Often you need programs that can read information from files or can write results into a file. One such form of program-file communication is file redirection, as you saw in Chapter 8, “Character Input/Output and Redirection.” This method is simple but limited. For example, suppose you want to write an interactive program that asks you for book titles and then saves the complete listing in a file. If you use redirection, as in
books > bklist
your interactive prompts are redirected into bklist. Not only does this put unwanted text into bklist, it prevents you from seeing the questions you are supposed to answer.
Fortunately, C offers more powerful methods of communicating with files. It enables you to open a file from ...