Overview of File Processing

There are three steps to writing data to a file:
1. Open the file. If the file doesn’t already exist, it will need to be created.
2. Write the data to the file.
3. Close the file.
Similarly, there are three steps to reading data from a file:
1. Open the file. If the file can’t be opened (for example, if it doesn’t exist), we need
to recognize this and exit gracefully.
2. Read data from the file.
3. Close the file.
When you want to read data from a file, you have choices about how much of the file to
read at a time.We’ll look at each of those choices in detail.
For now, we’ll start at the beginning by opening a file.