The Linux Programming Interface

History and Standards 17 Figure 1-1: Relationships between various UNIX and C standards 1.3.7 Implementation Standards.......... ...

18 Chapter 1 defined the interface that a UNIX implementation must provide in order to be able to call itself System V Release 4 ...

History and Standards 19 integrated into the mainline. For example, version 3 of the Reiserfs journaling file system was part of ...

20 Chapter 1 join him in improving the kernel. Many programmers did so, and, over time, Linux was extended and ported to a wide ...

Chapter 2: Fundamental Concepts This chapter introduces a range of concepts related to Linux system programming. It is intended ...

22 Chapter 2 The Linux kernel executable typically resides at the pathname /boot/vmlinuz, or something similar. The derivation o ...

Fundamental Concepts 23 z Networking: The kernel transmits and receives network messages (packets) on behalf of user processes. ...

24 Chapter 2 doesn’t know where it is located in RAM or, in general, whether a particular part of its memory space is currently ...

Fundamental Concepts 25 Whereas on some operating systems the command interpreter is an integral part of the kernel, on UNIX sys ...

26 Chapter 2 2.3 Users and Groups Each user on the system is uniquely identified, and users may belong to groups. Users Every us ...

Fundamental Concepts 27 2.4 Single Directory Hierarchy, Directories, Links, and Files The kernel maintains a single hierarchical ...

28 Chapter 2 Symbolic links Like a normal link, a symbolic link provides an alternative name for a file. But whereas a normal li ...

Fundamental Concepts 29 A pathname describes the location of a file within the single directory hier- archy, and is either absol ...

30 Chapter 2 write(), close(), and so on) are used to perform I/O on all types of files, including devices. (The kernel translat ...

Fundamental Concepts 31 Filters A filter is the name often applied to a program that reads its input from stdin, per- forms some ...

32 Chapter 2 parent process. The child inherits copies of the parent’s data, stack, and heap seg- ments, which it may then modif ...

Fundamental Concepts 33 z Effective user ID and effective group ID: These two IDs (in conjunction with the supplementary group I ...

34 Chapter 2 Daemon processes A daemon is a special-purpose process that is created and handled by the system in the same way as ...

Fundamental Concepts 35 hard limit, which is a ceiling on the value to which the soft limit may be adjusted. An unprivileged pro ...

36 Chapter 2 Static libraries Static libraries (sometimes also known as archives) were the only type of library on early UNIX sy ...