题目要求：

 

编一个通过屏幕选择命令的文件管理系统，每屏要为用户提供足够的选择信息，不需要打入冗长的命令。

代码：

#include 
     
      #include 
      
       #include 
       
        using namespace std;struct UFD //用户目录文件{    string File_Name; //文件名    bool R,W,X; // 读写执行    int Len_File; //文件大小};struct MFD //主文件夹目录{    string User_Name; //用户名    UFD * Pointer; //用户文件目录指针};struct AFD //运行文件目录{    int File_ID;// 文件号    bool R, W, X;    int Pointer;//读写指针};class FILE_SYSTEM{public:    void Inital();    void Start();private:    int Num_User; //用户数量    int Num_File; //每个用户可保存的文件数    int MAX_Open_File; //打开的最大文件数    MFD * Mfd; // 主文件目录    UFD * Ufd; // 用户文件目录    AFD * Afd; //运行文件目录};int main(){    FILE_SYSTEM FS;    FS.Inital();    FS.Start();    return 0;}void FILE_SYSTEM::Inital(){    Num_File = 10;    Num_User = 10;    MAX_Open_File = 5;    //UFD    Ufd = new UFD[Num_User*Num_File];    //MFD    Mfd = new MFD[Num_User];    for(int i = 0 ; i < Num_User; i++)    {        Mfd[i].Pointer = &(Ufd[i*Num_File]);    }    //AFD    Afd = new AFD[MAX_Open_File];    Mfd[0].User_Name="wzn";    Ufd[0].File_Name="1.txt";    Ufd[0].Len_File=10;    Ufd[0].R=true;    Ufd[0].W=false;    Ufd[0].X =false;    Ufd[1].File_Name="2.txt";    Ufd[1].Len_File=15;    Ufd[1].R=false;    Ufd[1].W=false;    Ufd[1].X =true;    for(int i = 2; i < Num_File; i++) //其他人没有文件存在    {        Ufd[i].File_Name="";        Ufd[i].Len_File=-1;        Ufd[i].R=false;        Ufd[i].W=false;        Ufd[i].X =false;    }}void showOrder(){    cout << "Order list" << endl;    cout << "\t1. dir\t";    cout << "\t2. diropen" << endl;    cout << "\t3. create";    cout << "\t4. delete" << endl;    cout << "\t5. open\t";    cout << "\t6. logout" << endl;    cout << "\t7. close";    cout << "\t8. read" << endl;    cout << "\t9. write\t";    cout << "\t10. shutdown" << endl;}void FILE_SYSTEM::Start(){    showOrder();    int User_ID,i;    int Num_Open_File,tmp_len; //当前用户打开文件数    string User_Name,tmp;//当前登录的用户名    int cmd; //用户输入命令    UFD * ufd;    char choice;    do  //打开计算机    {        do        {            cout << "User Name:";            cin >> User_Name;            for(User_ID = 0; User_ID < Num_User; User_ID++)            {                if(Mfd[User_ID].User_Name == User_Name)                    break;            }            if(User_ID == Num_User)                cout << "No such User name,please try again!" << endl;        }        while(User_ID == Num_User);        cout << "Welcome to login, " << User_Name << "!" << endl;        ufd = Mfd[User_ID].Pointer;        //初始化文件列表        for(i = 0 ; i < MAX_Open_File; i++)        {            Afd[i].File_ID = -1;        }        Num_Open_File = 0;        do //命令处理        {            //模拟命令行：            cout << "["<
        
