재시민

///////CONCURRENT SERVER.c///////////
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

#define SIZE sizeof(struct sockaddr_in)

int main(void)
{
	int sockfd_listen;
	int sockfd_connect;
	int client_len;
	
	char buff[80];
	//struct sockaddr_in server = {AF_INET, 5000, INADDR_ANY};
	struct sockaddr_in server,client;
	// server, client 소켓 정의 	


	bzero(&server, sizeof(server));//server 에 자신의 크기만큼 0 으로 clear
	server.sin_family = AF_INET; //IPv4
	server.sin_port = 5000; // 포트 설정 
	server.sin_addr.s_addr = inet_addr("192.168.56.128");
	
	printf("Server IP %s, Server Port : %u\n",inet_ntoa(server.sin_addr), server.sin_port);
	
	///////////////SOCKET///////////////////
	printf("skcket()\n");
	sockfd_listen =socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); //sockfd_listen = 3
	if(sockfd_listen < 0)
		printf("socket error\n");
	else
		printf("client sock%d\n",sockfd_listen);
	///////////////SOCKET///////////////////

	///////////////BIND/////////////////////
	//1. IPv4 address
	printf("bind()\n");
	if(bind(sockfd_listen, (struct sockaddr *)&server, SIZE))
		printf("bind error \n");
	///////////////BIND/////////////////////	

 	///////////////LISTEN///////////////////
	printf("listen()\n");
   	if(listen(sockfd_listen,5) == -1)
		printf("listen error \n");
 	///////////////LISTEN///////////////////

	
	while(1){
		bzero(&client, sizeof(client));
		client_len= sizeof(client);
		
 	///////////////ACCEPT////////////////////
		printf("wating for client\n");
		sockfd_connect = accept(sockfd_listen, (struct sockaddr *)&client, &client_len);
		//sockfd_connect = 4
		
		if(sockfd_connect < 0 )
			printf("accept error\n");
		else
			printf("sockfd connect %d\n",sockfd_connect);
		printf("accepted\n");
		printf("SERVER : Client IP : %s, Client Port : %u \n",inet_ntoa(client.sin_addr), 			ntohs(client.sin_port));
 	///////////////ACCEPT////////////////////
	
 	///////////////ACCEPT////////////////////

	//client 와 ACCEPT 하면 fork 하여 자식 프로세스와 통신 
		if(fork() == 0) { //child process
		
		//close
			close(sockfd_listen); // 3 close (parent)
			while(1){
				bzero(buff,sizeof(buff));
				recv(sockfd_connect, buff, sizeof(buff), 0 );
				printf("Server recv %s \n",buff);
				
				//"quit" exit
				if(strcmp(buff, "quit") == 0){//when BUFFER is a "quit" 
					printf("client exit \n");
					close(sockfd_connect); // 4 child process close
					exit(0); // child process exit
				}
				else	{	
					//fgets(buff, sizeof(buff), stdin); // can't chat is child , buff= hello --> "hello:server"
					strcat(buff, ":::SERVER"); // BUFFER 에 :SERVER 를 달아서 server 가 메시지를 받음을 확인
					send(sockfd_connect, buff, strlen(buff),0);
					continue; // goto 67 line (while)
				}
			}

			close(sockfd_connect); // 4
			exit(0); // child process exit
			
		}//end child
		
		//paraent process
		printf("close() sockfd_connect = %d\n", sockfd_connect); //4s
		close(sockfd_connect);

	}//end while
	
	//close(sockfd_listen);	
}

Server 의 특징 

• Client 코드를 직접 배포

///////////CILENT.c///////////

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

#define SIZE sizeof(struct sockaddr_in)

int main(void)
{
	int sockfd;
	//char send_c, recv_c;
	char message[80];
	
	struct sockaddr_in server ;
	
	bzero(&server, sizeof(server));//0 clear
	server.sin_family = AF_INET; //IPv4
	server.sin_port = 5000;
	//server.sin_addr = INADDR_ANY;
	server.sin_addr.s_addr = inet_addr("192.168.56.128");
	printf("Client IP %s, Client Port : %u\n",inet_ntoa(server.sin_addr), server.sin_port);
	
/////////SOCKET//////////
	printf("skcket()\n");
	sockfd =socket(AF_INET, SOCK_STREAM, 0);
/////////SOCKET//////////
	
/////////CONNECT//////////
	printf("connect()\n");
	connect(sockfd, (struct sockaddr *)&server, SIZE);
/////////CONNECT//////////

/////////SEND_LOOP////////
	while(1){//send -> rcv
		printf("client message: ");
		fgets(message, sizeof(message), stdin);
		send(sockfd,message,strlen(message)-1,0);//fgets include 'enter' space so, -1
		
		bzero(message,sizeof(message));
		recv(sockfd, message, sizeof(message), 0);
		printf("client recv: %s \n",message);
	}
/////////SEND_LOOP////////	
	
	printf("close()\n");
	close(sockfd);
	
}

//////////FORK_PRACTICE/////////

#include <stdio.h>
#include <sys/type.h>
#include <unistd.h>

int main(void){

	pid_t pid;
//pid 선언
	
	pid=fork();
// fork 하여 자식 프로세스 생성
	
	if(pid>0){// 부모 프로세스 일때
		printf("parent process pid : %d \n",getpid());
		printf("parent process ppid : %d \n",getppid());
		printf("parent process child id : %d \n",pid);
		sleep(30);
	else if(pid==0){//자식 프로세스 일때
		printf("child process pid : %d \n",getpid());
		printf("child process ppid : %d \n",getppid());
	}
	else{
		prinf("fork error\n");
	}
}