Gidday!

This is the code for the book "The Linux Programming Interface"
and this is a note from me, the author, Michael Kerrisk.

For instructions on building the programs, see the file BUILDING.

For notes on changes that have been made to the code since it was
published in the book, see the file CHANGES.


Source code licensing
=====================

All complete programs provided in this distribution are covered by
the GNU General Public License (Version 3), a copy of which is
contained in the file COPYING.gpl-v3, which should have arrived with
this tarball.  The library functions (in the lib/ directory) are
covered by the GNU Lesser General Public License (Version 3); see the
file COPYING.lgpl-v3 provided with this tarball.


A note on the source code
=========================

The source code is available in two versions: "dist" and "book".
The "book" version contains the program source files as published in
the book. The source files in the "dist" version contain extra code
beyond that published in the book. The differences between the "dist"
and "book" versions are as follows:

a) The "dist" versions of some programs contain extra comments.
   These additional comments were stripped out of the printed version
   to make the published versions of the programs shorter. (The book
   itself contains text describing the operation of the programs.)

b) In a few cases, some changes have been incorporated into the
   "dist" versions to make it possible to compile programs on UNIX
   implementations other than Linux, so that you can try them out
   on other implementations if you wish.  Where necessary, the
   additional code is conditionally compiled using the following
   platform-specific macros:

        __linux__       Defined on Linux
        __sun           Defined on Solaris
        __FreeBSD__     Defined on FreeBSD
        __NetBSD__      Defined on NetBSD
        __OpenBSD__     Defined on OpenBSD
        __APPLE__       Defined on Mac OS X
        __hpux          Defined on HP-UX
        __osf__         Defined on Tru64 UNIX (formerly DEC OSF1)
        __sgi           Defined on Irix
        _AIX            Defined on AIX

c) In the "dist" version, some programs have extra functionality beyond
   that in the "book" versions. Where this is significant, comments in
   the programs explain the differences.


Subdirectories
==============

Under the 'tlpi' directory are a number of subdirectories. Each
subdirectory corresponds to one or more chapters of the book.
The following paragraphs give brief notes on the contents of
each subdirectory.

Note that in some cases, files are (hard) linked to appear in more than
one directory. This is particularly the case for each of the files in
the 'lib' directory, most of which are also linked in the directory
of the chapter relating to that file.

Directory       Files for Chapter...

lib             This contains library routines used by other 
                programs. The tlpi_hdr.h and error_functions.* 
                files are located here.
                
progconc        3 (System Programming Concepts)

fileio          4 and 5 (File I/O)

proc            6 (Processes)

memalloc        7 (Memory Allocation)

users_groups    8 (Users and Groups)

proccred        9 (Process Credentials)

time            10 (Time)

syslim          11 (System Limits and Options)

sysinfo         12 (System and Process Information)

filebuff        13 (File I/O Buffering)

filesys         14 (File Systems)

files           15 (File Attributes)

xattr           16 (Extended Attributes)

acl             17 (Access Control Lists)

dirs_links      18 (Directories and Links)

inotify         19 (Monitoring File Events)

signals         20 to 22 (Signals)

timers          23 (Timers and Sleeping)

procexec        24 (Process Creation), 25 (Process Termination),
                26 (Monitoring Child Processes), 27 (Program Execution),
                and 28 (Further Details on Process Creation and Program
                Execution)

threads         29 to 33 (POSIX Threads)

pgsjc           34 (Process Groups, Sessions, and Job Control)

procpri         35 (Process Priorities and Scheduling)

procres         36 (Process Resources)

daemons         37 (Daemons)

cap             39 (Capabilities)

loginacct       40 (Login Accounting)

shlibs          41 and 42 (Shared Libraries)
    
pipes           44 (Pipes and FIFOs)

svipc           45 (System V IPC)
    
svmsg           46 (System V Message Queues)

svsem           47 (System V Semaphores)

svshm           48 (System V Shared Memory)

mmap            49 (Memory Mappings)

vmem            50 (Virtual Memory Operations)

pmsg            52 (POSIX Message Queues)

psem            53 (POSIX Semaphores)

pshm            54 (POSIX Shared Memory)

filelock        55 (File Locking)

sockets         56 to 61 (Sockets and Network Programming)

tty             62 (Terminals)

altio           63 (Alternative I/O Models)

pty             64 (Pseudoterminals)

getopt          Appendix B: Parsing Command-Line Options

In addition, the following supplementary code is included (relating
to topics NOT covered in TLPI):

namespaces      Code examples for namespaces, mainly related to my LWN.net
                article series starting at https://lwn.net/Articles/531114/