         <<"]~";            cin >> cmd;            if(cmd == 1)            {                cout << endl;                cout << "Owner of Files:" << User_Name << endl;                cout << "\tState\tLength\tFileName" << endl;                for(i = 0 ; i < Num_File; i++)                {                    if(ufd[i].Len_File != -1)                    {                        cout << "\t";                        if(ufd[i].R == true)cout << "R";                        else cout << "-";                        if(ufd[i].W == true)cout << "W";                        else cout << "-";                        if(ufd[i].X == true)cout << "X";                        else cout << "-";                        cout << "\t";                        cout << ufd[i].Len_File << "\t";                        cout << ufd[i].File_Name << endl;                    }                }                cout << endl;            }            else if(cmd == 2)            {                cout << endl;                cout << "Opened Files of " << User_Name << endl;                cout << "\t" << "State\t" << "Open File name" << endl;                for(i = 0 ; i < MAX_Open_File; i++)                {                    if(Afd[i].File_ID != -1)                    {                        cout << "\t";                        if(Afd[i].R == true)cout << "R";                        else cout << "-";                        if(Afd[i].W == true)cout << "W";                        else cout << "-";                        if(Afd[i].X == true)cout << "X";                        else cout << "-";                        cout << "\t";                        cout << ufd[Afd[i].File_ID].File_Name << endl;                    }                }                cout << endl;            }            else if(cmd == 3)            {                for(i=0; i
         
          > tmp;                    ufd[i].File_Name = tmp;                    cout << "Read(y/n):";                    choice = getch();                    if(choice == 'y')ufd[i].R = true;                    else ufd[i].R = false;                    cout << endl;                    cout << "Write(y/n):";                    choice = getch();                    if(choice == 'y')ufd[i].W = true;                    else ufd[i].W = false;                    cout << endl;                    cout << "Execute(y/n):";                    choice = getch();                    if(choice == 'y')ufd[i].X = true;                    else ufd[i].X = false;                    cout << endl;                    cout << "Length:";                    cin >> tmp_len;                    if(tmp_len > 0)                        ufd[i].Len_File = tmp_len;                    cout << "New File: " << ufd[i].File_Name << " is Created" << endl;                }            }            else if(cmd == 4)            {                cout << "Enter Delete file name:";                cin >> tmp;                for(i = 0 ; i < Num_File; i++)                {                    if((ufd[i].Len_File != -1) && (ufd[i].File_Name == tmp))                        break;                }                if(i == Num_File)                {                    cout << "NOT FOUND!" << endl;                }                else                {                    ufd[i].Len_File = -1; //delete the file                    cout << "The File:" << ufd[i].File_Name << " is deleted!" << endl;                }            }            else if(cmd == 5)            {                if(Num_Open_File == MAX_Open_File)                    cout << "Can't Open anymore!" << endl;                else                {                    cout << "Open file 's name:";                    cin >> tmp;                    for(i=0; i 
          
           > tmp; for(i = 0 ; i < Num_File ; i++) { if((ufd[i].Len_File != -1) && (ufd[i].File_Name == tmp)) break; } if(i == Num_File) { cout << "Not found！" << endl; } else { int t; for(t = 0 ; t < MAX_Open_File ; t++) { if(Afd[t].File_ID == i) break; } if(t == MAX_Open_File) cout << "Not found" << endl; else { Afd[t].File_ID = -1; Num_Open_File--; cout << tmp << " is closed" << endl; } } } else if(cmd == 8) { cout << "Read file Name:"; cin >> tmp; for(i = 0 ; i < Num_File; i++) { if(ufd[i].File_Name == tmp && ufd[i].Len_File != -1) break; } if(i == Num_File) { cout << "Not Found" << endl; } else { int t; for(t = 0 ; t < MAX_Open_File; t++) { if(Afd[t].File_ID == i) break; } if(t == MAX_Open_File) cout << "No Enough Space" << endl; else { if(Afd[t].R == true) { cout << "You can read this file" << endl; } else { cout << "Error:Not have Power of Open" << endl; } } } } else if(cmd == 9) { cout << "enter write file name:"; cin >> tmp; for(i = 0 ; i < Num_File ; i++) if(ufd[i].Len_File!=-1&&ufd[i].File_Name==tmp) break; if(i == Num_File) { cout << "No such file" << endl; } else { int t; for(t = 0 ; t < MAX_Open_File; t++) { if(Afd[t].File_ID == i) break; } if(t == MAX_Open_File) { cout << "The file:" << tmp << "is not open" <