UNIX/Linux 系统管理技术手册阅读（六）

2021-10-01 03:40:53

2016.8.19 17:20-17:50

HP-UX is based on System V and is tied to Hewlett-Packard’s hardware platforms. It’s closer to the ancestral source tree than either Solaris or AIX, but HP has kept pace with developments in the OS world and has added a variety of its own enhancements. Now that HP has begun supporting Linux as well, the future of HPUX is somewhat less clear.

HP-UX基于System V，并且只用于HP公司的硬件平台。在UNIX族谱上它比Solaris和AIX离源头更近，但是HP一直紧跟操作系统界的发展脚步，给HP-UX加入了各种各样的增强功能。现在HP也开始支持Linux了，HP-UX的未来有点儿不太清晰。

IBM’s AIX started as a variant of Berkeley’s 4.2BSD, but as of version 4 in 1994, most parts of the system migrated to System V. At this point, AIX has drifted rather far from both origins.

IBM的AIX一开始是伯克利4.2BSD的一种变体，但是到1994年的第4版，这个操作系统的大部分都迁移到了System V上面。现在AIX和前面两种源头系统的距离都已经相当遥远了。

In general, we have the impression that AIX has enjoyed less cross-pollination from other systems than most UNIX variants. It also seems to have fallen under the Svengali-like influence of some of IBM’s mainframe and AS/400 operating systems, from which it inherits conventions such as the Object Data Manager (see page 432), the use of configuration commands rather than configuration files, and the SMIT administrative interface. Over time, one might charitably say, it has grown to be more and more like itself.

一般而言，我们对AIX的印象是，比起大多数UNIX变体来说，AIX和其他系统的交流很少。AIX也似乎受到了IBM的大型机和AS/400操作系统某些不好的影响，变得有点强人所难，它从后者那里继承了像ODM、使用配置命令而不是配置文件，以及SMIT管理界面等这样的传统。随着时间的推移，人们或许会厚道地说，AIX已经变得越来越像它自己了。

IBM has been pursuing an interestingly OS-agnostic approach to marketing its hardware for most of the last decade. IBM continues to develop and promote AIX, but it’s also engaged in partnerships with Red Hat and Novell to ensure that their respective Linux distributions run smoothly on IBM hardware. It will be interesting to see how this approach plays out in the years ahead.

在过去10年中的大多数时间里，IBM为营销自己的硬件设备，对操作系统选择一直力求保持一种不明朗的态度，这点显得很有意思。IBM继续开发和推广AIX，但是它也同Red Hat和Novell形成伙伴关系，确保这两家的Linux发行版本能够顺利地运行在IBM的硬件上。静观这样做法在未来几年会带来怎样的效果也挺有意思的。

1.6 SYSTEM-SPECIFIC ADMINISTRATION TOOLS

Modern systems include a variety of visually oriented tools and control panels (such as SUSE’s YaST2 and IBM’s SMIT) that help you configure or administer selected aspects of the system. These tools are useful, especially for novice administrators, but they also tend to be relatively incomplete reflections of the underlying software. They make many administrative tasks easier, but most fall short of being authoritative.

1.6 特定于系统的管理工具

在现代的操作系统内，包含有各种各样可视化的工具和控制面板（比如SUSE的YaST2和IBM的SMIT），帮助用户配置或者管理选定的系统功能。这些工具非常有用，特别是对于管理员新手来说更是如此，但是它们也倾向于不能完整地体现下层软件的实际操作。它们让管理工作变得容易，但大多数又变得不那么权威。

In this book, we cover the underlying mechanisms that the visual tools manipulate rather than the tools themselves, for several reasons. For one, the visual tools tend to be proprietary (or at least, system-specific). They introduce variation into processes that may actually be quite consistent among systems at a lower level. Second, we believe that it’s important for administrators to have an accurate understanding of how their systems work. When the system breaks, the visual tools are often not helpful in tracking down and fixing problems. Finally, manual configuration is often faster, more flexible, more reliable, and easier to script.

在本书中，出于下面几个原因，我们要介绍可视化工具调用的底层机制，而不是工具本身。第一可视化工具趋于专有化（或者至少是趋于为系统所特有）。它们给配置过程带来了变数，而在各个系统之间，这些过程在较低层面实际上可能是相当一致的。第二，我们相信，对于系统管理员来说，准确了解他们的系统是如何工作，这点非常重要。当系统发生故障的时候，可视化工具通常对于确定并修正问题来说没有什么帮助。最后，手工配置往往更好、更快、更灵活、更可靠，而且更易于用脚本实现。

2016.8.21 9:00-9:30

1.7-1.8略

1.9 MAN PAGES AND OTHER ON-LINE DOCUMENTATION

1.9 手册页和其他联机文档

The manual pages, usually called “man pages” because they are read with the man

command, constitute the traditional “on-line” documentation. (Of course, these

days all the documentation is on-line in some form or another.) Man pages are

typically installed with the system. Program-specific man pages come along for

the ride when you install new software packages.

