file_client.c

/*
pineoc, 2015-03-23
week 4 network programming
file server & client
client code
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char* msg);

int main(int argc,char* argv[])
{
	int sd;//socket id
	FILE* fp;//file pointer

	char buf[BUF_SIZE];
	int read_cnt;
	struct sockaddr_in serv_addr;

	if(argc!=3)
	{
		printf("Usage : %s <IP> <port> \n",argv[0]);
        exit(1);
	}

	fp=fopen("receive.dat","wb");

	sd = socket(PF_INET,SOCK_STREAM,0);
	if(sd==-1)
        error_handling("socket() err");

    memset(&serv_addr,0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_addr.sin_port = htons(atoi(argv[2]));

    connect(sd,(struct sockaddr*)&serv_addr,sizeof(serv_addr));

    while((read_cnt=read(sd,buf,BUF_SIZE))!=0)
    	fwrite((void*)buf,1,read_cnt,fp);

    puts("receive file data");
    write(sd,"T u",4);
    fclose(fp);
    close(sd);

	return 0;
}

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

file_server.c

/*
pineoc, 2015-03-23
week 4 network programming
file server & client
server code
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char* msg);

int main(int argc,char* argv[])
{
	int serv_sd,clnt_sd;
	FILE* fp;
	char buf[BUF_SIZE];
	int read_cnt;

	struct sockaddr_in serv_addr,clnt_addr;
	socklen_t clnt_addr_size;

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

	fp=fopen("file_server.c","rb");
	serv_sd = socket(PF_INET,SOCK_STREAM,0);

	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]));

	bind(serv_sd,(struct sockaddr*)&serv_addr,sizeof(serv_addr));
	listen(serv_sd,5);

	clnt_addr_size=sizeof(clnt_addr);
	clnt_sd=accept(serv_sd,(struct sockaddr*)&clnt_addr,&-clnt_addr_size);

	while(1)
	{
		read_cnt=fread((void*)buf,1,BUF_SIZE,fp);
		if(read_cnt<BUF_SIZE)
		{
			write(clnt_sd,buf,read_cnt);
			break;
		}
		write(clnt_sd,buf,BUF_SIZE);
	}
	shutdown(clnt_sd,SHUT_WR);
	read(clnt_sd,buf,BUF_SIZE);
	printf("Message from client : %s \n",buf);

	fclose(fp);
	close(clnt_sd);
	close(serv_sd);

	return 0;
}

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