server_socket.c

/*
I Used minGw to Compile.
Compile succeeded but execution was Failed!
I think that's because of header file or window socket system.
*/

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<winsock2.h>
//#include<arpa/inet.h>
#include<sys/types.h>
// #include<sys/socket.h>

void error_handling(char *message);


int main(int argc, char **argv)
{
	int serv_sock;
	int clnt_sock;
	struct sockaddr_in serv_addr;
	struct sockaddr_in clnt_addr;
	int clnt_addr_size;
	char message[]= "Hello World!\n";

	if(argc!=2)
	{
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}

	serv_sock = socket(PF_INET, SOCK_STREAM, 0); //서버 소켓 생성
	if(serv_sock == -1)
	{
		printf("%d\n", serv_sock);
		error_handling("socket() error");
	}

	memset(&serv_addr, 0, sizeof(serv_addr));
	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) //소켓에 주소 할당
		error_handling("bind() error");

	if(listen(serv_sock, 5)==-1) //연결 요청 대기
		error_handling("listen() error");

	clnt_addr_size=sizeof(clnt_addr);
	clnt_sock=accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size); //연결 요청 수락

	if(clnt_sock==-1)
		error_handling("accept() error");
	write(clnt_sock, message, sizeof(message)); //데이터 전송
	close(clnt_sock);
	return 0;
}

void error_handling(char *message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}