本想把原文翻译一遍，一来学习学习Linux的文件系统结构，二来熟悉下专业英语。经历了一个月之久，才翻译到一半。再也没有空闲时间待在学校了，不知道什么时间才能翻译完。先在这里发表一下，给有需要的同志们方便学习，也给自己一个提醒，告诉自己这里还有一件未完成的事。。感謝大家支持

--------------------------------------以下是FHS-2.3正文内容-----------------------------------------------

Filesystem Hierarchy Standard文件系统层次结构标准

Filesystem Hierarchy Standard Group文件系统层次结构标准组

Edited by

Rusty Russell

Daniel Quinlan

Christopher Yeoh

Copyright ? 1994-2004 Daniel Quinlan

Copyright ? 2001-2004 Paul ‘Rusty‘ Russell

Copyright ? 2003-2004 Christopher Yeoh

This standard consists of a set ofrequirements and guidelines for file and directory placement under UNIX-likeoperating systems. The guidelines are intended to support interoperability ofapplications, system administration tools, development tools, and scripts aswell as greater uniformity of documentation for these systems.

这个标准由一组在类UNIX操作系统下的文件和目录如何放置的要求和指南构成。这些指南的目的在于支持这些系统上的应用程序、系统管理工具、开发工具、脚本以及通用文档等之间的互通性。

All trademarks and copyrights are ownedby their owners, unless specifically noted otherwise. Use of a term in thisdocument should not be regarded as affecting the validity of any trademark orservice mark.

除非明确指出，所有的商标权和版权属于他们的拥有者。使用本文中的术语不应该被视为影响任何商标或服务标识的有效性。

Permission is granted to make and distribute verbatim copiesof this standard provided the copyright and this permission notice arepreserved on all copies.

允许制作和分发本标准的完整副本，前提是要求在所有副本上保留此版权和许可声明。

Permission is granted to copy and distribute modifiedversions of this standard under the conditions for verbatim copying, providedalso that the title page is labeled as modified including a reference to theoriginal standard, provided that information on retrieving the originalstandard is included, and provided that the entire resulting derived work isdistributed under the terms of a permission notice identical to this one.

在满足以下条件的情况下，允许拷贝和分发本标准修改后的版本：1.必须是逐字（全部）拷贝；2. 要求在标题页上标明“已修改”并标明引用了本标准；3. 要包含如何取回本标准的信息；4. 所有的衍生的工作成果要按照本标准的许可声明进行发布。

Permission is granted to copy and distribute translationsof this standard into another language, under the above conditions for modifiedversions, except that this permission notice may be stated in a translationapproved by the copyright holder.

在满足上述修改的版本的条件下，允许将本标准拷贝并分发翻译成其他语言的版本。有一点特殊的要求，许可声明的翻译需要经过版权持有人的同意。

Table of Contents

1. Introduction简介

Purpose意图

Conventions约定

2. TheFilesystem文件系统

3. TheRoot Filesystem根文件系统

Purpose目的

Requirements要求

Specific Options特定选项

/bin : Essential usercommand binaries (for use by all users)/bin：必需的用户命令文件（所有的用户都使用）

Purpose目的

Requirements要求

Specific Options特定选项

/boot : Static files of theboot loader/boot：启动加载器的静态文件

Purpose目的

Specific Options特定选项

/dev : Device files/dev：设备文件

Purpose目的

Specific Options特定选项

/etc : Host-specificsystem configuration/etc：特定主机的系统配置

Purpose目的

Requirements要求

Specific Options特定选项

/etc/opt : Configurationfiles for /opt/etc/opt：/opt的配置文件

/etc/X11 : Configurationfor the X Window System (optional)/etc/X11：X窗口系统的配置（可选）

/etc/sgml :Configuration files for SGML (optional)/etc/sgml：SGML的配置文件（可选）

/etc/xml : Configuration files for XML (optional)/etc/xml：XML的配置文件（可选）

/home : User home directories(optional)/home：用户的主目录（可选）

Purpose目的

Requirements要求

/lib : Essential sharedlibraries and kernel modules/lib：必需的共享库和内核模块

Purpose目的

Requirements要求

Specific Options特定选项

/lib<qual> :Alternate format essential shared libraries (optional)/lib：交换格式的必要的共享库（可选）

Purpose目的

Requirements要求

/media : Mount point for removeable media/media：可移动媒体的挂载点

Purpose目的

Specific Options特定选项

/mnt : Mount point for atemporarily mounted filesystem/mnt：临时挂载文件系统的挂载点

Purpose目的

/opt : Add-onapplication software packages/opt：扩展的应用程序软件包

Purpose目的

Requirements要求

/root : Home directory forthe root user (optional)/root：root用户的根目录（可选）

Purpose目的

/sbin : System binaries/sbin：系统工具

Purpose目的

Requirements要求

Specific Options特定选项

/srv : Data for servicesprovided by this system/srv：系统提供的服务的数据

Purpose目的

/tmp : Temporary files/tmp：临时文件

Purpose目的

4. The/usr Hierarchy/usr层次结构

Purpose目的

Requirements要求

Specific Options特定选项

/usr/X11R6 : X WindowSystem, Version 11 Release 6 (optional)/usr/X11R6：X窗口系统，版本11第6次发布（可选）

Purpose目的

Specific Options特定选项

/usr/bin : Most user commands/usr/bin：大多数用户的命令

Purpose目的

Specific Options特定选项

/usr/include :Directory for standard include files./usr/include：标准包含文件的目录

Purpose目的

Specific Options特定选项

/usr/lib : Libraries forprogramming and packages/usr/lib：编程和软件包的库。

Purpose目的

Specific Options特定选项

/usr/lib<qual> :Alternate format libraries (optional)/usr/lib：交换格式的库（可选）

Purpose目的

/usr/local : Local hierarchy/usr/local：本地层次结构

/usr/local/share/usr/local/share

/usr/sbin :Non-essential standard system binaries/非必须的标准系统工具

Purpose目的

/usr/share :Architecture-independent data/usr/share：独立于体系结构的数据

Purpose目的

Requirements要求

Specific Options特定选项

/usr/share/dict : Word lists(optional)/usr/share/dict：单词列表（可选）

/usr/share/man : Manual pages：/usr/share/man：手册页

/usr/share/misc :Miscellaneous architecture-independent data/usr/share/misc：混杂的独立于体系结构的数据

/usr/share/sgml : SGML data(optional)/usr/share/sgml：SGML数据（可选）

/usr/share/xml : XML data (optional)/usr/share/xml：XML数据（可选）

/usr/src : Source code (optional)/usr/src：源代码（可选）

Purpose目的

5. The/var Hierarchy/var层次结构

Purpose目的

Requirements要求

Specific Options特定选项

/var/account : Processaccounting logs (optional)/var/account：处理账户的日志（可选）

Purpose目的

/var/cache : Application cachedata/var/cache：应用程序的高速缓存数据

Purpose目的

Specific Options特定选项

/var/cache/fonts :Locally-generated fonts (optional)/var/cache/fonts：本地生成的字体（可选）

/var/cache/man :Locally-formatted manual pages (optional)/var/cache/man：本地格式化的手册页（可选）

/var/crash : System crash dumps(optional)/var/crash：系统崩溃转储（可选）

Purpose目的

/var/games : Variable game data(optional)/var/games：可变的游戏数据（可选）

Purpose目的

/var/lib : Variable stateinformation/var/lib：可变的状态信息

Purpose目的

Requirements要求

Specific Options特定选项

/var/lib/<editor>: Editor backup files and state (optional)/var/lib/<editor>：编辑器的备份文件和状态（可选）

/var/lib/hwclock :State directory for hwclock (optional)/var/lib/hwclock：硬件时钟的状态目录（可选）

/var/lib/misc :Miscellaneous variable data/var/lib/misc：混杂的可变数据

/var/lock : Lock files/var/lock：锁定的文件

Purpose目的

/var/log : Log files anddirectories/var/log：日志文件和目录

Purpose目的

Specific Options特定选项

/var/mail : User mailbox files(optional)/var/mail：用户的邮箱文件（可选）

Purpose目的

/var/opt : Variable data for /opt/var/opt：/opt中可变的数据

Purpose目的

/var/run : Run-time variable data/var/run：运行时的可变数据

Purpose目的

Requirements要求

/var/spool : Application spooldata/var/spool：应用程序的队列目录（如发送邮件的队列等）。

Purpose目的

Specific Options特定选项

/var/spool/lpd :Line-printer daemon print queues (optional)/var/spool/lpd：打印机守护进程的打印队列工作的目录（可选）

