server_message.sin_addr.s_addr	=	inet_addr(SIP);

	if(	bind(sfd, (struct sockaddr *)&server_message, sizeof(server_message)) == -1	)
		perror(argv[0]);

	if((listen(sfd, MAX_BACKLOG)) == -1)
		perror(argv[0]);

	struct sockaddr_in client_message;
	int addrlen	=	sizeof(client_message);
	
	if((acc_fd 	= accept(sfd, (struct sockaddr*)&client_message,&addrlen)) == -1) 
		perror(argv[0]);
	printf("the client port is %d, the client ip is %s", ntohs(client_message.sin_port), inet_ntoa(client_message.sin_addr));

	pthread_t tid;
	pthread_create(&tid, NULL, read_pfun, &acc_fd);

	while(1)
	{
		memset(send_message, 0, sizeof(send_message));
		printf("Enter the message to send the your friend:");
		scanf("%s", send_message);
		write(acc_fd, send_message,sizeof(send_message));
	}
	return 0;
}

client.c

#include <signal.h>
#include <string.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>

#define MY_MESSAGE_SIZE_MAX 1024
#define SPORT  50000
#define SIP "192.168.1.12"


int fd;

void *read_func(void *parg)
{
	int cfd	=	*((int*)parg);
	char recv_message[MY_MESSAGE_SIZE_MAX];
	while(1)
	{
		memset(recv_message, 0, sizeof(recv_message));
	if( read(cfd, recv_message,MY_MESSAGE_SIZE_MAX) > 0)
		printf("\\nYou receive message is %s\\n", recv_message);
	}
}

void close_fun(int signo)
{
	if(SIGINT == signo)
	{
		close(fd);//shutdonw(fd)
		exit(0);
	}
}

int main(int argc, char * argv[])
{

	signal(SIGINT, close_fun);
	char send_message[MY_MESSAGE_SIZE_MAX];

	fd	=	socket(AF_INET, SOCK_STREAM, 0);
	if(fd == -1)
	perror(argv[0]);

	struct sockaddr_in client_message;
	client_message.sin_family	=	AF_INET;
	client_message.sin_port		=	htons(SPORT);
	client_message.sin_addr.s_addr	=	inet_addr(SIP);

	if( (connect(fd, (struct sockaddr *)&client_message, sizeof(client_message))) == -1)
			perror(argv[0]);

	pthread_t tid;
	pthread_create(&tid, NULL, read_func, (void*)&fd);

	while(1)
	{
		memset(send_message, 0, MY_MESSAGE_SIZE_MAX);
		printf("Enter the send message:");
		scanf("%s", send_message);

		if(write(fd, (void*)send_message, MY_MESSAGE_SIZE_MAX) == -1)
			perror(argv[0]);

	}

}

编译
gcc server.c -o s -pthread
gcc client.c -o c -pthread

运行：
打开两个终端：
先 ./s 再 ./c

然后./s窗口会打印客户端的ip和端口
s窗口输入信息，c窗口能打印，c窗口同理