Written primarily for engineers looking to program (better)
at the low level, this book is an ideal teaching tool for
any programmer. Even with the trend toward high-level
development, either through web software (such as PHP) or
managed code (C#), someone still has to write the PHP
interpreter and the C# virtual machine. Linux System
Programming gives you an understanding of core internals
that makes for better code, no matter where it appears in
the stack. Debugging high-level code often requires you to
understand the system calls and kernel behavior of your
operating system, too.

Key topics include:

An overview of Linux, the kernel, the C library, and the C
compiler
Reading from and writing to files, along with other basic
file I/O operations, including how the Linux kernel
implements and manages file I/O
Buffer size management, including the Standard I/O library
Advanced I/O interfaces, memory mappings, and optimization
techniques
The family of system calls for basic process management
Advanced process management, including real-time processes
File and directories-creating, moving, copying, deleting,
and managing them
Memory management -- interfaces for allocating memory,
managing the memory you
have, and optimizing your memory access
Signals and their role on a Unix system, plus basic and
advanced signal interfaces
Time, sleeping, and clock management, starting with the
basics and continuing through POSIX clocks and high
resolution timers