/var/spool/rwho : Rwhod files (optional)/var/spool/rwho：rwho的守护进程的文件（可选）

/var/tmp : Temporaryfiles preserved between system reboots/var/tmp：在系统重启期间保留的临时文件

Purpose目的

/var/yp : NetworkInformation Service (NIS) database files (optional)/var/yp：网络信息服务的数据库文件（可选）

Purpose目的

6. Operating System SpecificAnnex特定操作系统的附件

Linux

/ : Root directory/：根目录

/bin : Essential usercommand binaries (for use by all users)/bin：必要的用户命令工具（所有用户都使用）

/dev : Devices and special files/dev：设备和特定的文件

/etc : Host-specificsystem configuration/etc：特定主机的系统配置

/lib64 and /lib32 : 64/32-bit libraries (architecturedependent)/lib64和/lib32:64/32位库（依赖于体系结构）

/proc : Kernel andprocess information virtual filesystem/proc：内核和进程信息的虚拟文件系统

/sbin : Essential systembinaries/sbin：必要的系统工具

/usr/include : Headerfiles included by C programs/usr/include：C程序包含的头文件

/usr/src : Source code/usr/src：源代码

/var/spool/cron : cron and atjobs/var/spool/cron：cron和jobs

7. Appendix附录

The FHS mailing listFHS邮件列表

Background of the FHSFHS的背景

General Guidelines通用指南

Scope作用域

Acknowledgments感谢

Contributors参与者

Chapter 1. Introduction介绍

Purpose

This standard enables:

·        Software to predict thelocation of installed files and directories, and

·        使软件能够预测被安装的文件和目录的位置，和

·        Users to predict the locationof installed files and directories.

·        使用户能够预测被安装的文件和目录的位置。

We do this by:

·        Specifying guiding principlesfor each area of the filesystem,

·        声明在文件系统中每个区域的指导原则

·        Specifying the minimum filesand directories required,

·        声明需要的最小的文件和目录集合

·        Enumerating exceptions to theprinciples, and

·        列举规则的例外情况，和

·        Enumerating specific caseswhere there has been historical conflict.

·        列举在历史上有冲突的特定情况。

The FHS document is used by:

·        Independent software suppliersto create applications which are FHS compliant, and work with distributionswhich are FHS complaint,

·        独立的软件供应商，其创建的应用程序是FHS兼容的，并和FHS兼容的分发软件一起工作。

·        OS creators to provide systemswhich are FHS compliant, and

·        操作系统创造者，其提供的系统是FHS兼容的。

·        Users to understand andmaintain the FHS compliance of a system.

·        用户，理解并能够维持一个系统中的FHS。

The FHS document has a limited scope:

FHS文档有一个有限的范围：

·        Local placement of local files isa local issue, so FHS does not attempt to usurp system administrators.

·        本地文件在本地如何放置是一个本地的问题，因此FHS并没有试图夺取系统管理权限。

·        FHS addresses issues where fileplacements need to be coordinated between multiple parties such as local sites,distributions, applications, documentation, etc.

·        FHS解决文件放置的协调问题，其包含多个部分，如本地站点、发布、应用程序、文档等等。

Conventions约定

We recommend that you read a typeset version of thisdocument rather than the plain text version. In the typeset version, the namesof files and directories are displayed in a constant-width font.

我们建议你阅读本文档的一个排版后的版本，而不是纯文本。在排版的版本中，文件名和目录名使用等宽字体显示。

Components of filenames that vary are represented by adescription of the contents enclosed in "<"and ">" characters,<thus>. Electronic mail addresses are alsoenclosed in "<" and ">" but are shown in the usualtypeface.

文件名中变化的部分使用"<"和">"字符括起来，例如<thus>。电子邮件地址也使用"<"和">"括起来，但使用了普通字体。

Optional components of filenames are enclosed in "[" and "]"characters and may be combined with the "<"and ">" convention. Forexample, if a filename is allowed to occur either with or without an extension,it might be represented by <filename>[.<extension>].

文件名中可选的部分使用"["和"]"括起来，并且可能和"<"&">"约定组合起来使用。举个例子，如果一个文件名允许出现或者不出现一个扩展名，那么它可以表示为<filename>[.<extension>]。

Variable substrings of directory names and filenames areindicated by "*".

目录名和文件名中的可变的子字符串使用"*"表示。

The sections of the text marked as Rationaleare explanatory and are non-normative.

标记为Rationale的文字部分是解释性的，非规范性的。

Chapter 2. The Filesystem文件系统

This standard assumes that the operating system underlyingan FHS-compliant file system supports the same basic security features found inmost UNIX filesystems.

这个标准假设运行在FHS兼容的文件系统上的操作系统支持基本的安全特性，这些安全特性在大多数UNIX文件系统中都存在。

It is possible to define two independent distinctions amongfiles: shareable vs. unshareable and variable vs. static. In general, filesthat differ in either of these respects should be located in differentdirectories. This makes it easy to store files with different usagecharacteristics on different filesystems.

在多个文件之间，我们可以定义两个相对独立的区别：可共享的与不可共享的，和可变的与不可变的。通常情况下，在以上两个方面中任一个方面有区别的文件都应该被放置在不同的目录中。这使得在不同文件系统上存储具有不同使用特性的文件变得简单。

"Shareable" files are those that can be stored onone host and used on others. "Unshareable" files are those that arenot shareable. For example, the files in user home directories are shareablewhereas device lock files are not.

“可共享”的文件可以被存储在一个主机上并被其他主机使用。“不可共享”的文件不可以被共享。举个例子，用户的主目录是“可共享”的而设备锁文件不是。

"Static" files include binaries, libraries,documentation files and other files that do not change without systemadministrator intervention. "Variable" files are files that are notstatic.

“不变”的文件包括二进制文件、库、文档和其他在系统管理员没有介入的情况下不会改变的文件。“可变”的文件是指不是“不变”的文件。

Chapter 3. The RootFilesystem根文件系统

Purpose目的

The contents of the root filesystem must be adequate toboot, restore, recover, and/or repair the system.

根文件系统的内容必须能够完成启动、还原、恢复以及/或修复系统的工作。

·        To boot a system, enough mustbe present on the root partition to mount other filesystems. This includesutilities, configuration, boot loader information, and other essential start-updata./usr, /opt, and /var are designed such thatthey may be located on other partitions or filesystems.

·        为了启动系统，在根分区上必须有足够的文件以挂载其他文件系统。这包括二进制工具，配置、启动加载器信息，以及其他必要的启动数据。/usr、/opt、和/var被设计为可以被存储在其他分区或文件系统下。

·        To enable recovery and/orrepair of a system, those utilities needed by an experienced maintainer todiagnose and reconstruct a damaged system must be present on the rootfilesystem.

·        为了能够还原以及/或者修复系统，需要一个经验丰富的维护人员使用根文件系统中的那些必须存在的工具来诊断并重建一个被摧毁的系统。

·        To restore a system, thoseutilities needed to restore from system backups (on floppy, tape, etc.) must bepresent on the root filesystem.

·        为了恢复一个系统，需要使用根文件系统中的那些必须存在的工具来从系统备份中恢复系统。

Applications must never create or require special files orsubdirectories in the root directory. Other locations in the FHS hierarchyprovide more than enough flexibility for any package.

应用程序从来都禁止在根目录下创建或者需要创建特殊的文件或者子目录。FHS层次中的其他位置为所有的程序包提供了更多的灵活性。

Requirements要求

The following directories, or symbolic links to directories,are required in /.

下列目录，或者是指向目录的符号链接，是/目录下需要的。

Each directory listed above is specified in detail inseparate subsections below./usr and /var each have acomplete section in this document due to the complexity of those directories.

上面列出的每个目录都在下面用单独的小节详细介绍了。由于/usr和/var目录的复杂性，每个目录都在本文中花了一个完整的章节讲解。

Specific Options特定选项

The following directories, or symbolic links todirectories, must be in /, if the corresponding subsystem isinstalled:

下面的目录或者指向目录的符号链接必须在/目录下存在，如果相应的子系统被安装了：

Each directory listed above is specified in detail inseparate subsections below.

上面列出的每个目录都在下面用单独的小节详细介绍了。

/bin : Essentialuser command binaries (for use by all users) /bin：必要的用户命令工具（所有用户通用）

Purpose目的

/bin contains commandsthat may be used by both the system administrator and by users, but which arerequired when no other filesystems are mounted (e.g. in single user mode). Itmay also contain commands which are used indirectly by scripts.[1]

/bin包含了系统管理员和其他用户都使用的命令，并且要求在没有挂载其他文件系统的情况下也能使用。也包含了能够通过脚本间接使用的命令。[1]

Requirements要求

There must be no subdirectories in /bin./bin目录下禁止有子目录

The following commands, or symbolic links to commands, arerequired in /bin.

