The concept of file in C++ programming language
- 1. File • File is a collection of related data stored in a particular area on the disk
- 2. Data communication • Data transfer between the console unit and pgm • Data transfer between pgm and the disk file
- 3. If we want use a disk file 1. Suitable name for the file 2. Data type and structure 3. Purpose 4. Opening method
- 4. File name • Is a string of characters • A valid file name • It may contain two parts • Myfile.txt
- 5. Data structure • Crate a file stream using • Ifstream • Ofstream • Fstream • based on purpose
- 6. Purpose/ file modes • ios::app • ios::ate • ios::binary • ios::in • ios::nocreate • ios::noreplace • ios::out • ios::trunc
- 7. Opening a file • Using the constructor of either ifstream ofstream or fstream • Using the member function open()
- 8. Using the constructor of either ifstream ofstream or fstream • Ofstream---create output stream • Ifstream --- create input stream • Fstream----create input/output stream • Initialize the file object with the desired name; • Eg:Ofstream outfile(“result”) • Ifstream infile(“as.cpp”)
- 9. Opening file using open() • File_stream_class stream_object; • Stream_object.open(“file_name”) • Ofstream outfile; • Outfile.open(“myfile”);
- 11. File pointers • Get pointer • Put pointer
- 12. Functions for manipulation file pointers • seekg() • seekp(() • tellg() • tellp()