1.txt

文件管理系统：用于实现一个简单的多用户操作的文件管理系统

#include <io.h>
#include <conio.h>        //里面有clrscr()清屏函数 
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>       //内存分配函数
#include <string.h>
#include <ctype.h>


#define N  30   //用户数
#define M  20    //一个用户可保存M个文件
#define L  5     //用户只能一次打开L个文件

typedef struct MFD   //主文件目录
{
	char username[100];
    char password[100];
    FILE *fp;            //文件目录指针
}MFD;

typedef struct UFD   //用户文件目录
{
	char filename[256];
    char protect;       //保护码
    int length;         //文件长度
}UFD;

typedef struct OFD   //打开文件目录
{
	char filename[256];
    char opencode;       //打开保护码
    int *fp;              //读写指针
}OFD;

typedef struct COMM   //命令串
{
	char string[256];    //用户命令串
    struct COMM *next;   //后继指针:指向命令各参数所在的结点
}COMM;


MFD mainfd[N];        //主文件目录数组
UFD userfd[M];        //用户文件目录数组
OFD openfd[L];        //打开文件目录数组

COMM *command;        //命令串指针
char username[100];
int usernum,savenum,opennum;
int workfile;


void init();                        //初始化主文件目录数组
void init_ufd(char *username);      //初始化用户文件目录
void mesg(char *str);   //输出函数
char *getuser();        //设置用户函数声明
char *getpass();        //设置口令函数声明

COMM *readcommand();    //读命令串函数声明
void login();         //用户登录
void logout();        //用户注销
void setpass();       //设置口令
void create();         //创建用户文件
void mydelete();      //删除
void myread();        //读
void myopen();        //打开
void myclose();       //关闭
void mywrite();       //写
void help();          //帮助
void dir();           //列文件目录
void mycopy();        //复制
void myrename();      //文件改名



void main()
{ 
	init();
    while(1)
    {
		readcommand();
        if(strcmp(command->string,"create")==0)
			create();
		else if(strcmp(command->string,"delete")==0)
			mydelete();
        else if(strcmp(command->string,"open")==0)
            myopen();
        else if(strcmp(command->string,"close")==0)
            myclose();
        else if(strcmp(command->string,"read")==0)
            myread();
        else if(strcmp(command->string,"write")==0)
            mywrite();
        else if(strcmp(command->string,"copy")==0)
            mycopy();
        else if(strcmp(command->string,"rename")==0)
            myrename();
        else if(strcmp(command->string,"login")==0)
            login();
        else if(strcmp(command->string,"setpass")==0)
            setpass();
        else if(strcmp(command->string,"logout")==0)
            logout();
        else if(strcmp(command->string,"help")==0)
            help();
        else if(strcmp(command->string,"dir")==0)
            dir();
        else if(strcmp(command->string,"exit")==0)
			break;
        else 
			mesg("Bad command!");
	}
}


void mesg(char *str)
{
  printf("\n %s\n",str);
}


void init()                  //初始化主文件目录数组
{ 
	FILE *fp;       //文件指针
    char tempname[20],temppass[20];
    usernum=0;      //全局变量初始化
    savenum=0;
    opennum=0;
    strcpy(username,"");  
    //用户使用时，建立一个mainfile.txt文件，包括每个用户的用户名和口令
    //然后，才能运行此程序
    if((fp=fopen("mainfile.txt","r"))!=NULL)//以读方式打开文件mainfile.txt
    {
        while(!feof(fp))//若不是文件尾
        {
			strcpy(tempname,"");     //清空数组操作
            fgets(tempname,20,fp);   //读用户名
            if(strcmp(tempname,"")!=0)
             {
				fgets(temppass,20,fp);
                tempname[strlen(tempname)-1]='\0';      //设置串结束符
                temppass[strlen(temppass)-1]='\0';
                strcpy(mainfd[usernum].username,tempname);      //生成mainfd数组
                strcpy(mainfd[usernum].password,temppass);      //生成userfd数组
                usernum++;                                      //生成usernum的值
              }
			if(usernum>=N)
				break;
        }
       fclose(fp);
    }
}


