소켓통신 서버소스

/*
 ============================================================================
 Name        : SoketServer.c
 Author      : SeYUN
 Version     :
 Copyright   : Your copyright notice
 Description : Hello World in C, Ansi-style
 ============================================================================
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#define  BUFF_SIZE   1024
int   main( void)
{
   int   server_socket;
   int   client_socket;
   int   client_addr_size;
   struct sockaddr_in   server_addr;
   struct sockaddr_in   client_addr;
   char   buff_rcv[BUFF_SIZE+5];
   char   buff_snd[BUFF_SIZE+5];
   printf("socket 생성 전:\n");
   /* return 값은 소켓 식별자 이나 -1은 오류 리턴임 */
   server_socket  = socket( PF_INET, SOCK_STREAM, 0);
   if( -1 == server_socket)
   {
      printf( "server socket 생성 실패\n");
      exit( 1);
   }
   printf("socket 생성 완료\n");
   memset( &server_addr, 0, sizeof( server_addr));
   server_addr.sin_family     = AF_INET;
   server_addr.sin_port       = htons( 4000);
   server_addr.sin_addr.s_addr= htonl( INADDR_ANY);
   if( -1 == bind( server_socket, (struct sockaddr*)&server_addr, sizeof( server_addr) ) )
   {
      printf( "bind() 실행 에러\n");
      exit( 1);
   }
   printf("listen 시작\n");
   if( -1 == listen(server_socket, 5))
   {
      printf( "listen() 실행 실패\n");
      exit( 1);
   }
   while( 1)
   {
      client_addr_size  = sizeof( client_addr);
      client_socket     = accept( server_socket, (struct sockaddr*)&client_addr, &client_addr_size);
      if ( -1 == client_socket)
      {
         printf( "클라이언트 연결 수락 실패\n");
         exit( 1);
      }
      read ( client_socket, buff_rcv, BUFF_SIZE);
      printf( "receive: %s\n", buff_rcv);
      sprintf( buff_snd, "%d : %s", strlen( buff_rcv), buff_rcv);
      write( client_socket, buff_snd, strlen( buff_snd)+1);          // +1: NULL까지 포함해서 전송
      close( client_socket);
   }
   printf("프로그램 종료\n");
}