Two Level Directory Program in C

There are many types of structures of directory in the Operating System. The simplest one of them is Two Level Directory structure. In this type of structure, there are many users and there are multiple main directories. Inside a main directory, there are many sub-directories responsible for storing multiple files. There are many different files stored inside these sub-directories. These sub-directories house all the files in the system. Although implementation of such a structure is not very simple, it is an effective structure. Here, two files can have the same name as long as they are not contained inside the same sub-directories. Similarly, two sub-directories can have the same as long as they are not contained in the same main directory. This system is very complex and very large.  Searching for files becomes easier due to path name and user-grouping.

Two Level Directory Program in OS

Two level directory Program in C++


#include <iostream>
#include <string>

using namespace std;

string root, dirNames[10], sdirNames[100], fNames[1000];
int flag = 0, sdCount[10] = {0}, fCount[100] = {0};

int searchDir(string tempDir){
    for (int i = 0; i < flag; i++){
        if (dirNames[i] == tempDir)
            return i;
    }
    return -1;
}

int searchSDir(string tempSDir, int x, int i){
    for (int j = x; j < i; j++){
        if (sdirNames[j] == tempSDir)
            return j;
    }
    return -1;
}

int searchFile(string tempFile, int s, int f){
    for (int i = s; i < f; i++){
        if (fNames[i] == tempFile)
            return i;
    }
    return -1;
}

void addDir(){
    string tempDir;
    cout << "Enter the name of the directory to be created: ";
    cin >> tempDir;
    int x = searchDir(tempDir);
    if (x != -1)
        cout << "\nDirectory already exists!\n";
    else
        dirNames[flag++] = tempDir;
}

void addSDir(){
    int cv = 1;
    string temp;
    if (flag == 0){
        cout << "\nPlease create a directory first!\n";
        return;
    }
    cout << "Enter the name of the directory inside which the sub-directory is to be created: ";
    cin >> temp;
    int x = searchDir(temp);
    int i = x;
    if (x == -1){
        cout << "\nDirectory does not exist!" << endl;
        return;
    }
    i = i * 10;
    i = i + sdCount[x];
    while (cv){
        string tempSDir;
        cout << "Enter the name of the sub-directory to be created inside '" << temp << "': ";
        cin >> tempSDir;
        int y = searchSDir(tempSDir, x, i);
        if (y != -1)
            cout << "\nSub-Directory already exists!\n";
        else{
            sdirNames[i] = tempSDir;
            sdCount[x]++;
        }
        int tempch;
        cout << "\nPress 1 to create more sub-directories, Press 0 for Main Menu: ";
        cin >> tempch;
        cv = tempch;
        i++;
    }
}

void addFile(){
    int cv = 1;
    string tempDir;
    if (flag == 0){
        cout << "\nPlease create a directory first!\n";
        return;
    }
    cout << "Enter the name of the directory: ";
    cin >> tempDir;
    int x = searchDir(tempDir);
    if (x == -1){
        cout << "\nDirectory does not exist\n";
        return;
    }
    int i = x;
    string tempSDir;
    i = i * 10;
    i = i + sdCount[x];
    cout << "Enter the name of the sub-directory inside '" << tempDir << "': ";
    cin >> tempSDir;
    int y = searchSDir(tempSDir, x, i);
    if (y == -1){
        cout << "\nSub-Directory does not exist\n";
        return;
    }
    int t = y * 10;
    int pos = t + fCount[t];
    while (cv) {
        string tempFile;
        cout << "Enter the name of the file to be created inside '" << tempSDir << "': ";
        cin >> tempFile;
        int z = searchFile(tempFile, t, pos);
        if (z != -1)
            cout << "\nFile already exists\n";
        else {
            fNames[pos] = tempFile;
            fCount[y]++;
        }
        int tempch;
        cout << "\nPress 1 to create more files, Press 0 for Main Menu: ";
        cin >> tempch;
        cv = tempch;
        pos++;
    }
}
void displayDirTree(){
    cout << "\n*****************************************************************************\n";
    cout << "\t||USERNAME: " << root << "||\t\n";
    cout << "*****************************************************************************\n";
    cout << "\tDIRECTORY\tSIZE\tSUB-DIRECTORIES\t\tSIZE\tFILES\n";
    cout << "*****************************************************************************\n";
    for (int i = 0; i < flag; i++){
        cout << "\n\t" << dirNames[i] << "\t\t" << sdCount[i] << "\t";
        if (sdCount[i] == 0)
            cout << "NONE\n";
        else {
            for (int j = i*10; j < sdCount[i]+(i*10); j++){
                cout << sdirNames[j] << "\t\t\t" << fCount[j] << "\t";
                if (fCount[j] == 0)
                    cout << "NONE\n\t\t\t\t";
                else{
                    for (int k = j*10; k < fCount[j]+(j*10); k++){
                        cout << fNames[k] << "\n\t\t\t\t\t\t\t\t";
                    }
                    cout << "\n\t\t\t\t";
                }
            }
        }
    }
    cout << "\n*****************************************************************************\n";
}

int main(){
    cout << "Enter the User Name: ";
    getline(cin, root);
    int ch, x = 1;
    while (x){
        cout << "\nPress 1 to create a directory inside root\n";
        cout << "Press 2 to create a sub-directory inside a directory\n";
        cout << "Press 3 to create a file inside a sub-directory\n";
        cout << "Press 4 to display the directory tree\n";
        cout << "Press 0 to exit\n";
        cin >> ch;
        switch(ch){
            case 0: x = 0;
                    break;
            case 1: addDir();
                    break;
            case 2: addSDir();
                    break;
            case 3: addFile();
                    break;
            case 4: displayDirTree();
        }
    }
    for (int i = 0; i < 1000; i++){
        cout << i+1 << ". " << fNames[i] << endl;
    }
    return 0;
}

 

Output For Two level directory Program in C++

Output for Two level directory Program in C++

In the above program, the main () function is used to take the user name from the user. It is also responsible for taking the choice from the user repeatedly till the user enters 0 for exit. Pressing 1 calls the addDir () method which is used to add a directory inside the root folder. Pressing 2 calls the addSDir () method, which will take the name of the directory inside which a sub-directory has to be created and then the name of the sub-directory and then it will create it inside the respective directory. Pressing 3 will call the addFile () method which will take the name of the directory and sub-directory in which the file is to be created followed by the name of the file and ten it will create the file at the desired location. Pressing 4 will call the displayDirTree () method which will display the directory tree created by the user.

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