void init_ufd(char *username)        //初始化用户文件目录
{
	FILE *fp;
    char tempfile[100],tempprot;
    int templength;
    savenum=0;
    opennum=0;
    workfile=-1;
    if((fp=fopen(username,"r+"))!=NULL)
	{
		while(!feof(fp))
        {
			strcpy(tempfile,"");
            fgets(tempfile,50,fp);
            if(strcmp(tempfile,"")!=0)
            {
				fscanf(fp,"%c",&tempprot);
                fscanf(fp,"%d",&templength);
                tempfile[strlen(tempfile)-1]='\0';
                strcpy(userfd[savenum].filename,tempfile);     //文件名
                userfd[savenum].protect=tempprot;              //保护码
                userfd[savenum].length=templength;             //文件长度
                savenum++;
                fgets(tempfile,50,fp);
			} 
		}
    }
}        


char *getuser()               //设置用户函数声明
{
	char username[20];
    char temp;
    int i;
    username[0]='\0';
    for(i=0;i<20;)
	{
		while(!kbhit());    //按用户名规则输入用户名
        temp=getch();
        if(isalnum(temp)||temp=='_'||temp==(char)13)   
		{
			username[i]=temp;
            if(username[i]==(char)13)
            {
				username[i]='\0';
                break;
			}
            putchar(temp);
            i++;
            username[i]='\0';
		}
	}
    return  username;
}



char *getpass()                //设置口令函数声明
{
	char password[20];
    char temp;
    int i;
    password[0]='\0';
    for(i=0;i<20;)
    {
		while(!kbhit());           //等待按键
        temp=getch();
        if(isalnum(temp)||temp=='_'||temp==(char)13)
        {
			password[i]=temp;
            if(password[i]==(char)13)
            {
				password[i]='\0';
                break;
			}
            putchar('*');
            i++;
            password[i]='\0';
		}
	}
  return password;
}


COMM *readcommand()               //读命令串函数声明
{
	char temp[256];
    char line[256];
    unsigned int i,end;
    COMM *newp,*p;
    command=NULL;
    strcpy(line,"");
    while(strcmp(line,"")==0)
    {
		printf("\nc:\\>");
        gets(line);           //输入一个命令串
	}
    for(i=0;i<=strlen(line);i++)
    {
		if(line[i]==' ') 
			i++;
        end=0;
        while(line[i]!='\0'&&line[i]!=' ')
        {
			temp[end]=line[i];
            end++;
            i++;
        }
        if(end>0)           //对命令行中的子串进行处理
		{
			temp[end]='\0';
            newp=(COMM*)malloc(sizeof(COMM*));
            strcpy(newp->string,temp);
            newp->next=NULL;
            if(command==NULL)  
				command=newp; //把各子串链成一个链表
            else
			{  
				p=command;
                while(p->next!=NULL)  
					p=p->next;
                p->next=newp;
			}
		}
	}
    p=command;
    return command;
}


void login()               //用户注册
{
	FILE *fp;
    int i;
    char password[20],confirm[20],tempname[20];
    if(command->next==NULL)
	{
		printf("\n User Name:");
        strcpy(tempname,getuser());             //输入用户名并且返回之
    }
    else if(command->next->next!=NULL)
	{
		mesg("Too many parameters!");
		return;
	}
    else strcpy(tempname,command->next->string);
    for(i=0;i<usernum;i++)
		if(strcmp(mainfd[i].username,tempname)==0)
			break;                              //从mainfd表中查找要注册的用户
    if(i>=usernum)                              //新用户
	{
		printf("\n new user account,enter your password twice!");
        printf("\n Password:");
        strcpy(password,getpass());             //输入口令并且返回之
		printf("\n Password:");
        strcpy(confirm,getpass());              //第二次输入口令
        if(strcmp(password,confirm)==0)         //两次输入的口令是否相同的处理情况
		{
			if(usernum>=N)                      //用户数不能超过N
				mesg("Creat new account fasle!number of user account limited.\n login false!");
            else
			{
				strcpy(mainfd[usernum].username,tempname);      //把新用户和口令填入mainfd中
                strcpy(mainfd[usernum].password,password); 
                usernum++;
                strcpy(username,tempname);
                mesg("Creat a new user!\n login success!");
                init_ufd(username);                             //初始化用户文件目录
                fp=fopen("mainfile.txt","w+");                  //把新用户填入mainfile.txt文件中
                for(i=0;i<usernum;i++)
				{
					fputs(mainfd[i].username,fp);
                    fputs("\n",fp);
                    fputs(mainfd[i].password,fp);
                    fputs("\n",fp);
				}
                fclose(fp);

