網路程式設計——3.TCP/UDP實現跨平臺檔案傳輸
阿新 • • 發佈：2019-01-07
一、實驗目的
在上次檔案傳輸的程式基礎上，利用循環面向連線、迴圈無連線方式完成linux和windows平臺的檔案傳輸,並完成客戶端、伺服器端程式碼的封裝。
二、實驗分析
1.使用TCP實現
- 在上次實驗基礎上，使用tcp_server.c的程式碼，只需修改為迴圈方式即可，然後作為Linux伺服器使用
- 編寫Windows下的客戶端程式，進行檔案傳送
2.使用UDP實現
- 在上次實驗的基礎上，使用udp_client.c的程式碼，只需更改IP和埠號即可
- 編寫Windows下伺服器端程式，進行檔案接收
三、實驗內容
1.循環面向連線方式（TCP）
1.tcp_server.c
//Run in Linux #include <sys/types.h> #include <string.h> #include <stdio.h> #include <stdlib.h> #include <sys/socket.h> #include <arpa/inet.h> #include <signal.h> #define PORT 8888 #define BUFFER_SIZE 1024 void get_filename(char *filepath,char *filename) { /*解析檔名*/ int i=0,k=0; for(i=strlen(filepath);i>=0;i--) { if(filepath[i]!='/') { k++; } else break; } strcpy(filename,filepath+(strlen(filepath)-k)+1); } void process_conn_server(int sd) { ssize_t size = 0; char buffer[BUFFER_SIZE]; FILE *stream; char filepath[100]; strcpy(buffer,"please enter a path!\n"); send(sd,buffer,BUFFER_SIZE,0); int length = 0; memset(filepath,'\0',sizeof(filepath)); length = recv(sd,filepath,100,0); if(length < 0){ printf("recv error!\n"); } else { char filename[100] = {'\0'}; get_filename(filepath,filename); printf("server: filename:%s\n",filename); if( (stream=fopen(filename, "w")) == NULL){ printf("server:open file error!\n"); return; } while(1){/*讀取檔案並寫入檔案流*/ size = recv(sd, buffer, BUFFER_SIZE,0); printf("server:size:%d\n",size); if(size <= 0){ break; } int write_len=fwrite(buffer, sizeof(char), size, stream); } printf("recv finished!\n"); fclose(stream); } } int main(int argc, char *argv[]){ int socksd,sockcd; struct sockaddr_in server,client; pid_t pid; if( (socksd = socket(AF_INET,SOCK_STREAM,0)) < 0) { printf("socket create error!\n"); return -1; } printf("socket create success!\n"); /*加入此程式碼是為了避免再次開啟伺服器程式出現bind error的錯誤*/ int on = 1; int ret = setsockopt(socksd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); memset(&server,0,sizeof(server)); server.sin_family = AF_INET; server.sin_addr.s_addr = htonl(INADDR_ANY); server.sin_port = htons(PORT); if( (bind(socksd,(struct sockaddr*)&server,sizeof(server)) < 0)) { printf("socket bind error!\n"); return -1; } printf("socket bind success!\n"); if( (listen(socksd,10)) < 0) { printf("socket listen error!\n"); return -1; } printf("socket listen success!\n"); printf("waiting...\n"); /*顯示核是sigchld訊號*/ if(signal(SIGCHLD, SIG_IGN) == SIG_ERR){ perror("signal error"); return EXIT_SUCCESS; } while(1){ socklen_t addr_len = sizeof(struct sockaddr); if( (sockcd = accept(socksd, (struct sockaddr*)&client, &addr_len)) < 0) { //出錯 continue; } printf("server:accept\n"); //different from exp2 process_conn_server(sockcd); close(sockcd);/*在子程序中關閉伺服器的監聽*/ } return 0; }
2.tcp_client.c
//Run in Windows #pragma comment(lib,"ws2_32") #include <stdio.h> #include <winsock.h> #include <fcntl.h> #define PORT 8888 #define BUFFER_SIZE 1024 typedef struct sockaddr_in addr; int Initsocket(void); void process_conn_client(SOCKET s); int Initsocket(void) { WSADATA wsadata; WORD version; int err; version = MAKEWORD(2, 2); err = WSAStartup(version, &wsadata); if(err) { printf("Error %d:winsock not available\n",err); return 1; } return 0; } void process_conn_client(SOCKET s) { ssize_t size = 0; char buffer[BUFFER_SIZE]; FILE *stream; char filepath[100] = {'\0'}; size = recv(s, buffer, BUFFER_SIZE,0); if(size < 0) printf("read error!\n"); printf("%s",buffer); scanf("%s",filepath); send(s,filepath,100,0); if( (stream = fopen(filepath,"r")) == NULL) { printf("client:open file error!\n"); return; } printf("sending!\n"); while(1){ size = fread(buffer,sizeof(char),BUFFER_SIZE,stream); if(size <= 0){ break; } send(s,buffer,size,0); } printf("send finished!\n"); fclose(stream); } int main() { SOCKET client; int err; addr server_addr; Initsocket(); if( (client = socket(PF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET ) { printf("no more socket resource\n"); return 1; } //伺服器地址初始化 server_addr.sin_family = PF_INET; server_addr.sin_port = htons(PORT); server_addr.sin_addr.S_un.S_addr = inet_addr("192.168.195.137");//使用自己伺服器端的IP if( (err = connect(client, (struct sockaddr*) &server_addr, sizeof(addr))) == INVALID_SOCKET) { printf("error %d:cannot connect to server\n",err); return 1; } else printf("link server is successful\n"); process_conn_client(client); closesocket(client); WSACleanup(); return 0; }
