[C]소켓프로그래밍

server.c

#include<stdio.h>
#include<string.h>
#include<unistd.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<arpa/inet.h>
int main(){
    printf("create server socket discripter \n");
    
    int serv_socket = socket(AF_INET,SOCK_STREAM,0);
 
    if(serv_socket == -1){
        printf("fail creating socker\n");
        exit(1);
    }
 
    printf("create server structure\n");
    struct sockaddr_in serv_addr;
    memset(&serv_addr,0,sizeof(serv_addr));
 
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(4321);
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    
    if(bind(serv_socket,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) == -1){
        printf("bind error\n");
        exit(1);
    }
    printf("binding succes\n");
 
    if(listen(serv_socket,10) == -1){
        printf("listen errorn");
        exit(1);
    }
    printf("listen succes\n");
 
    int clnt_socket;
    struct sockaddr_in clnt_addr;
    int clnt_addr_size = sizeof(clnt_addr);
 
    char message[100];
 
    memset(&clnt_addr,0,sizeof(clnt_addr)); 
 
    clnt_socket = accept(serv_socket,(struct sockaddr *)&clnt_addr,&clnt_addr_size);
    if(clnt_socket == -1){
        printf("accept error\n");
        exit(1);
    }
 
    recv(clnt_socket,message,100,MSG_OOB);
    printf("recv:%s\n",message);
    send(clnt_socket,message,sizeof(message),0);
    close(clnt_socket);        
    
    
    return 0;
}