4장 echo_server.c 예외 처리

int main(int argc, char **argv)
{
    int server_sockfd, client_sockfd;
    int client_len, n;
    char buf[MAXBUF];
    struct sockaddr_in clientaddr, serveraddr;

    client_len = sizeof(clientaddr);
    if ((server_sockfd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP )) == -1)
    {
        perror("socket error : ");
        exit(0);
    }
    bzero(&serveraddr, sizeof(serveraddr));
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
    serveraddr.sin_port = htons(atoi(argv[1]));

int main(int argc, char **argv)
{
    int server_sockfd, client_sockfd;
    int client_len, n;
    char buf[MAXBUF];
    struct sockaddr_in clientaddr, serveraddr;

    // 프로그램 실행 인자를 검사한다.
    // 만약 실행인자가 없으면 사용법을 출력하고 프로세스를 종료한다.
    if(argc !=2 )
    {
        fprintf(stderr,"Usage : %s [port]\n", argv[0]);
        return 1;
    }
    client_len = sizeof(clientaddr);
    if ((server_sockfd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP )) == -1)
    {
        perror("socket error : ");
        exit(0);
    }

#include <sys/socket.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>

#define MAXBUF 1024
int main(int argc, char **argv)
{
    int server_sockfd, client_sockfd;
    int client_len, n;
    char buf[MAXBUF];
    struct sockaddr_in clientaddr, serveraddr;

    if(argc !=2 )
    {
        fprintf(stderr,"Usage : %s [port]\n", argv[0]);
        return 1;
    }
    client_len = sizeof(clientaddr);
    if ((server_sockfd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP )) == -1)
    {
        perror("socket error : ");
        exit(0);
    }
    bzero(&serveraddr, sizeof(serveraddr));
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
    serveraddr.sin_port = htons(atoi(argv[1]));

    bind (server_sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));
    listen(server_sockfd, 5);

    while(1)
    {
        memset(buf, 0x00, MAXBUF);
        client_sockfd = accept(server_sockfd, (struct sockaddr *)&clientaddr,
            &client_len);
        printf("New Client Connect: %s\n", inet_ntoa(clientaddr.sin_addr));
        if ((n = read(client_sockfd, buf, MAXBUF)) <= 0)
        {
            close(client_sockfd);
            continue;
        }
        if (write(client_sockfd, buf, MAXBUF) <=0)
        {
            perror("write error : ");
            close(client_sockfd);
        }
        close(client_sockfd);
    }
    close(server_sockfd);
    return 0;
}