			}
		}
        else                   //两次输入的口令是否相同的处理情况
		{
			mesg("Creat new account false!Error password!");
            mesg("login false!");
		}
	}
    else              //注册过的用户登陆
	{
		printf("\n Password:");
        strcpy(password,getpass());
        if(strcmp(mainfd[i].password,password)!=0)
			mesg("Login false!Error password!");
        else
		{
			mesg("Login success!");
            strcpy(username,tempname);
            init_ufd(username);
		}
	}
}


void setpass()              //重新设置口令
{
	int i;
    FILE *fp;
    char oldpass[20],newpass[20],confirm[20];
    if(strcmp(username,"")==0)  
		mesg("No user login!");
    else
	{
		printf("\n Old password:");
        strcpy(oldpass,getpass());
        for(i=0;i<usernum;i++)
			if(strcmp(mainfd[i].username,username)==0) 
				break;
        if(strcmp(mainfd[i].password,oldpass)!=0)
			mesg("Old password error!");
        else
		{
			printf("\n New password:");
            strcpy(newpass,getpass());
            printf("\n Confirm password:");
            strcpy(confirm,getpass());
            if(strcmp(newpass,confirm)!=0)
				mesg("Password not changed! cinfirm different.");
			else
			{
				strcpy(mainfd[i].password,newpass);
                mesg("Password changed!");
                fp=fopen("mainfile.txt","w+");
                for(i=0;i<usernum;i++)             //写回到mainfile.txt
                {
					fputs(mainfd[i].username,fp);
                    fputs("\n",fp);
                    fputs(mainfd[i].password,fp);
                    fputs("\n",fp);
                }
				fclose(fp);
			}
		}
	}
}


void logout()            //用户注销
{
	if(command->next!=NULL)
		mesg("Too many parameters!");
	else
	{
		if(strcmp(username,"")==0) 
			mesg("No user login!");
	    else
		{
			strcpy(username,"");
            opennum=0;
            savenum=0;
            workfile=-1;
            mesg("User logout!");
		}
	}
}


void create()                //创建用户文件
{
	int i;
    FILE *fp;
    if(strcmp(username,"")==0) 
		mesg("No user login!");
    else
	{
		if(command->next==NULL) 
			mesg("Too few parameters!");
        else if(command->next->next!=NULL) 
			mesg("Too many parameters!");
        else
		{
			for(i=0;i<savenum;i++)
		    if(strcmp(userfd[i].filename,command->next->string)==0) 
				break;
	        if(i<savenum)                 //文件已经存在的情况 
				mesg("Error! the file already existed!");
            else if(savenum>=M)           //保存的文件数目超过M的处理情况
				mesg("Error! cannot create file! nimber of files limited!");
	        else
			{
				strcpy(userfd[savenum].filename,command->next->string);
                userfd[savenum].protect='r';
                userfd[savenum].length=rand();
                savenum++;
                mesg("Create file success!");
                fp=fopen(username,"w+");              //写回到文件username
                for(i=0;i<savenum;i++)         
				{
					fputs(userfd[i].filename,fp);
                    fputs("\n",fp);
                    fprintf(fp,"%c\n%d\n",userfd[i].protect,userfd[i].length);
				}
		        fclose(fp);
			}
		}
	}
}


void myopen()           //打开文件
{
	int i;
    int type=0;
    char tempcode;
    char tempfile[100];
    if(strcmp(username,"")==0) 
		mesg("No user login!");
	else
		if(command->next==NULL) 
			mesg("Too few parameters!");
		else                              //存在2个或3个参数的处理
		{
			strcpy(tempfile,"");
			tempcode='r';
	        if(strcmp(command->next->string,"/r")==0)
			{
				tempcode='r';
				type=1;
			}
			else if(strcmp(command->next->string,"/w")==0)
			{
				tempcode='w';
				type=1;
			}
		  	else if(strcmp(command->next->string,"/d")==0)
			{
				tempcode='d';
			    type=1;
			}
            else if(command->next->string[0]=='/') 
				mesg("Error! /r /w /d request!");
            else if(command->next->next!=NULL) 
				mesg("Too many parameters!");
			else 
				strcpy(tempfile,command->next->string);
			if(type==1)                  //三个参数的情况补充
				if(command->next->next!=NULL)
					if(command->next->next->next!=NULL)
						mesg("Too many parameters!");
					else strcpy(tempfile,command->next->next->string);
				else mesg("Too few parameters!");
			if(strcmp(tempfile,"")!=0)
			{