下列命令或者到命令的符号链接，需要放在/bin中。

If /bin/sh is not a true Bourne shell, it must be ahard or symbolic link to the real shell command.

如果/bin/sh不是真的Bourne Shell，那么他必须是一个指向真正Shell命令的硬链接或符号链接。

The [ and test commands must be placedtogether in either/bin or /usr/bin.

[和test命令必须放在一起，在/bin目录或/usr/bin目录下。

Specific Options特定选项

The following programs, or symbolic links to programs, mustbe in /bin if the corresponding subsystem is installed:

如果相应的子系统被安装，那么下列程序或者指向程序的符号链接必须存在：

If the gunzip and zcat programs exist, theymust be symbolic or hard links to gzip./bin/csh may be a symbolic linkto /bin/tcsh or /usr/bin/tcsh.

如果gunzip和zcat程序存在，那么它们必须是指向gzip的符号链接或硬链接。/bin/csh可能是一个指向/bin/tcsh或者/usr/bin/tcsh的符号链接。

/boot : Static filesof the boot loader /boot：启动加载器的静态文件

Purpose目的

This directory contains everything required for the bootprocess except configuration files not needed at boot time and the mapinstaller. Thus /boot stores data that is used before the kernel begins executinguser-mode programs. This may include saved master boot sectors and sector mapfiles. [2]

这个目录包含了启动程序所需的所有东西,除了不是在启动阶段需要的配置文件和映射安装器之外。因此,/boot存储了在内核开始执行用户态程序之前所使用的数据。这包括保存的主引导区和区映射文件。[2]

Specific Options特定选项

The operating system kernel must be located in either /or /boot.[3]

操作系统内核必须放置在/或/boot下。[3]

/dev : Device files设备文件

Purpose目的

The /dev directory is the location of special ordevice files.

/dev目录是特殊文件或设备文件的位置。

Specific Options特定选项

If it is possible that devices in /dev will needto be manually created,/dev must contain a command named MAKEDEV,which can create devices as needed. It may also contain aMAKEDEV.localfor any local devices.

如果在/dev下可能存在这样的设备，它们需要被手动创建，那么/dev必须包含一个名为MAKEDEV的命令，此命令可以根据需要创建相应的设备。也应该包含一个对应于本地设备的MAKEDEV.local。

If required, MAKEDEV must have provisions forcreating any device that may be found on the system, not just those that aparticular implementation installs.

如果需要，MAKEDEV必须有创建任意可在系统中查找到的设备的规定，而不仅仅是一个特殊实现的安装程序。

/etc :Host-specific system configuration

/etc：特定主机的系统配置

Purpose目的

The /etc hierarchy contains configuration files. A"configuration file" is a local file used to control the operation ofa program; it must be static and cannot be an executable binary.[4]

/etc层次结构包含了配置文件。一个“配置文件”是一个用来控制程序的操作的本地文件。 它必须是一个静态的文件，并且不能是可执行的二进制文件。

Requirements要求

No binaries may be located under /etc. [5]

/etc目录下不能有可执行文件。[5]

The following directories, or symbolic links to directoriesare required in /etc:

要求在/etc目录下有下列目录或者指向目录的符号链接：

Specific Options特定选项

The following directories, or symbolic links to directoriesmust be in /etc, if the corresponding subsystem is installed:

如果相应的子系统被安装，那么下列在/etc目录下的目录或者指向目录的符号链接必须存在。

The following files, or symbolic links to files, must be in/etc if the corresponding subsystem is installed:[6]

如果相应的子系统被安装，那么下列在/etc目录下的文件或者指向文件的符号链接必须存在。

mtab does not fit thestatic nature of /etc: it is excepted for historical reasons.[7]

mtab并不适用于/etc的静态特性：保留它是出于历史原因。[7]

/etc/opt :Configuration files for /opt /opt的配置文件

Purpose目的

Host-specific configuration files for add-on applicationsoftware packages must be installed within the directory/etc/opt/<subdir>,where <subdir> is the name of the subtree in /opt wherethe static data from that package is stored.

用于扩展应用软件包的特定主机的配置文件必须被安装在/etc/opt/<subdir>这样的目录中，其中<subdir>是/opt中相应的软件包的静态数据存储的路径的子目录树。

Requirements要求

No structure is imposed on the internal arrangement of /etc/opt/<subdir>.

/etc/opt/<subdir>的内部组织没有结构上的要求。

If a configuration file must reside in a different locationin order for the package or system to function properly, it may be placed in alocation other than/etc/opt/<subdir>.

如果一个配置文件必须存在在一个不同的位置以保证该软件包或者系统正常工作，那么它应该放置在某个/etc/opt/<subdir>之外的其他地方。

/etc/X11 : Configurationfor the X Window System (optional)X窗口系统的配置（可选）

Purpose目的

/etc/X11 is the location for all X11 host-specific configuration. Thisdirectory is necessary to allow local control if/usris mounted read only.

/etc/X11是所有的X11特定主机的配置存放的位置。如果/usr以只读方式挂载，那么这个目录是用来允许本地控制所必须的。

Specific Options特定选项

The following files, or symbolic links to files, must be in/etc/X11 if the corresponding subsystem is installed:

下列在/etc/X11中的文件或者指向文件的符号链接必须存在，如果相应的子系统被安装：

Subdirectories of /etc/X11 may include those for xdmand for any other programs (some window managers, for example) that need them.[8] We recommend that window managers with onlyone configuration file which is a default.*wmrc file must name it system.*wmrc(unless there is a widely-accepted alternative name) and not use asubdirectory. Any window manager subdirectories must be identically named tothe actual window manager binary.

/etc/X11的子目录或许会包含xdm以及其它程序（例如某些窗口管理器）所需的文件。[8]我们建议窗口管理器只有一个默认的配置文件。*wmrc文件必须命名为system.*wmrc（除非有一个更为广泛接受的可选名）并且不使用子目录。任意窗口管理器的子目录必须与真实的窗口管理器二进制文件相同的命名。

/etc/sgml :Configuration files for SGML (optional) SGML的配置文件

Purpose目的

Generic configuration files defining high-level parametersof the SGML systems are installed here. Files with names*.confindicate generic configuration files. File with names *.cat are theDTD-specific centralized catalogs, containing references to all other catalogsneeded to use the given DTD. The super catalog filecatalog referencesall the centralized catalogs.

定义了高级SGML系统参数的通用配置文件安装在此处。具有*.conf名字的文件指示了通用的配置文件。具有*.cat名字的文件是特定DTD的集中式目录，包含了使用指定DTD所需要的全部其他目录。这个超级目录文件记录了全部集中式目录的引用。

/etc/xml : Configuration files for XML(optional) XML配置文件（可选）

Purpose目的

Generic configuration files defining high-level parametersof the XML systems are installed here. Files with names*.confindicate generic configuration files. The super catalog file catalogreferences all the centralized catalogs.

定义了高级XML系统参数的通用配置文件安装在此处。具有*.conf名字的文件指示了通用的配置文件。这个超级目录文件记录了全部集中式目录的引用。

/home : User homedirectories (optional)用户主目录（可选）

Purpose目的

/home is a fairly standardconcept, but it is clearly a site-specific filesystem.[9] The setup will differ from host to host.Therefore, no program should rely on this location.[10]

/home是一个公平的标准观点，但是很显然是一个特定站点的文件系统。[9]不同主机之间的安装情况会不一样。因而，不应该有程序依赖于这个位置。[10]

Requirements要求

User specific configuration files for applications arestored in the user‘s home directory in a file that starts with the ‘.‘character (a "dot file"). If an application needs to create more thanone dot file then they should be placed in a subdirectory with a name startingwith a ‘.‘ character, (a "dot directory"). In this case theconfiguration files should not start with the ‘.‘ character.[11]

特定用户的应用程序配置文件保存在用户的主目录下一个以‘.’字符开始命名的文件（一个“点文件”）中。如果一个应用程序需要创建多于一个的点文件，那么它们应该被放置在一个以‘.’字符开始命名的目录（一个“点目录”）中。这种情况下，配置文件不应该以‘.’字符开始命名。[11]

/lib :Essential shared libraries and kernel modules必要的共享库和内核模块

Purpose目的

The /lib directory contains those shared libraryimages needed to boot the system and run the commands in the root filesystem,ie. by binaries in/bin and /sbin. [12]

/lib目录包含了那些共享库的镜像，在启动系统和运行在根文件系统中的命令（即/bin目录和/sbin目录下的二进制程序）时需要这些镜像。

Requirements要求

At least one of each of the following filename patterns arerequired (they may be files, or symbolic links):

