Question

The ___ member function moves a file's write position to a specified byte in the file.

Short answer

Answer: The seekp() member function is used to move the write position of a file to a specified byte. It is useful when you want to edit specific parts of a file without changing the rest of its content. The syntax for using seekp() is `file_stream_object.seekp(position);`, where 'file_stream_object' is the file stream object you are using to work with the file, and 'position' is the byte index at which the write position will be moved. To modify the content, open the file in read and write mode, move the write position using seekp(), write the new content at the current write position, and then close the file.

Step-by-step solution

Understanding file positions

Whenever we read or write data from/to a file, the position of the file changes. The position refers to the index of the last byte that was accessed. In order to navigate through the file and work on different parts of it, we need a way to change the file's position.

Member function for moving a file's write position

The member function we are discussing is used to move the write position of a file to a specific byte. This is useful when you want to edit specific parts of the file without changing the rest of the content. You simply call this function with the desired byte index as an argument to move the write position to that location.

Syntax for the member function

The syntax for using this member function to move the file's write position to a specific byte is: ```cpp file_stream_object.seekp(position); ``` Here, 'file_stream_object' refers to the file stream object you are using to work with the file, and 'position' is the byte index where the write position will be moved to.

Example of moving the write position

Let's consider an example where we have a file named "example.txt" containing the text "Welcome to the world of programming!". We want to change the word "world" to "zone." Here's how we can do it: 1. Open the file in read and write mode: ```cpp std::fstream file("example.txt", std::ios::in | std::ios::out); ``` 2. Move the write position to the byte where the word "world" starts: ```cpp file.seekp(11); // The word "world" starts at byte index 11 ``` 3. Write the new word, "zone," at the current write position: ```cpp file << "zone"; ``` 4. Close the file: ```cpp file.close(); ``` By following these steps, the file "example.txt" will now contain the text "Welcome to the zone of programming!", with "zone" replacing "world."