3.執行結果
- Linux作為伺服器端
- Windows作為客戶端
2.迴圈非連線方式（UDP）
1.udp_server.c
//Run in Windows
#pragma comment(lib,"ws2_32")
#include <stdio.h>
#include <winsock.h>
#include <fcntl.h>
#define PORT 8888
#define BUFFER_SIZE 1024
typedef struct sockaddr_in addr;
int Initsocket(void);
int Initsocket(void)
{
WSADATA wsadata;
WORD version;
int err;
version = MAKEWORD(2, 2);
err = WSAStartup(version, &wsadata);
if(err)
{
printf("Error %d:winsock not available\n",err);
return 1;
}
return 0;
}
void get_filename(char *filepath,char *filename)
{
/*解析檔名*/
int i=0,k=0;
for(i=strlen(filepath);i>=0;i--)
{
if(filepath[i]!='/')
{
k++;
}
else
break;
}
strcpy(filename,filepath+(strlen(filepath)-k)+1);
}
void process_conn_server(SOCKET s)
{
addr client;
int addrlen;
char filename[100];
char filepath[100];
char *buffer;//file buffer
int fileTrans;
buffer = (char *)malloc(sizeof(char)*BUFFER_SIZE);
memset(buffer,0,BUFFER_SIZE);
int lenfilepath;
FILE *fp;
int writelength;
addrlen = sizeof(client);
while(1)
{
memset(filename,'\0',sizeof(filename));
memset(filepath,'\0',sizeof(filepath));
//接受檔案路徑，返回檔案路徑的長度
lenfilepath = recvfrom(s,filepath,100,0,(struct sockaddr*)&client,&addrlen);
ntohl(client.sin_addr.s_addr);
printf("%s",inet_ntoa(client.sin_addr));
printf("filepath :%s\n",filepath);
if(lenfilepath<0)
{
printf("recv error!\n");
exit(1);
}
//從路徑中提取出檔名
else
{
get_filename(filepath,filename);
}
printf("filename :%s\n",filename);
//以寫的方式開啟檔案
fp = fopen(filename,"w");
if(fp!=NULL)
{
//接受檔案內容buffer，存在buffer中
while((fileTrans =recvfrom(s,buffer,BUFFER_SIZE,0,(struct sockaddr*)&client,&addrlen)))
{
printf("fileTrans: %d\n",fileTrans);
if(fileTrans<0)
{
printf("recv error!\n");
break;
}
//把buffter中的檔案內容寫到fp指標指的檔案中
writelength = fwrite(buffer,sizeof(char),fileTrans,fp);
if(writelength <fileTrans)
{
printf("write error!\n");
break;
}
memset(buffer,0,BUFFER_SIZE);
}
printf("recv finished!\n");
fclose(fp);
}
//客戶端如果檔名不存在直接終止程式導致filename是null
else
{
printf("filename is null!\n");
}
}
}
int main()
{
SOCKET sockfd;
int err;
addr server_addr;
Initsocket();
if( (sockfd = socket(PF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET )
{
printf("no more socket resource\n");
return 1;
}
//伺服器地址初始化
memset(&server_addr,0,sizeof(server_addr));
server_addr.sin_family = PF_INET;
server_addr.sin_port = htons(PORT);
server_addr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
if( (err = bind(sockfd,(struct sockaddr*)&server_addr,sizeof(server_addr))) == -1)
{
printf("bind error!\n");
}
else
{
printf("bind success!\n");
}
process_conn_server(sockfd);
closesocket(sockfd);
WSACleanup();
return 0;
}2.udp_client.c
//Run in Linux
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <string.h>
#include <netinet/in.h>
#include <errno.h>
#include <memory.h>
#include <stdlib.h> //for malloc
#include <arpa/inet.h>
#define BUFFER_SIZE 1024
int main()
{
int sockcd;
struct sockaddr_in server;
char filepath[100];//file to translate
FILE *fp;
int lenpath; //filepath length
char *buffer;//file buffer
int fileTrans;
buffer = (char *)malloc(sizeof(char)*BUFFER_SIZE);
bzero(buffer,BUFFER_SIZE);
//memset(buffer,0,sizeof(buffer));
//建立套接字
if((sockcd = socket(AF_INET,SOCK_DGRAM,0))<0)
{
printf("socket build error!\n");
}
memset(&server,0,sizeof(server));
server.sin_family= AF_INET;
server.sin_port = htons(8888);
if(inet_pton(AF_INET,"192.168.195.1",&server.sin_addr)<0)
{
printf("inet_pton error!\n");
}
printf("file path:\n");
scanf("%s",filepath);//get filepath
//以讀的方式開啟檔案
fp = fopen(filepath,"r");//opne file
//檔案找不到直接退出程式
if(fp==NULL)
{
printf("filepath not found!\n");
return 0;
}
printf("filepath : %s\n",filepath);
lenpath = sendto(sockcd,filepath,strlen(filepath),0,(struct sockaddr *)&server,sizeof(server));// put file path to sever
if(lenpath<0)
{
printf("filepath send error!\n");
}
else
{
printf("filepath send success!\n");
}
sleep(3);
while((fileTrans = fread(buffer,sizeof(char),BUFFER_SIZE,fp)) >= 0)
{
printf("fileTrans =%d\n",fileTrans);
//傳送檔案的內容
int flag;
if( (flag = sendto(sockcd,buffer,fileTrans,0,(struct sockaddr *)&server,sizeof(server))) < 0)
{
printf("send failed!\n");
break;
}
else if(flag == 0){
printf("send finished!\n");
break;
}
bzero(buffer,BUFFER_SIZE);
//memset(buffer,0,sizeof(buffer));
}
fclose(fp);
close(sockcd);
return 0;
}3.執行結果
-
LINUX作為客戶端
-
WINDOWS作為伺服器端
-
傳輸成功
