Buffered Input and Output

Abstract

The UNIX system provides system calls which give direct access to the I/O functions of the kernel however, the efficiency of programmed I/O can be greatly improved by buffering data in the users program and so reducing the number of these calls. In fact, buffered I/O is such a commonly used technique that UNIX provides a complete package called the Standard I/O Libraries to support it. Not only does this package provide a standard I/O interface for programs but it also provides a wide variety of useful functions such as formatted input and output. The use of these libraries is the subject of this chapter.