6월13일 채팅, 실습

실습4:

교재 6.동시처리 챕터에서 페이지 68-67사이 select 이용한 채팅 서버 -클라이언트 구현

 

chatting_server.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#define BUFSIZE 100
int main(int argc, char **argv)
{
    int serv_sock;
    struct sockaddr_in serv_addr;
    fd_set reads, temps;
    int fd_max;
    char message[BUFSIZE];
    int str_len;
    struct timeval timeout;
    if (argc != 2)
    {
        printf("Usage : %s <port>\n", argv[0]);
        return -1;
    }
    int so_reuseaddr = 1;
    int state = setsockopt(serv_sock, SOL_SOCKET, SO_REUSEADDR,
        (void *)&so_reuseaddr, sizeof(so_reuseaddr));
    serv_sock = socket(PF_INET, SOCK_STREAM, 0);
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(atoi(argv[1]));
    if (bind(serv_sock, (struct sockaddr *)&serv_addr,
        sizeof(serv_addr)) == -1)
    {
        perror("bind() error");
        return -1;
    }
    if (listen(serv_sock, 5) == -1)
    {
        perror("linsten() error");
        return -1;
    }
    FD_ZERO(&reads);
    FD_SET(serv_sock, &reads); // 파일 디스크립터 설정(서버)
    fd_max = serv_sock;
    while (1)
    { // 무한 루프
        int clnt_fd, fd, str_len;
        int clnt_sock, clnt_len;
        struct sockaddr_in clnt_addr;
        temps = reads; // select 함수 변화가 생긴 디스크립터를
                       // 제외한 나머지 비트들을 0으로 초기화
        timeout.tv_sec = 5; // 초 단위 설정
        timeout.tv_usec = 0; // 마이크로 초 단위 설정
        if (select(fd_max + 1, &temps, 0, 0, &timeout) == -1)
        {
            perror("select() error");
            return -1;
        }
        for (fd = 0; fd < fd_max + 1; fd++)
        {
            if (FD_ISSET(fd, &temps))
            {
                if (fd == serv_sock)
                {
                    clnt_len = sizeof(clnt_addr);
                    clnt_sock = accept(serv_sock,
                        (struct sockaddr *)&clnt_addr, &clnt_len);
                    FD_SET(clnt_sock, &reads);
                    if (fd_max < clnt_sock)
                        fd_max = clnt_sock;
                    printf("클라이언트 연결 : FD(%d) \n", clnt_sock);
                }
                else
                {
                    str_len = read(fd, message, BUFSIZE);
                    if (str_len == 0)
                    {
                        FD_CLR(fd, &reads);
                        close(fd);
                        printf("클라이언트 종료 : FD(%d)\n", fd);
                    }
                    else
                    {
                        for (clnt_fd = serv_sock + 1; clnt_fd < fd_max +
                            1; clnt_fd++)
                            write(clnt_fd, message, str_len);
                    }
                }
            }
        }
    }
    return 0;
}
 

 

 

 

chatting_client.c

#include <stdio.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <string.h>
#define MAXLINE 512
#define MAX_SOCK 128
char name[10];
int main(int argc, char *argv[])
{
    int s;
    struct sockaddr_in server_addr;
    int n, pid;
    int maxfdp1;
    fd_set read_fds;
    char line[MAXLINE];
    char message[MAXLINE + 1];
    if (argc != 4)
    {
        printf("사용법 : %s sever_IP port name \n", argv[0]);
        return -1;
    }
    sprintf(name, "[%s]", argv[3]);
    if ((s = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        printf("Client : Can't open stream socket.\n");
        return -1;
    }
    bzero((char *)&server_addr, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr(argv[1]);
    server_addr.sin_port = htons(atoi(argv[2]));
    if (connect(s, (struct sockaddr *)&server_addr, sizeof(server_addr))
        < 0)
    {
        printf("Client : Can't connect to server.\n");
        return -1;
    }
    else
    {
        printf("서버에 접속되었습니다. \n");
    }
    maxfdp1 = s + 1;
    FD_ZERO(&read_fds);
    while (1)
    {
        FD_SET(0, &read_fds);
        FD_SET(s, &read_fds);
        if (select(maxfdp1, &read_fds, (fd_set *)0,
            (fd_set *)0, (struct timeval *)0) < 0)
        {
            printf("select error\n");
            return -1;
        }
        if (FD_ISSET(s, &read_fds))
        {
            int size;
            if ((size = recv(s, message, MAXLINE, 0)) > 0)
            {
                message[size] = '\0';
                printf("%s \n", message);
            }
        }
        if (FD_ISSET(0, &read_fds))
        {
            fgets(message, MAXLINE, stdin);
            if (!strcmp(message, "q\n"))
            {
                close(s);
                return -1;
            }
            sprintf(line, "%s %s", name, message);
            send(s, line, strlen(line), 0);
        }
    }
    return 0;
}