至少下列每个文件名模式中至少有一个是必须的（它们或许是文件，或者符号链接）

If a C preprocessor is installed, /lib/cppmust be a reference to it, for historical reasons.[13]

如果安装了一个C预处理器，那么出于历史原因，/lib/cpp必须是一个它的引用。[13]

Specific Options特定选项

The following directories, or symbolic links todirectories, must be in /lib, if the corresponding subsystem isinstalled:

如果相应的子系统被安装了，那么下列目录或者指向目录的符号链接必须在/lib下存在。

/lib<qual>: Alternate format essential shared libraries (optional)交换格式的必须的共享库（可选）

Purpose目的

There may be one or more variants of the /libdirectory on systems which support more than one binary format requiringseparate libraries.[14]

系统中可能有一个或者多个/lib的变体，以支持不同的二进制格式所需的独立的库。[14]

Requirements要求

If one or more of these directories exist, the requirementsfor their contents are the same as the normal/lib directory, exceptthat /lib<qual>/cpp is not required. [15]

如果有一个或者多个这样的目录存在，那么它们的要求和普通/lib目录的要求一样，除了/lib<qual>/cpp不是必须的。[15]

/media : Mount point forremoveable media可移动媒体的挂载点

Purpose目的

This directory contains subdirectories which are used asmount points for removeable media such as floppy disks, cdroms and zip disks.

这个目录包含了这些子目录，它们用来作为软盘、光盘以及压缩磁盘等可移动媒体的挂载点。

Specific Options特定选项

The following directories, or symbolic links todirectories, must be in /media, if the corresponding subsystem isinstalled:

下列目录或者指向目录的符号链接必须在/media下存在，如果相应的子系统被安装：

On systems where more than one device exists for mounting acertain type of media, mount directories can be created by appending a digit tothe name of those available above starting with ‘0‘, but the unqualified namemust also exist.[16]

当挂载的某个特定类型的媒体包含多于一个上述设备时，在这样的系统中，可以以上述可用名字后面添加以‘0’开始的数字作为名字创建相应的挂载目录，但是没有添加数字的目录必须也存在。[16]

/mnt : Mountpoint for a temporarily mounted filesystem临时文件系统的挂载点

Purpose目的

This directory is provided so that the system administratormay temporarily mount a filesystem as needed. The content of this directory isa local issue and should not affect the manner in which any program is run.

提供这个目录是为了系统管理员能够根据需要临时挂载一个文件系统。这个目录的内容是一个本地的问题并且不应该影响到任何程序运行的方式。

This directory must not be used by installation programs: asuitable temporary directory not in use by the system must be used instead.

这个目录在安装程序中禁止被使用：必须使用系统中一个合适的未被使用的临时目录来替代。

/opt : Add-onapplication software packages扩展的应用程序软件包

Purpose目的

/opt is reserved for theinstallation of add-on application software packages.

/opt是保留给扩展应用软件包安装使用的。

A package to be installed in /opt must locate itsstatic files in a separate/opt/<package> or /opt/<provider>directory tree, where <package> is a name that describes thesoftware package and<provider> is the provider‘s LANANAregistered name.

一个要安装到/opt的包必须把它的静态文件放置在独立的/opt/<package>或者/opt/<provider>目录树下，<package>是描述软件包的名字，<provider>是提供者的在Linux指派名称和数字授权（LANANA）注册的名字。

Requirements

The directories /opt/bin, /opt/doc, /opt/include,/opt/info,/opt/lib, and /opt/man are reserved forlocal system administrator use. Packages may provide "front-end" filesintended to be placed in (by linking or copying) these reserved directories bythe local system administrator, but must function normally in the absence ofthese reserved directories.

/opt/bin, /opt/doc,/opt/include, /opt/info,/opt/lib, 以及 /opt/man这些目录保留给本地系统管理员使用。系统管理员可以将软件包提供的一些“前端”文件放置在这些保留的目录（通过链接或者拷贝），但是必要的功能通常可以不需要这些保留的目录。

Programs to be invoked by users must be located in thedirectory /opt/<package>/bin or under the/opt/<provider>hierarchy. If the package includes UNIX manual pages, they must be located in/opt/<package>/share/manor under the /opt/<provider> hierarchy, and the samesubstructure as/usr/share/man must be used.

用户调用的程序必须被防止在/opt/<package>/bin目录下或者在/opt/<provider>层次下。如果这个程序包包含UNIX的手册页面，这些页面必须被放置在/opt/<package>/share/man下或者/opt/<provider>层次下，并且必须使用和/usr/share/man相同的子结构。

Package files that are variable (change in normaloperation) must be installed in/var/opt. See the section on /var/optfor more information.

可变的（正常操作下变化）程序包文件必须安装在/var/opt。更多信息请查看/var/opt一节。

Host-specific configuration files must be installed in /etc/opt.See the section on/etc for more information.

特定主机的配置文件必须安装在/etc/opt。更多信息请查看/etc一节。

No other package files may exist outside the /opt,/var/opt, and/etc/opt hierarchies except for those packagefiles that must reside in specific locations within the filesystem tree inorder to function properly. For example, device lock files must be placed in/var/lockand devices must be located in /dev.

除了一些必须在文件系统树中指定位置以支持程序正常运行的文件以外，程序包的其他文件不应该在/opt、/var/opt和/etc/opt层次以外存在。举例来说，设备锁定文件必须放置在/var/lock，设备文件必须放置在/dev。

Distributions may install software in /opt, butmust not modify or delete software installed by the local system administratorwithout the assent of the local system administrator.

发行版可以在/opt安装软件，但是在未得到本地系统管理员允许的情况下禁止修改或者删除本地系统管理员安装的软件。

/root : Homedirectory for the root user (optional) root用户的主目录（可选）

Purpose目的

The root account‘s home directory may be determined bydeveloper or local preference, but this is the recommended default location.[17]

Root账户的主目录可以由开发者或者本地优选决定，但是这个是建议的默认位置。[17]

/sbin : System binaries系统文件

Purpose目的

Utilities used for system administration (and otherroot-only commands) are stored in/sbin, /usr/sbin, and /usr/local/sbin./sbin contains binaries essential for booting, restoring, recovering,and/or repairing the system in addition to the binaries in/bin. [18] Programs executed after/usr isknown to be mounted (when there are no problems) are generally placed into/usr/sbin.Locally-installed system administration programs should be placed into/usr/local/sbin.[19]

系统管理工具（和其他的仅root命令）存储在/sbin, /usr/sbin, 和/usr/local/sbin下。/sbin包含了除了/bin以外的启动、恢复、重建以及修复系统必需的文件。[18]在/usr挂载之后（没有错误发生）才执行的程序通常被放在/usr/sbin目录下。本地安装的系统管理程序应该被放置在/usr/local/sbin。

Requirements要求

The following commands, or symbolic links to commands, arerequired in /sbin.

下列命令或者指向命令的符号链接要求在/sbin下存在。

Specific Options特定选项

The following files, or symbolic links to files, must be in/sbin if the corresponding subsystem is installed:

下列文件或者指向文件的符号链接必须在/sbin下存在，如果相应的子系统被安装：

/srv : Data forservices provided by this system系统提供的服务的数据

Purpose目的

/srv contains site-specificdata which is served by this system.

/srv包含了当前系统所提供的服务的特定站点的数据。

/tmp : Temporary files临时文件

Purpose目的

The /tmp directory must be made available forprograms that require temporary files.

/tmp目录必须对需要临时文件的程序可用。

Programs must not assume that any files or directories in /tmpare preserved between invocations of the program.

程序不可以假定在/tmp下有任何文件或者目录在多次调用该程序时是保留的。

Chapter 4. The /usr Hierarchy/usr层次结构

Purpose目的

/usr is the second majorsection of the filesystem. /usr is shareable, read-only data. Thatmeans that/usr should be shareable between various FHS-complianthosts and must not be written to. Any information that is host-specific orvaries with time is stored elsewhere.

/usr是文件系统的第二个主要的章节。/usr是可共享的、只读的数据。这意味着/usr在多个可变的FHS兼容的主机之间是可共享的，并且禁止往里写入。任何特定主机的或者随时间变化的信息都应该存放在除/usr之外的其他地方。

Large software packages must not use a direct subdirectoryunder the /usr hierarchy.

大型软件包禁止在/usr层次下直接使用一个子目录。

Requirements要求

The following directories, or symbolic links todirectories, are required in /usr.下列目录或者指向目录的符号链接需要在/usr下存在。

Specific Options特定选项

An exception is made for the X Window System because ofconsiderable precedent and widely-accepted practice.

