program-file

    #include <bits/stdc++.h>
    #include<fstream>

    using namespace std;

    string LoadFile();
    void CreateFile();
    void Display(string name);
    void Save(string name);
    int CountWords(string name);
    int countChar(string name);
    void FindWord(string name);
    void Empty(string name);
    void input();
    void ReplaceWord(string name);
    void UpperCase();
    void LowerCase();
    void AddFile();
    void Cipher(string name);
    int main()
    {
        string name;
        int number;
        cout << "Ahlan ya user ya hbibi. \nWhat do you like to do today? \n\n";
    while(true){
        cout <<"1-  Load an existing file \n2-  Create a new file \n3-  Display file content \n4-  Save the loaded text to the same file again or different one \n5-  Count the words and the characters in the file\n";
        cout << "6-  Search for a word in a file \n7-  Empty file content \n8-  Add more content to the end of the file \n9-  Replace a word in the file with another word \n10- Turn all the content file to upper case\n";
        cout <<"11- Turn all the content file to lower case \n12- Add another file to the end of the current file \n13- Encrypt and decrypt the file \n14- End\n\n";
        int choice;
        cout << "Enter your choice : ";
        cin >> choice;
        while(choice > 14 || choice<1) cin >> choice;
        if     (choice==1) name =LoadFile();
        else if(choice==2) CreateFile();
        else if(choice==3) Display(name);
        else if(choice==4) Save(name);
        else if(choice==5){ cout << "Number of words = " << CountWords(name) << endl;
                            cout << "Number of Characters = " << countChar(name) << endl << endl;}
        else if(choice==6) FindWord(name);
        else if(choice==7) Empty(name);
        else if(choice==8) input();
        else if(choice==9) ReplaceWord(name);
        else if(choice==10) UpperCase();
        else if(choice==11) LowerCase();
        else if(choice==12) AddFile();
        else if(choice==13) Cipher(name);
        else if(choice==14){ cout << "\nKher ma 3mlt walahy." << endl << endl;
                            break;}
    }
    cout << endl;
        return 0;
    }
    string LoadFile(){
        fstream file;
        char name[81];
        cout << "Enter the file name :";
        cin >> name;
        file.open(name,ios::in);
        if(file.fail()) cout << "\nError!. file not exist\n";
        else  cout << "\nThe file loaded successfully.\n\n";

        return name;
    }
    void Display(string name){
        fstream file;
        char text;
        file.open(name,ios::in);
        cout << endl ;
        while(!file.eof() && !file.fail()){
            file.get(text);
            cout << text;
            }
        cout << endl << endl;
    return;
    }
    void CreateFile(){
        fstream file;
        char name[81];
        cout << "Enter the file name : ";
        cin >> name;
        file.open(name,ios::out);
        cout << "The file created successfully" << endl;
    return;
    }
    void input(){
        fstream file;
        char ch;
        char name[81];
        cout << "Enter the file name : ";
        cin >> name;
        file.open(name,ios::app);
        cout << "End your text , End by ( ~ )" <<endl;
        cout << "Write in the file : ";
        cin.get(ch);
        while(ch!='~'){
        file.put(ch);
        cin.get(ch);
        }
    return;
    }
    int  CountWords(string name){
        fstream file;
        string word;
        int j=0;
        file.open(name,ios::in);
           while(!file.eof() && !file.fail() && file >> word){
             j+=1;
           }
           return j;

    }
    int countChar(string name){
         fstream file;
        char data;
        int i=0;
        file.open(name,ios::in);
        while(!file.eof() && !file.fail() && file >> data){
           if(isalpha(data)){
             i+=1;
           }}
        return i;
    }
    void FindWord(string name){
        fstream file;
        string word, Find;
        int count=0;
        cout<<"enter the word you want to search: ";
        cin>>Find;
         file.open(name,ios::in);
           while(!file.eof()&& !file.fail()){
             file >> word;
             if(word==Find)  count+=1;

