linux 下基于socket 多客户多文件传输系统

linux 下基于socket 多客户多文件传输系统（服务端与客户端）本套系统功能简介：服务器登陆后，自动扫描指定目录中的指定文件（本文中指定为MP3文件），打印出服务器中的文件及数目，然后等待客户端的连接，一旦有客户端连接，服务器将扫描出的全部同类型文件发送给客户端，实现文件同步。

可应用于广播等应用中。

设计思路：服务器先扫描指定类型的文件，将扫描结果存于链表中。

然后建立套接字，等待客户端连接，等有客户端连接后，依次发送文件数目，文件名，文件大小及文件内容给客户端。

客户端依次接收。

设计难点在于客户端的文件内容的接收，需要文件大小控制文件内容接收循环的跳出，否则会接收下个文件的内容，造成文件接收混乱。

server 端：#include <sys/types.h>#include <sys/socket.h> // 包含套接字函数库#include <stdio.h>#include <netinet/in.h> // 包含AF_INET相关结构#include <arpa/inet.h> // 包含AF_INET相关操作的函数#include <unistd.h>#include<string.h>#include<stdlib.h>#include<fcntl.h>#include<sys/stat.h>#include<dirent.h>#define PORT 9999#define BUFFSIZE 1000#define MAXPATH 32#define LEN sizeof(struct list)int count=0; //计量歌曲数double filesize; //文件总大小struct list{char pathname[1024];char filename[512];struct list *next;};struct list *head,*p1,*p2;void scan_dir(char *dir,int depth) //定义目录扫描函数{DIR *dp;struct dirent *entry;struct stat statbuff;int l;if(!(dp=opendir(dir))){//puts("can't open");return;}chdir(dir); //切换到当前目录中去while((entry=readdir(dp))!=NULL){lstat(entry->d_name,&statbuff); //获取下一级成员属性if(S_IFDIR&statbuff.st_mode) //判断下一级成员是否是目录{if(strcmp(".",entry->d_name)==0||strcmp("..",entry->d_name)==0)continue;//printf("%*s%s/\n",depth,"",entry->d_name);scan_dir(entry->d_name,depth+4); //调用自身，扫描下一级 }else{l=strlen(entry->d_name);l-=4;if(strcmp(entry->d_name+l,".mp3")==0||strcmp(entry->d_name+l,".MP3")==0){ char path_buff[MAXPATH];getcwd(path_buff, MAXPATH);p1= malloc(LEN);strcpy(p1->pathname,path_buff);strcpy(p1->filename,entry->d_name);//printf("%s hello %s",p1->pathname,p1->filename);p1->next=0;count++;if(count==1)head=p2=p1;else{ p2->next=p1;//p2=p2->next;p2=p1;//printf("hello");}int tem;tem = statbuff.st_size;filesize+=tem;}}}chdir(".."); //回到上一级目录closedir(dp);}int print(){struct list *temp;temp=head;//printf("......here1");if(head!=NULL)do {printf("%s %s\n",temp->pathname,temp->filename);temp=temp->next;}while(temp!=NULL);return ;}int main(){puts("正在扫描全盘中...");scan_dir("/home",0);printf("列表输出如下：\n");print();puts("扫描结束\n");printf("共计%d首歌曲\n",count);printf("总大小为%3.2gMB\n",filesize/1024/1024);int server_sockfd,client_sockfd;int server_len,client_len;struct sockaddr_in server_sockaddr,client_sockaddr;server_sockfd = socket(AF_INET,SOCK_STREAM, 0); // 定义套接字类型server_sockaddr.sin_family=AF_INET;server_sockaddr.sin_port=htons(PORT);server_sockaddr.sin_addr.s_addr=INADDR_ANY;server_len=sizeof(server_sockaddr);//允许重复使用本地地址和套接字绑定int j=1;setsockopt(server_sockfd,SOL_SOCKET,SO_REUSEADDR,&j,sizeof(j));//绑定端口if(bind(server_sockfd,(struct sockaddr *)&server_sockaddr,server_len)==-1){perror("bind:");exit(1);}//监听端口if(listen(server_sockfd,5)==-1){perror("listen:");exit(1);}printf("Listening...\n");pid_t pid;client_len=sizeof(client_sockaddr);while(1){if((client_sockfd=accept(server_sockfd,(struct sockaddr*)&client_sockaddr,&client_len))==-1){perror("accept error:");exit(1);}printf("%s连接到服务器\n",inet_ntoa(client_sockaddr.sin_addr));printf("准备发送文件...\n");pid=fork(); //创建子进程if(pid==0) //子进程发送数据{//发送文件数目int countbyte;countbyte=send(client_sockfd,&count,4,0);// printf("countbyte=%d\n",countbyte);char fileinfo[100]; //定义文件信息，包括文件路径和文件名 memset(fileinfo,0,100);char filename[50];memset(filename,0,50);struct stat statbuff;struct list *temp;temp=head;if(head!