由于相当多的先例以及被广泛的接受，因此将X窗口系统作为了一个例外。

The following symbolic links to directories may be present.This possibility is based on the need to preserve compatibility with oldersystems until all implementations can be assumed to use the/varhierarchy.

下列指向目录的符号链接可能存在。这种可能性是基于对旧的系统进行兼容的需求，直到可以假定所有的实现都是使用/var层次结构。

    /usr/spool -> /var/spool

    /usr/tmp -> /var/tmp

    /usr/spool/locks -> /var/lock

Once a system no longer requires any one of the abovesymbolic links, the link may be removed, if desired.

一旦一个系统不再需要上述任意一个符号链接，那么如果想要删除相应的连接，就可以进行删除。

/usr/X11R6 : XWindow System, Version 11 Release 6 (optional) X窗口系统，版本11第6次发布

Purpose目的

This hierarchy is reserved for the X Window System, version11 release 6, and related files.

这个层次结构是保留给X窗口系统（版本11，第6次发布）以及相关文件的。

To simplify matters and make XFree86 more compatible withthe X Window System on other systems, the following symbolic links must bepresent if/usr/X11R6 exists:

为了简化问题以及使XFree86与X窗口系统在其他系统上更好的兼容，如果/usr/X11R6存在，那么下列符号链接必须存在：

    /usr/bin/X11 -> /usr/X11R6/bin

    /usr/lib/X11 -> /usr/X11R6/lib/X11

    /usr/include/X11 -> /usr/X11R6/include/X11

In general, software must not be installed or managed viathe above symbolic links. They are intended for utilization by users only. The difficultyis related to the release version of the X Window System — in transitional periods, it is impossible to know what release ofX11 is in use.

通常软件禁止通过上述符号链接进行管理也不能安装在上述符号链接的位置。它们只是用来被用户使用。困难与X窗口系统的发布版本有关——在过渡期内，无法知道在使用X11的什么发布版本。

Specific Options特定选项

Host-specific data in /usr/X11R6/lib/X11 should beinterpreted as a demonstration file. Applications requiring information aboutthe current host must reference a configuration file in/etc/X11,which may be linked to a file in /usr/X11R6/lib. [21]

存放在/usr/X11R6/lib/X11中的特定主机的数据应该理解为演示文件。需要当前主机信息的应用程序必须参考/etc/X11中的一个配置文件，这个配置文件可能链接到一个/usr/X11R6/lib中的文件。[21]

/usr/bin : Most usercommands大多数用户命令

Purpose目的

This is the primary directory of executable commands on thesystem.

这是系统上存放可执行命令的主要的目录。

Specific Options特定选项

The following directories, or symbolic links todirectories, must be in /usr/bin, if the corresponding subsystem isinstalled:

如果相应的子系统被安装，则下列目录或者指向目录的符号链接必须在/usr/bin下存在：

/usr/bin/X11 must be asymlink to /usr/X11R6/bin if the latter exists.

如果后面的存在，那么/usr/bin/X11必须是一个指向/usr/X11R6/bin的符号链接。

The following files, or symbolic links to files, must be in/usr/bin, if the corresponding subsystem is installed:

如果相应的子系统被安装，那么下列文件或者指向文件的符号链接必须在/usr/bin下存在：

/usr/include :Directory for standard include files.标准包含文件的目录

Purpose目的

This is where all of the system‘s general-use include filesfor the C programming language should be placed.

这是所有系统中C程序通用包含文件应该放置的地方。

Specific Options特定选项

The following directories, or symbolic links to directories,must be in /usr/include, if the corresponding subsystem is installed:

如果相应的子系统被安装，那么下列目录或者指向目录的符号链接必须在/usr/include下存在：

The symbolic link /usr/include/X11 must link to /usr/X11R6/include/X11if the latter exists.

符号链接/usr/include/X11必须链接到/usr/X11R6/include/X11，如果后者存在。

/usr/lib :Libraries for programming and packages编程和程序包的库

Purpose目的

/usr/lib includes objectfiles, libraries, and internal binaries that are not intended to be executeddirectly by users or shell scripts.[22]

/usr/lib包含了目标文件、库以及不会被用户或者shell脚本直接执行的内部文件。[22]

Applications may use a single subdirectory under /usr/lib.If an application uses a subdirectory, all architecture-dependent dataexclusively used by the application must be placed within that subdirectory.[23]

应用程序可以在/usr/lib下单独使用一个子目录。如果一个应用程序使用了一个子目录，那么只有该程序使用的体系结构相关的数据必须放置在该子目录下。[23]

Specific Options特定选项

For historical reasons, /usr/lib/sendmail must be asymbolic link to/usr/sbin/sendmail if the latter exists. [24]

出于历史原因，/usr/lib/sendmail必须是一个指向/usr/sbin/sendmail，如果后者存在。[24]

If /lib/X11 exists, /usr/lib/X11 must bea symbolic link to /lib/X11, or to whatever /lib/X11 is asymbolic link to. [25]

如果/lib/X11存在，那么/usr/lib/X11必须是一个符号链接，指向/lib/X11或者符号链接/lib/X11所指向的东西。[25]

/usr/lib<qual>: Alternate format libraries (optional) 交换格式的库（可选）

Purpose目的

/usr/lib<qual>performs the same role as /usr/lib for an alternate binary format,except that the symbolic links/usr/lib<qual>/sendmail and /usr/lib<qual>/X11are not required.[26]

/usr/lib<qual>作为交换二进制的一种格式，行使与/usr/lib相同的角色，但有一点除外，就是/usr/lib<qual>/sendmail和/usr/lib<qual>/X11不是必须的。

/usr/local : Localhierarchy 本地层次结构

Purpose目的

The /usr/local hierarchy is for use by the systemadministrator when installing software locally. It needs to be safe from beingoverwritten when the system software is updated. It may be used for programsand data that are shareable amongst a group of hosts, but not found in /usr.

/usr/local层次结构是系统管理员在本地安装软件时使用的。在系统软件更新时要求它是安全的，不被覆盖。它可以用于在一组主机之间作为可共享的程序和数据，这些程序和数据在/usr中找不到。

Locally installed software must be placed within /usr/localrather than/usr unless it is being installed to replace or upgradesoftware in /usr.[27]

本地安装的软件应该放置在/usr/local而不是/usr，除非它的安装是用来代替或者升级原先处在/usr中的软件。

Requirements要求

The following directories, or symbolic links todirectories, must be in /usr/local

下列目录或者指向目录的符号链接必须在/usr/local下存在：

No other directories, except those listed below, may be in /usr/localafter first installing a FHS-compliant system.

在第一次安装完一个FHS兼容的系统之后，除了那些下面列举出来的目录，不允许其他目录在/usr/local下存在。

Specific Options特定选项

If directories /lib<qual> or /usr/lib<qual>exist, the equivalent directories must also exist in/usr/local.

如果目录/lib<qual> 或者/usr/lib<qual>存在，那么在/usr/local中等价的目录也必须存在。

/usr/local/etc may be asymbolic link to /etc/local.

/usr/local/etc可能是一个指向/etc/local的符号链接。

/usr/local/share

The requirements for the contents of this directory are thesame as /usr/share. The only additional constraint is that/usr/local/share/manand /usr/local/man directories must be synonomous (usually this meansthat one of them must be a symbolic link).[28]

对这个目录的内容的要求与/usr/share相同。仅有的附加约束是/usr/local/share/man和/usr/local/man directories必须是***的（这意味着它们其中的一个必须是符号链接）。[28]

/usr/sbin :Non-essential standard system binaries高级的标准系统工具

Purpose目的

This directory contains any non-essential binaries usedexclusively by the system administrator. System administration programs thatare required for system repair, system recovery, mounting/usr, orother essential functions must be placed in /sbin instead.[29]

/usr/share :Architecture-independent data

Purpose

The /usr/share hierarchy is for all read-only architectureindependent data files.[30]

This hierarchy is intended to be shareable among allarchitecture platforms of a given OS; thus, for example, a site with i386,Alpha, and PPC platforms might maintain a single/usr/share directorythat is centrally-mounted. Note, however, that /usr/share is generallynot intended to be shared by different OSes or by different releases of thesame OS.

Any program or package which contains or requires data thatdoesn‘t need to be modified should store that data in/usr/share (or /usr/local/share,if installed locally). It is recommended that a subdirectory be used in/usr/sharefor this purpose.

Game data stored in /usr/share/games must bepurely static data. Any modifiable files, such as score files, game play logs,and so forth, should be placed in/var/games.