    }
       if(count>=1) cout<<"the word is found"<<endl << endl;
       else cout<<"the word is not found"<<endl << endl;
    }
    void Empty(string name){
        fstream file;
        file.open(name,ios::out);
        cout<<"the file is empty successfully" << endl << endl;

    }
    void UpperCase(){
        fstream file;
        char name[81] , ch;
        vector<char> container;
        cout << "Enter the file name : ";
        cin >> name;
        file.open(name,ios::in);
        while(!file.eof() && !file.fail()){
            file.get(ch);
            container.push_back(toupper(ch));
        }
        file.close();
        file.open(name,ios::out);
        for(int i=0 ; i<container.size()-1 ; ++i){
            file.put(container[i]);
        }
        file.close();
    return;
    }
    void LowerCase(){
        fstream file;
        char name[81] , ch;
        vector<char> container;
        cout << "Enter the file name : ";
        cin >> name;
        file.open(name,ios::in);
        while(!file.eof() && !file.fail()){
            file.get(ch);
            container.push_back(tolower(ch));
        }
        file.close();
        file.open(name,ios::out);
        for(int i=0 ; i<container.size()-1 ; ++i){
            file.put(container[i]);
        }
        file.close();
    return;
    }
    void ReplaceWord(string name){
        fstream file , temp;
        char get[50];
        string word , modify;
        cout << "Enter existing word: ";
        cin >> word;
        cout << "Enter new word: ";
        cin >> modify;
        file.open(name,ios::in);
        temp.open("temp.txt",ios::out);
        while(!file.eof() && !file.fail()){
            file.getline(get,50,' ');
            if(get==word) temp << modify << ' ';
            else temp << get << ' ';
    }
        file.close();
        temp.close();
        temp.open("temp.txt",ios::in);
        file.open(name,ios::out);
        while(!temp.eof() && !temp.fail()){
            temp.getline(get,50,' ');
            file << get << ' ';
        }
        return;
        }
    void AddFile(){
        fstream main , add ;
        char name1[81] , name2[81] , ch;
        cout << "Enter The main File : ";
        cin >> name1;
        cout << "Enter The file You want to Add : ";
        cin >>name2;
        main.open(name1,ios::app);
        add.open(name2,ios::in);
        while(!add.eof() && !main.fail() && !add.fail()){
            add.get(ch);
            main.put(ch);
        }
    return;
    }
    void Save(string name){
        fstream load , file;
        char New[81] , ch;
        cout << "Enter the file name you want to save in it : ";
        cin >> New;
        if(New != name){
            load.open(name,ios::in);
            file.open(New,ios::out);
            while(!load.eof() && !load.fail()){
                load.get(ch);
                file.put(ch);

    }}
    cout << "file saved successfully " << endl;
    return;
    }
    void Cipher(string name){
        fstream file,temp ;
        char ch[50] , cipher,word , rep ;
        string sentence;
        file.open(name,ios::in);
        temp.open("temp.txt",ios::out);
        cout << endl;
        while(!file.eof()&&!file.fail() && file >> sentence){
            for (int i=0; i<sentence.length() ;i++){
                if((sentence[i] > 64) && (sentence[i] < 91) || ((sentence[i] > 96) && (sentence[i] < 123)))
                    cipher = (int)sentence[i] + 13;
                else
                    cipher = (int)sentence[i];
                if ((cipher < 0) || (cipher > 122))
                    cipher = cipher - 122 + 96;
                cout << cipher;
                temp << cipher;
            }
            cout << " ";
            temp << " ";
            }
                file.close();
                temp.close();
                temp.open("temp.txt",ios::in);
                file.open(name,ios::out);
                while(!temp.eof() && !temp.fail()){
                        temp.getline(ch,50,' ');
                        file << ch << " ";
                }
            cout << endl << endl;
            return;
    }