手册页通常称为“man手册页”，因为要用man命令来阅读，它构成了传统的“联机”文档（当然，现如今所有的文档都以这样或者那样的形式在线存在。）man手册页一般伴随系统一起安装。针对特定程序的man手册页通常随着安装新软件包一起安装。

Man pages are concise descriptions of individual commands, drivers, file formats,

or library routines. They do not address more general topics such as “How do I

install a new device?” or “Why is this system so damn slow?” For those questions,

consult your vendor’s administration guides (see page 18) or, for Linux systems,

the documents available from the Linux Documentation Project.

man手册页对单条命令、驱动程序、文件格式或者库例程给出简洁的说明。它们不会解释诸如“我该怎样安装一个新设备？”或者“为什么我们的系统这么慢？”这样更普通的话题。对于这些问题来说，用户可以参考厂商提供的系统管理指南，对于Linux系统来说，也可以从“Linux建档项目（Linux Documentation Project）”中获得文档。

1.9.1 Organization of the man pages

1.9.1 手册页的组织

All systems divide the man pages into sections, but there are minor variations in

the way some sections are defined. The basic schema used by our example systems is shown in Table 1.3.

所有的系统都把man手册分成若干节，但是在各个节的规定上面，不同系统间略有区别。我们的示例系统所采用的基本结果如表1.3所示。

Some sections may be further subdivided. For example, Solaris’s section 3c contains man pages about the system’s standard C library. There is also considerable

variation in the exact distribution of pages; some systems leave section 8 empty

and lump the system administration commands into section 1. A lot of systems

have discontinued games and demos, leaving nothing in section 6. Many systems

have a section of the manuals called “l” (lowercase L) for local man pages.

手册页中有些节会做进一步细分。例如，Solaris的第3c节包含了有关系统C标准库的手册页；有些系统的第8节没有内容，而把系统管理命令放到第1节。许多系统撤销了游戏和演示，第6节什么内容都没有。很多系统在手册中都有一个称为l（L的小写）的节，用于本地手册页。

The exact structure of the sections isn’t important for most topics because man

finds the appropriate page wherever it is stored. You only need to be aware of the

section definitions when a topic with the same name appears in multiple sections.

For example, passwd is both a command and a configuration file, so it has entries

in both section 1 and section 4 or 5.

对于大多数主题而言，各节的确切结构并不重要，因为只要有匹配的手册页，man命令就会找到它。用户只需要对出现在不同节内同名的主题，知道各节的规定就行了。例如，passwd即是一条命令，也是一个配置文件，所以在第一节和第4节或第5节都有关于它的手册项。

1.9.2 man: read man pages

1.9.2 man：读取手册页

man title formats a specific manual page and sends it to your terminal through

more, less, or whatever program is specified in your PAGER environment variable. title is usually a command, device, filename, or name of a library routine.

The sections of the manual are searched in roughly numeric order, although sections that describe commands (sections 1, 8, and 6) are usually searched first.

mantitle命令格式化特定的手册页并通过more、lessw玲，或者在PAGER环境变量中指定的任何程序把手册页发送到用户终端。title通常是一个命令、设备、文件名或者库例程名。手册中各节大致是按照数字顺序进行搜索的，不过通常首先搜索描述命令的那些节（第1、8和6节）。

The form man section title gets you a man page from a particular section. Thus, on most systems, man sync gets you the man page for the sync command, and man 2 sync gets you the man page for the sync system call.

命令格式mansection title可让用户从某个特定的节获取手册页。于是在大多数系统上，man sync命令可得到sync命令的手册页，man 2sync命令可得到系统调用sync的手册页。

Under Solaris, you must preface the section number with the -s flag, for example,

man -s 2 sync.

在Solaris上，必须在节号前面加上-s标志；例如，man -s 2 sync。

man -k keyword or apropos keyword prints a list of man pages that have keyword

in their one-line synopses. For example:

$ man -k translate

objcopy (1) - copy and translate object files

dcgettext (3) - translate message

tr (1) - translate or delete characters

snmptranslate (1) - translate SNMP OID values into more useful information

tr (1p) - translate characters

man -k keyword或者aproposkeyword输出一份手册页清单，在其单行概要中有keyword。例如：