Requirements

The following directories, or symbolic links todirectories, must be in /usr/share

Specific Options

The following directories, or symbolic links todirectories, must be in /usr/share, if the corresponding subsystem isinstalled:

It is recommended that application-specific,architecture-independent directories be placed here. Such directories includegroff,perl, ghostscript, texmf, and kbd (Linux) or syscons(BSD). They may, however, be placed in/usr/lib for backwardscompatibility, at the distributor‘s discretion. Similarly, a/usr/lib/gameshierarchy may be used in addition to the /usr/share/games hierarchy ifthe distributor wishes to place some game data there.

/usr/share/dict : Word lists(optional)

Purpose

This directory is the home for word lists on the system;Traditionally this directory contains only the Englishwords file,which is used by look(1) and various spelling programs.words mayuse either American or British spelling.

Specific Options

The following files, or symbolic links to files, must be in/usr/share/dict, if the corresponding subsystem is installed:

Sites that require both American and British spelling maylink words to-/usr/share/dict/american-english or -/usr/share/dict/british-english.

Word lists for other languages may be added using the Englishname for that language, e.g.,/usr/share/dict/french, /usr/share/dict/danish,etc. These should, if possible, use an ISO 8859 character set which isappropriate for the language in question; if possible the Latin1 (ISO 8859-1)character set should be used (this is often not possible).

Other word lists must be included here, if present.

/usr/share/man : Manualpages

Purpose

This section details the organization for manual pagesthroughout the system, including/usr/share/man. Also refer to thesection on /var/cache/man.

The primary <mandir> of the system is /usr/share/man./usr/share/man contains manual information for commands and data underthe/ and /usr filesystems. [31]

Manual pages are stored in <mandir>/<locale>/man<section>/<arch>.An explanation of<mandir>, <locale>, <section>,and <arch> is given below.

A description of each section follows:

·        man1: User programs Manual pages that describe publicly accessiblecommands are contained in this chapter. Most program documentation that a userwill need to use is located here.

·        man2: System calls This section describes all of the system calls(requests for the kernel to perform operations).

·        man3: Library functions and subroutines Section 3 describes programlibrary routines that are not direct calls to kernel services. This and chapter2 are only really of interest to programmers.

·        man4: Special files Section 4 describes the special files, relateddriver functions, and networking support available in the system. Typically,this includes the device files found in/dev and the kernel interfaceto networking protocol support.

·        man5: File formats The formats for many data files are documented in thesection 5. This includes various include files, program output files, andsystem files.

·        man6: Games This chapter documents games, demos, and generally trivialprograms. Different people have various notions about how essential this is.

·        man7: Miscellaneous Manual pages that are difficult to classify aredesignated as being section 7. The troff and other text processing macropackages are found here.

·        man8: System administration Programs used by system administrators forsystem operation and maintenance are documented here. Some of these programsare also occasionally useful for normal users.

Specific Options

The following directories, or symbolic links todirectories, must be in /usr/share/<mandir>/<locale>,unless they are empty:[32]

The component <section> describes the manualsection.

Provisions must be made in the structure of /usr/share/manto support manual pages which are written in different (or multiple) languages.These provisions must take into account the storage and reference of thesemanual pages. Relevant factors include language (including geographical-baseddifferences), and character code set.

This naming of language subdirectories of /usr/share/manis based on Appendix E of the POSIX 1003.1 standard which describes the localeidentification string — the most well-accepted methodto describe a cultural environment. The<locale> string is:

<language>[_<territory>][.<character-set>][,<version>]

The <language> field must be taken from ISO639 (a code for the representation of names of languages). It must be twocharacters wide and specified with lowercase letters only.

The <territory> field must be the two-lettercode of ISO 3166 (a specification of representations of countries), ifpossible. (Most people are familiar with the two-letter codes used for thecountry codes in email addresses.) It must be two characters wide and specifiedwith uppercase letters only. [33]

The <character-set> field must represent thestandard describing the character set. If the-<character-set>field is just a numeric specification, the number represents the number of theinternational standard describing the character set. It is recommended thatthis be a numeric representation if possible (ISO standards, especially), notinclude additional punctuation symbols, and that any letters be in lowercase.

A parameter specifying a <version> of theprofile may be placed after the-<character-set> field,delimited by a comma. This may be used to discriminate between differentcultural needs; for instance, dictionary order versus a more systems-orientedcollating order. This standard recommends not using the<version>field, unless it is necessary.

Systems which use a unique language and code set for allmanual pages may omit the<locale> substring and store allmanual pages in <mandir>. For example, systems which only haveEnglish manual pages coded with ASCII, may store manual pages (theman<section>directories) directly in /usr/share/man. (That is the traditionalcircumstance and arrangement, in fact.)

Countries for which there is a well-accepted standardcharacter code set may omit the-<character-set> field, but it isstrongly recommended that it be included, especially for countries with severalcompeting standards.

Various examples:

Similarly, provision must be made for manual pages whichare architecture-dependent, such as documentation on device-drivers orlow-level system administration commands. These must be placed under an<arch>directory in the appropriate man<section> directory; forexample, a man page for the i386 ctrlaltdel(8) command might be placed in/usr/share/man/<locale>/man8/i386/ctrlaltdel.8.

Manual pages for commands and data under /usr/localare stored in /usr/local/man. Manual pages for X11R6 are stored in /usr/X11R6/man.It follows that all manual page hierarchies in the system must have the samestructure as/usr/share/man.

The cat page sections (cat<section>)containing formatted manual page entries are also found within subdirectoriesof<mandir>/<locale>, but are not required nor may they bedistributed in lieu of nroff source manual pages.

The numbered sections "1" through "8"are traditionally defined. In general, the file name for manual pages locatedwithin a particular section end with.<section>.

In addition, some large sets of application-specific manualpages have an additional suffix appended to the manual page filename. Forexample, the MH mail handling system manual pages must havemhappended to all MH manuals. All X Window System manual pages must have anxappended to the filename.

The practice of placing various language manual pages inappropriate subdirectories of/usr/share/man also applies to the othermanual page hierarchies, such as/usr/local/man and /usr/X11R6/man.(This portion of the standard also applies later in the section on the optional/var/cache/man structure.)

/usr/share/misc: Miscellaneous architecture-independent data

This directory contains miscellaneousarchitecture-independent files which don‘t require a separate subdirectoryunder/usr/share.

Specific Options

The following files, or symbolic links to files, must be in/usr/share/misc, if the corresponding subsystem is installed:

Other (application-specific) files may appear here, but adistributor may place them in/usr/lib at their discretion. [34]

/usr/share/sgml : SGMLdata (optional)

Purpose

/usr/share/sgml containsarchitecture-independent files used by SGML applications, such as ordinarycatalogs (not the centralized ones, see/etc/sgml), DTDs, entities, orstyle sheets.

Specific Options

The following directories, or symbolic links todirectories, must be in /usr/share/sgml, if the correspondingsubsystem is installed:

Other files that are not specific to a given DTD may residein their own subdirectory.

/usr/share/xml : XML data (optional)

Purpose

/usr/share/xml contains architecture-independentfiles used by XML applications, such as ordinary catalogs (not the centralizedones, see/etc/sgml), DTDs, entities, or style sheets.

Specific Options

The following directories, or symbolic links todirectories, must be in /usr/share/xml, if the corresponding subsystemis installed:

/usr/src : Source code (optional)

Purpose

Source code may be place placed in this subdirectory, onlyfor reference purposes.[35]

Chapter 5. The /var Hierarchy

Purpose

/var contains variabledata files. This includes spool directories and files, administrative andlogging data, and transient and temporary files.

Some portions of /var are not shareable betweendifferent systems. For instance,/var/log, /var/lock, and /var/run.Other portions may be shared, notably/var/mail, /var/cache/man,/var/cache/fonts, and /var/spool/news.

/var is specified here inorder to make it possible to mount /usr read-only. Everything thatonce went into/usr that is written to during system operation (asopposed to installation and software maintenance) must be in/var.

If /var cannot be made a separate partition, it isoften preferable to move/var out of the root partition and into the /usrpartition. (This is sometimes done to reduce the size of the root partition orwhen space runs low in the root partition.) However,/var must not belinked to /usr because this makes separation of/usr and /varmore difficult and is likely to create a naming conflict. Instead, link/varto /usr/var.

Applications must generally not add directories to the toplevel of /var. Such directories should only be added if they have somesystem-wide implication, and in consultation with the FHS mailing list.

Requirements

The following directories, or symbolic links todirectories, are required in /var.

Several directories are `reserved‘ in the sense that theymust not be used arbitrarily by some new application, since they would conflictwith historical and/or local practice. They are:

    /var/backups

    /var/cron

    /var/msgs

    /var/preserve

Specific Options

The following directories, or symbolic links todirectories, must be in /var, if the corresponding subsystem isinstalled:

/var/account :Process accounting logs (optional)

Purpose

This directory holds the current active process accountinglog and the composite process usage data (as used in some UNIX-like systems bylastcommand sa).

