리눅스 소켓 예제소스

Server.c
#include <stdio.h> 
#include <sys/types.h> 
#include <sys/socket.h> 
#include <netinet/in.h> 
#include <arpa/inet.h> 
#define SERV_TCP_PORT 1111                 // 개방할 포트
#define SERV_ADDR "111.111.111.111"        // 서버 IP
main()
{ 
        int s1,s2,x; 
        struct sockaddr_in serv_addr, cli_addr; 
        char buf[20]; 
        size_t xx; 
        printf("Hi, I am the server\n"); 
        bzero((char *)&serv_addr, sizeof(serv_addr)); 
        serv_addr.sin_family=AF_INET; 
        serv_addr.sin_addr.s_addr=inet_addr(SERV_ADDR); 
        serv_addr.sin_port=htons(SERV_TCP_PORT); 
        if((s1=socket(PF_INET, SOCK_STREAM, 0))<0)
        { 
                printf("socket creation error\n"); 
                exit(1); 
        } 
        printf("socket created successfully. socket num is %d\n", s1); 
        x=bind(s1, (struct sockaddr *)&serv_addr, sizeof(serv_addr)); 
        if (x < 0)
        { 
                printf("binding failed\n"); 
                exit(1); 
        } 
        printf("binding passed\n"); 
        listen(s1, 5); 
        xx = sizeof(cli_addr); 
        s2 = accept(s1,(struct sockaddr *)&cli_addr,&xx); 
        printf("we passed accept. new socket num is %d\n", s2); 
        read(s2,buf,10); 
        buf[10]=0; 
        printf("we got %s from cli\n",buf); 
        printf("what do you want to send to cli? enter your string\n"); 
        scanf("%s", buf); 
        write(s2,buf,strlen(buf)); 
        exit(0); 
} 

Client.c
#include <stdio.h> 
#include <sys/types.h> 
#include <sys/socket.h> 
#include <netinet/in.h> 
#include <arpa/inet.h> 
#define SERV_TCP_PORT 1111                      // 연결할 포트
#define SERV_ADDR "111.111.111.111"              // 접속할 서버의 IP
main()
{ 
        int x; 
        struct sockaddr_in  serv_addr; 
        char buf[50]; 
        printf("Hi, I am the client\n"); 
        bzero((char *) &serv_addr, sizeof(serv_addr)); 
        serv_addr.sin_family = PF_INET; 
        serv_addr.sin_addr.s_addr = inet_addr(SERV_ADDR); 
        serv_addr.sin_port = htons(SERV_TCP_PORT); 
        /* open a tcp socket*/ 
        if ( (x =socket(PF_INET, SOCK_STREAM,0)) < 0)
        { 
               printf("socket creation error\n"); 
               exit(1); 
         } 
         printf(" socket opened successfully. socket num is %d\n", x); 
         /* connect to  the server */ 
         if (connect(x, (struct sockaddr *) &serv_addr, sizeof(serv_addr))<0)
         { 
               printf("can't connect to the server\n"); 
               exit(1); 
         } 
         /* send input str to the server */ 
         printf("now i am connected to the erver. enter a string to send\n"); 
         scanf("%s", buf); 
         write(x,buf,strlen(buf)); 
         printf("now let's read from the server\n"); 
         read(x,buf,10); 
         buf[10]=0; 
         printf("what echoed from the server is %s\n",buf); 
}