How can I search for a employee record (by name) in a text file and only display it's details?

I am making a program where I input the details of many employees and store it in a text file. How can I make a function to search the entire text file and display the only details of that employee and not anyone else's? The details is always being inputted in append mode. I can't use eof() as it will display the entire document.

This is a school project and we have only studied cin and cout and not std::, hence I am using using namespace std;

void hr::menu()
{
    int option, searchopt;

    //................
    cout<<"2. Search Employee"<<endl;      /* By empno, name, dept */
    //.................

    mainopt:
    cout<<"\nChoose your option-";
    cin>>option;

    switch (option)
    {
    //................

    case 2:
        cout<<"1. Search by empno";

        cout<<"\n2. Search by name";
        cout<<"\n3. Search by dept";            
        search:
        cout<<"\n\nChoose your search option-";
        cin>>searchopt;

      switch (searchopt)
        {
            case 1: 
                cout<<"\nEMPNO SEACRH\n";
                empnosearch();
                break;
            case 2:
                cout<<"\nNAME SEARCH\n";
                namesearch();
                break;
            case 3: 
                cout<<"\nDEPARTMENT SEARCH\n";
                deptsearch();
                break;

            default:
            cout<<"Invalid Option. ";
            goto search;
                break;
            }


        break;
             //................

    }
void hr::newemp()       
{
    //declaring all datamembers
        char firstname [30], lastname [30], dept[30]; //etc.

        long localcon;
    int day, month, year;

    ofstream outfile;
    outfile.open ("example.txt",ios::app);

        //inputting all details
        //....................etc.


        //writing details into text file...

        outfile<<"First name:";
    outfile<<firstname;
    outfile<<"\nLast name: ";
    outfile<<lastname;
    outfile<<"\nEmployee no: ";
    outfile<<empnum;

        //...................etc.

        outfile<<"\nLocal Contact: ";
    outfile<<localcon;
    outfile<<"\n\n*************************************************";//indicating end of employee's details
}