/var/cache :Application cache data

Purpose

/var/cache is intended forcached data from applications. Such data is locally generated as a result oftime-consuming I/O or calculation. The application must be able to regenerateor restore the data. Unlike/var/spool, the cached files can bedeleted without data loss. The data must remain valid between invocations ofthe application and rebooting the system.

Files located under /var/cache may be expired inan application specific manner, by the system administrator, or both. Theapplication must always be able to recover from manual deletion of these files(generally because of a disk space shortage). No other requirements are made onthe data format of the cache directories.

Specific Options

/var/cache/fonts: Locally-generated fonts (optional)

Purpose

The directory /var/cache/fonts should be used tostore any dynamically-created fonts. In particular, all of the fonts which areautomatically generated bymktexpk must be located inappropriately-named subdirectories of /var/cache/fonts. [36]

Specific Options

Other dynamically created fonts may also be placed in thistree, under appropriately-named subdirectories of/var/cache/fonts.

/var/cache/man: Locally-formatted manual pages (optional)

Purpose

This directory provides a standard location for sites thatprovide a read-only /usr partition, but wish to allow caching of locally-formattedman pages. Sites that mount/usr as writable (e.g., single-userinstallations) may choose not to use /var/cache/man and may writeformatted man pages into the cat<section> directories in/usr/share/mandirectly. We recommend that most sites use one of the following optionsinstead:

·        Preformat all manual pagesalongside the unformatted versions.

·        Allow no caching of formattedman pages, and require formatting to be done each time a man page is broughtup.

·        Allow local caching offormatted man pages in /var/cache/man.

The structure of /var/cache/man needs to reflectboth the fact of multiple man page hierarchies and the possibility of multiplelanguage support.

Given an unformatted manual page that normally appears in <path>/man/<locale>/man<section>,the directory to place formatted man pages in is/var/cache/man/<catpath>/<locale>/cat<section>,where <catpath> is derived from<path> byremoving any leading usr and/or trailing share pathnamecomponents. (Note that the<locale> component may be missing.) [37]

Man pages written to /var/cache/man may eventuallybe transferred to the appropriate preformatted directories in the sourcemanhierarchy or expired; likewise formatted man pages in the source manhierarchy may be expired if they are not accessed for a period of time.

If preformatted manual pages come with a system onread-only media (a CD-ROM, for instance), they must be installed in the sourcemanhierarchy (e.g. /usr/share/man/cat<section>). /var/cache/manis reserved as a writable cache for formatted manual pages.

/var/crash : System crashdumps (optional)

Purpose

This directory holds system crash dumps. As of the date of thisrelease of the standard, system crash dumps were not supported under Linux butmay be supported by other systems which may comply with the FHS.

/var/games : Variablegame data (optional)

Purpose

Any variable data relating to games in /usr shouldbe placed here. /var/games should hold the variable data previouslyfound in /usr; static data, such as help text, level descriptions, andso on, must remain elsewhere, such as/usr/share/games.

/var/lib : Variablestate information

Purpose

This hierarchy holds state information pertaining to anapplication or the system. State information is data that programs modify whilethey run, and that pertains to one specific host. Users must never need tomodify files in/var/lib to configure a package‘s operation.

State information is generally used to preserve thecondition of an application (or a group of inter-related applications) betweeninvocations and between different instances of the same application. Stateinformation should generally remain valid after a reboot, should not be loggingoutput, and should not be spooled data.

An application (or a group of inter-related applications)must use a subdirectory of/var/lib for its data. There is onerequired subdirectory, /var/lib/misc, which is intended for statefiles that don‘t need a subdirectory; the other subdirectories should only bepresent if the application in question is included in the distribution.[38]

/var/lib/<name> isthe location that must be used for all distribution packaging support.Different distributions may use different names, of course.

Requirements

The following directories, or symbolic links todirectories, are required in /var/lib:

Specific Options

The following directories, or symbolic links todirectories, must be in /var/lib, if the corresponding subsystem isinstalled:

/var/lib/<editor>: Editor backup files and state (optional)

Purpose

These directories contain saved files generated by anyunexpected termination of an editor (e.g.,elvis, jove, nvi).

Other editors may not require a directory for crash-recoveryfiles, but may require a well-defined place to store other information whilethe editor is running. This information should be stored in a subdirectoryunder/var/lib (for example, GNU Emacs would place lock files in /var/lib/emacs/lock).

Future editors may require additional state informationbeyond crash-recovery files and lock files — thisinformation should also be placed under/var/lib/<editor>.

/var/lib/hwclock: State directory for hwclock (optional)

Purpose

This directory contains the file /var/lib/hwclock/adjtime.

/var/lib/misc: Miscellaneous variable data

Purpose

This directory contains variable data not placed in asubdirectory in /var/lib. An attempt should be made to use relatively uniquenames in this directory to avoid namespace conflicts.[39]

/var/lock : Lock files

Purpose

Lock files should be stored within the /var/lockdirectory structure.

Lock files for devices and other resources shared bymultiple applications, such as the serial device lock files that wereoriginally found in either/usr/spool/locks or /usr/spool/uucp,must now be stored in /var/lock. The naming convention which must be usedis "LCK.." followed by the base name of the device. For example, tolock /dev/ttyS0 the file "LCK..ttyS0" would be created.[40]

The format used for the contents of such lock files must bethe HDB UUCP lock file format. The HDB format is to store the processidentifier (PID) as a ten byte ASCII decimal number, with a trailing newline.For example, if process 1230 holds a lock file, it would contain the elevencharacters: space, space, space, space, space, space, one, two, three, zero,and newline.

/var/log : Log filesand directories

Purpose

This directory contains miscellaneous log files. Most logsmust be written to this directory or an appropriate subdirectory.

Specific Options

The following files, or symbolic links to files, must be in/var/log, if the corresponding subsystem is installed:

/var/mail : User mailboxfiles (optional)

Purpose

The mail spool must be accessible through /var/mailand the mail spool files must take the form<username>. [41]

User mailbox files in this location must be stored in thestandard UNIX mailbox format.

/var/opt : Variable datafor /opt

Purpose

Variable data of the packages in /opt must beinstalled in /var/opt/<subdir>, where<subdir> isthe name of the subtree in /opt where the static data from an add-onsoftware package is stored, except where superseded by another file in/etc.No structure is imposed on the internal arrangement of /var/opt/<subdir>.

/var/run : Run-timevariable data

Purpose

This directory contains system information data describingthe system since it was booted. Files under this directory must be cleared(removed or truncated as appropriate) at the beginning of the boot process.Programs may have a subdirectory of/var/run; this is encouraged forprograms that use more than one run-time file.[42] Process identifier (PID) files, which wereoriginally placed in/etc, must be placed in /var/run. Thenaming convention for PID files is<program-name>.pid. Forexample, the crond PID file is named/var/run/crond.pid.

Requirements

The internal format of PID files remains unchanged. Thefile must consist of the process identifier in ASCII-encoded decimal, followedby a newline character. For example, ifcrond was process number 25, /var/run/crond.pidwould contain three characters: two, five, and newline.

Programs that read PID files should be somewhat flexible inwhat they accept; i.e., they should ignore extra whitespace, leading zeroes,absence of the trailing newline, or additional lines in the PID file. Programsthat create PID files should use the simple specification located in the aboveparagraph.

The utmp file, which stores information about whois currently using the system, is located in this directory.

System programs that maintain transient UNIX-domain socketsmust place them in this directory.

/var/spool :Application spool data

Purpose

/var/spool contains datawhich is awaiting some kind of later processing. Data in/var/spoolrepresents work to be done in the future (by a program, user, oradministrator); often data is deleted after it has been processed.[43]

Specific Options

The following directories, or symbolic links todirectories, must be in /var/spool, if the corresponding subsystem isinstalled:

/var/spool/lpd: Line-printer daemon print queues (optional)

Purpose

The lock file for lpd, lpd.lock, must beplaced in /var/spool/lpd. It is suggested that the lock file for eachprinter be placed in the spool directory for that specific printer and namedlock.

Specific Options

/var/spool/rwho : Rwhodfiles (optional)

Purpose

This directory holds the rwhod information for othersystems on the local net.

/var/tmp :Temporary files preserved between system reboots

Purpose

The /var/tmp directory is made available forprograms that require temporary files or directories that are preserved betweensystem reboots. Therefore, data stored in/var/tmp is more persistentthan data in /tmp.