最值得阅读学习的 10 个 C 语言开源项目代码
1. Webbench
Webbench是一个在linux下使用的非常简单的网站压测工具。它使用fork()模拟多个客户端同时访问我们设定的URL，测试网站在压力下工作的性能，最多可以模拟3万个并发连接去测试网站的负载能力。Webbench使用C语言编写, 代码实在太简洁，源码加起来不到600行。下载链接： http://home.tiscali.cz/~cz210552/webbench.html

2. Tinyhttpd
tinyhttpd是一个超轻量型Http Server，使用C语言开发，全部代码只有502行(包括注释)，附带一个简单的Client，可以通过阅读这段代码理解一个 Http Server 的本质。下载链接： http://sourceforge.net/projects/tinyhttpd/

3. cJSON
cJSON是C语言中的一个JSON编解码器，非常轻量级，C文件只有500多行，速度也非常理想。

cJSON也存在几个弱点，虽然功能不是非常强大，但cJSON的小身板和速度是最值得赞赏的。其代码被非常好地维护着，结构也简单易懂，可以作为一个非常好的C语言项目进行学习。项目主页: http://sourceforge.net/projects/cjson/

4. CMockery
cmockery是google发布的用于C单元测试的一个轻量级的框架。它很小巧，对其他开源包没有依赖，对被测试代码侵入性小。cmockery的源代码行数不到3K，你阅读一下will_return和mock的源代码就一目了然了。

主要特点：

免费且开源，google提供技术支持；
轻量级的框架，使测试更加快速简单；
避免使用复杂的编译器特性，对老版本的编译器来讲，兼容性好;
并不强制要求待测代码必须依赖C99标准，这一特性对许多嵌入式系统的开发很有用
下载链接： http://code.google.com/p/cmockery/downloads/list

5. Libev
libev是一个开源的事件驱动库，基于epoll，kqueue等OS提供的基础设施。其以高效出名，它可以将IO事件，定时器，和信号统一起来，统一放在事件处理这一套框架下处理。基于Reactor模式，效率较高，并且代码精简（4.15版本8000多行），是学习事件驱动编程的很好的资源。 下载链接： http://software.schmorp.de/pkg/libev.html

6. Memcached
Memcached 是一个高性能的分布式内存对象缓存系统，用于动态Web应用以减轻数据库负载。它通过在内存中缓存数据和对象来减少读取数据库的次数，从而提供动态数据库驱动网站的速度。Memcached 基于一个存储键/值对的 hashmap。Memcached-1.4.7的代码量还是可以接受的，只有10K行左右。下载地址： http://memcached.org/

7. Lua
Lua很棒，Lua是巴西人发明的，这些都令我不爽，但是还不至于脸红，最多眼红。

让我脸红的是Lua的源代码，百分之一百的ANSI C，一点都不掺杂。在任何支持ANSI C编译器的平台上都可以轻松编译通过。我试过，真是一点废话都没有。Lua的代码数量足够小，5.1.4仅仅1.5W行，去掉空白行和注释估计能到1W行。下载地址： http://www.lua.org/

8. SQLite
SQLite是一个开源的嵌入式关系数据库，实现自包容、零配置、支持事务的SQL数据库引擎。 其特点是高度便携、使用方便、结构紧凑、高效、可靠。足够小，大致3万行C代码，250K。 下载地址： http://www.sqlite.org/ 。

9. UNIX v6
UNIX V6 的内核源代码包括设备驱动程序在内 约有1 万行，这个数量的源代码，初学者是能够充分理解的。有一种说法是一个人所能理解的代码量上限为1 万行，UNIX V6的内核源代码从数量上看正好在这个范围之内。看到这里，大家是不是也有“如果只有1万行的话没准儿我也能学会”的想法呢？

另一方面，最近的操作系统，例如Linux 最新版的内核源代码据说超过了1000 万行。就算不是初学者，想完全理解全部代码基本上也是不可能的。下载地址： http://minnie.tuhs.org/cgi-bin/utree.pl?file=V6

10. NETBSD
NetBSD是一个免费的，具有高度移植性的 UNIX-like 操作系统，是现行可移植平台最多的操作系统，可以在许多平台上执行，从 64bit alpha 服务器到手持设备和嵌入式设备。NetBSD计划的口号是：”Of course it runs NetBSD”。它设计简洁，代码规范，拥有众多先进特性，使得它在业界和学术界广受好评。由于简洁的设计和先进的特征，使得它在生产和研究方面，都有卓越的表现，而且它也有受使用者支持的完整的源代码。许多程序都可以很容易地通过NetBSD Packages Collection获得。下载地址： http://www.netbsd.org/

vim
https://github.com/amix/vimrc
make android
https://source.android.com/source/initializing.html
Downloading Android Source
http://source.android.com/source/downloading.html