APUE/Chapter3: file and I/O
The functions described in this chapter are often referred to as unbuffered I/O(which each read or write invokes a system call in the kernel), in contrast to the standard I/O routines File Descriptors To the kernel, all open files are referred to by file descriptors. A file descriptor is a non-negative integer. When we open an existing file or create a new file, the kernel returns a file descriptor to the process....