Files and directories located in /var/tmp must notbe deleted when the system is booted. Although data stored in/var/tmpis typically deleted in a site-specific manner, it is recommended thatdeletions occur at a less frequent interval than/tmp.

/var/yp : NetworkInformation Service (NIS) database files (optional)

Purpose

Variable data for the Network Information Service (NIS),formerly known as the Sun Yellow Pages (YP), must be placed in this directory.

Chapter 6.Operating System Specific Annex

This section is for additional requirements andrecommendations that only apply to a specific operating system. The material inthis section should never conflict with the base standard.

Linux

This is the annex for the Linux operating system.

/ : Root directory

On Linux systems, if the kernel is located in /,we recommend using the namesvmlinux or vmlinuz, which havebeen used in recent Linux kernel source packages.

/bin : Essentialuser command binaries (for use by all users)

Linux systems which require them place these additionalfiles into /bin:

·        setserial

/dev : Devices andspecial files

The following devices must exist under /dev.

/dev/null

All data written to this deviceis discarded. A read from this device will return an EOF condition.

/dev/zero

This device is a source ofzeroed out data. All data written to this device is discarded. A read from thisdevice will return as many bytes containing the value zero as was requested.

/dev/tty

This device is a synonym for thecontrolling terminal of a process. Once this device is opened, all reads andwrites will behave as if the actual controlling terminal device had beenopened.

/etc :Host-specific system configuration

Linux systems which require them place these additionalfiles into /etc.

·        lilo.conf

/lib64 and /lib32 : 64/32-bit libraries (architecturedependent)

The 64-bit architectures PPC64, s390x, sparc64 and AMD64must place 64-bit libraries in/lib64, and 32-bit (or 31-bit on s390)libraries in /lib.

The 64-bit architecture IA64 must place 64-bit libraries in/lib.

/proc : Kerneland process information virtual filesystem

The proc filesystem is the de-facto standard Linuxmethod for handling process and system information, rather than/dev/kmemand other similar methods. We strongly encourage this for the storage andretrieval of process information as well as other kernel and memoryinformation.

/sbin : Essentialsystem binaries

Linux systems place these additional files into /sbin.

·        Second extended filesystemcommands (optional):

·        badblocks

·        dumpe2fs

·        e2fsck

·        mke2fs

·        mklost+found

·        tune2fs

·        Boot-loader map installer(optional):

·        lilo

Optional files for /sbin:

·        Static binaries:

·        ldconfig

·        sln

·        ssync

Static ln (sln)and static sync (ssync) are useful when things go wrong. Theprimary use ofsln (to repair incorrect symlinks in /lib aftera poorly orchestrated upgrade) is no longer a major concern now that theldconfigprogram (usually located in /usr/sbin) exists and can act as a guidinghand in upgrading the dynamic libraries. Staticsync is useful in someemergency situations. Note that these need not be statically linked versions ofthe standardln and sync, but may be.

The ldconfig binary isoptional for /sbin since a site may choose to runldconfig atboot time, rather than only when upgrading the shared libraries. (It‘s notclear whether or not it is advantageous to runldconfig on each boot.)Even so, some people like ldconfig around for the following (all toocommon) situation:

·        I‘ve just removed /lib/<file>.

·        I can‘t find out the name ofthe library because ls is dynamically linked, I‘m using a shell thatdoesn‘t havels built-in, and I don‘t know about using "echo *"as a replacement.

·        I have a static sln, butI don‘t know what to call the link.

·        Miscellaneous:

·        ctrlaltdel

·        kbdrate

So as to cope with the fact thatsome keyboards come up with such a high repeat rate as to be unusable,kbdratemay be installed in /sbin on some systems.

Since the default action in thekernel for the Ctrl-Alt-Del key combination is an instant hard reboot, it isgenerally advisable to disable the behavior before mounting the root filesystemin read-write mode. Someinit suites are able to disable Ctrl-Alt-Del,but others may require thectrlaltdel program, which may be installed in/sbin on those systems.

/usr/include :Header files included by C programs

These symbolic links are required if a C or C++ compiler isinstalled and only for systems not based on glibc.

    /usr/include/asm -> /usr/src/linux/include/asm-<arch>

    /usr/include/linux -> /usr/src/linux/include/linux

/usr/src : Source code

For systems based on glibc, there are no specific guidelinesfor this directory. For systems based on Linux libc revisions prior to glibc,the following guidelines and rationale apply:

The only source code that should be placed in a specificlocation is the Linux kernel source code. It is located in/usr/src/linux.

If a C or C++ compiler is installed, but the complete Linuxkernel source code is not installed, then the include files from the kernelsource code must be located in these directories:

    /usr/src/linux/include/asm-<arch>

    /usr/src/linux/include/linux

<arch> is the nameof the system architecture.

/var/spool/cron : cronand at jobs

This directory contains the variable data for the cronand at programs.

Chapter 7. Appendix

The FHS mailing list

The FHS mailing list is located at<freestandards-fhs-discuss@lists.sourceforge.net>. You can subscribe tothe mailing list at this pagehttp://sourceforge.net/projects/freestandards/.

Thanks to Network Operations at the University ofCalifornia at San Diego who allowed us to use their excellent mailing listserver.

As noted in the introduction, please do not send mail tothe mailing list without first contacting the FHS editor or a listedcontributor.

Background of the FHS

The process of developing a standard filesystem hierarchybegan in August 1993 with an effort to restructure the file and directorystructure of Linux. The FSSTND, a filesystem hierarchy standard specific to theLinux operating system, was released on February 14, 1994. Subsequent revisionswere released on October 9, 1994 and March 28, 1995.

In early 1995, the goal of developing a more comprehensiveversion of FSSTND to address not only Linux, but other UNIX-like systems wasadopted with the help of members of the BSD development community. As a result,a concerted effort was made to focus on issues that were general to UNIX-likesystems. In recognition of this widening of scope, the name of the standard waschanged to Filesystem Hierarchy Standard or FHS for short.

Volunteers who have contributed extensively to thisstandard are listed at the end of this document. This standard represents a consensusview of those and other contributors.

General Guidelines

Here are some of the guidelines that have been used in thedevelopment of this standard:

·        Solve technical problems whilelimiting transitional difficulties.

·        Make the specificationreasonably stable.

·        Gain the approval ofdistributors, developers, and other decision-makers in relevant developmentgroups and encourage their participation.

·        Provide a standard that isattractive to the implementors of different UNIX-like systems.

Scope

This document specifies a standard filesystem hierarchy forFHS filesystems by specifying the location of files and directories, and thecontents of some system files.

This standard has been designed to be used by systemintegrators, package developers, and system administrators in the constructionand maintenance of FHS compliant filesystems. It is primarily intended to be areference and is not a tutorial on how to manage a conforming filesystemhierarchy.

The FHS grew out of earlier work on FSSTND, a filesystem organizationstandard for the Linux operating system. It builds on FSSTND to addressinteroperability issues not just in the Linux community but in a wider arenaincluding 4.4BSD-based operating systems. It incorporates lessons learned inthe BSD world and elsewhere about multi-architecture support and the demands ofheterogeneous networking.

Although this standard is more comprehensive than previousattempts at filesystem hierarchy standardization, periodic updates may becomenecessary as requirements change in relation to emerging technology. It is alsopossible that better solutions to the problems addressed here will bediscovered so that our solutions will no longer be the best possible solutions.Supplementary drafts may be released in addition to periodic updates to thisdocument. However, a specific goal is backwards compatibility from one releaseof this document to the next.

Comments related to this standard are welcome. Any commentsor suggestions for changes may be directed to the FHS editor (Daniel Quinlan<quinlan@pathname.com>) or the FHS mailing list. Typographical orgrammatical comments should be directed to the FHS editor.

Before sending mail to the mailing list it is requestedthat you first contact the FHS editor in order to avoid excessive re-discussionof old topics.

Questions about how to interpret items in this document mayoccasionally arise. If you have need for a clarification, please contact theFHS editor. Since this standard represents a consensus of many participants, itis important to make certain that any interpretation also represents theircollective opinion. For this reason it may not be possible to provide animmediate response unless the inquiry has been the subject of previousdiscussion.

Acknowledgments

The developers of the FHS wish to thank the developers,system administrators, and users whose input was essential to this standard. Wewish to thank each of the contributors who helped to write, compile, andcompose this standard.

The FHS Group also wishes to thank those Linux developerswho supported the FSSTND, the predecessor to this standard. If they hadn‘tdemonstrated that the FSSTND was beneficial, the FHS could never have evolved.

Contributors

Notes

Filesystem-Hierarchy-Standard（FHS） 文件系统层次结构标准2.3中英对照版（未完待续）