=NULL)do {// printf("%s %s\n",temp->pathname,temp->filename);char c[2]={'/'};strcat(temp->pathname,c);strcat(temp->pathname,temp->filename);// printf("temp->pathname=%s\n",temp->pathname);strcpy(fileinfo,temp->pathname);strcpy(filename,temp->filename);printf("fileinfo=%s\n",fileinfo);// printf("filename=%s\n",filename);int sendbytes=0;sendbytes=send(client_sockfd,filename,50,0);printf("sendbytes=%d\n",sendbytes);//发送文件大小int filesize=0;int sendfsize;lstat(fileinfo,&statbuff);filesize=statbuff.st_size;printf("filesize =%d\n",filesize);sendfsize=send(client_sockfd,&filesize,4,0);// printf("sendfsize=%d\n",sendfsize);char buff[BUFFSIZE];memset(buff,0,BUFFSIZE);FILE * fp = fopen(fileinfo,"r");if(NULL == fp ){printf("File:Not Found\n" );}else{int file_block_length = 0;while( (file_block_length =fread(buff,sizeof(char),BUFFSIZE,fp))>0){// printf("file_block_length = %d\n",file_block_length);if(send(client_sockfd,buff,file_block_length,0)<0){printf("Send File Failed:\n");break;}memset(buff,0,BUFFSIZE);}fclose(fp);}temp=temp->next;}while(temp!=NULL);printf("文件发送完毕\n");}//end of child processif(pid>0){close(client_sockfd);}} //end of while(1)}客户端：clien.c#include <stdio.h>#include <netinet/in.h>#include <sys/types.h>#include <sys/socket.h>#include <dirent.h>#include <string.h>#include <sys/stat.h>#include <unistd.h>#include <netdb.h>#include <stdlib.h>#define IP_ADDR "192.168.182.134"int main(){unsigned char filename[50];int filesize;unsigned char databuf[1000];int sockfd;struct sockaddr_in serv_addr;// struct hostent *host;int i;int lastsize=0;// host = gethostbyname("localhost");sockfd=socket(AF_INET,SOCK_STREAM,0);serv_addr.sin_family = AF_INET;serv_addr.sin_port = htons(9999);//serv_addr.sin_addr = *((struct in_addr*)host->h_addr);serv_addr.sin_addr.s_addr = inet_addr(IP_ADDR);bzero(&(serv_addr.sin_zero),8);if(connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(struct sockaddr))==-1){perror("connect");exit(1);}//接收文件数目int count=0;int countbyte;countbyte=recv(sockfd,&count,4,0);printf("文件数目=%d\n",count);while(count--){i=recv(sockfd,filename,sizeof(filename),0); //接收文件名 // printf("recv %d bytes\n",i);printf("file name=%s\n",filename);i=recv(sockfd,&filesize,sizeof(filesize),0); //接收文件大小 // printf("recv %d bytes\n",i);printf("filesize=%d\n",filesize);lastsize=filesize; //文件大小赋给变量//接收文件内容FILE *fp = fopen(filename,"w");if(NULL == fp ){printf("File: Can Not Open To Write\n");exit(1);}i=0;while(lastsize>0){printf("lastsize=%d\n",lastsize);if(lastsize>sizeof(databuf)){i=recv(sockfd,databuf,sizeof(databuf),0);printf("接收字节i=%d\n",i);int write_length = fwrite(databuf,sizeof(char),i,fp); if (write_length<i){printf("File:Write Failed\n");break;}// if(lastsize<5000) printf("recv %d bytes\n",i);}else{printf("i'll recv %d byte only\n",lastsize);i=recv(sockfd,databuf,lastsize,0);printf("接收字节i=%d\n",i);int write_length = fwrite(databuf,sizeof(char),i,fp); if (write_length<i){printf("File:Write Failed\n");break;}// printf("*******recv %d bytes\n",i);}lastsize=lastsize-i;}fclose(fp);printf("该文件接收完毕\n");}return 0;}。