UNIX System Administration Handbook - Evi Nemeth [14]
System-specific information
Information in this book generally applies to all four of our example systems unless a specific attribution is given. Details particular to one system are marked with the vendor’s logo:
Solaris 2.7
HP-UX 11.00
Red Hat Linux 6.2
FreeBSD 3.4
These logos are used with the permission of their respective owners. However, the vendors have neither reviewed nor endorsed the contents of this book.
1.5 HOW TO USE YOUR MANUALS
The UNIX manuals contain all the information needed to keep the system running, yet that information is sometimes hard to find and often cryptic. You must have access to a complete set of manuals for your version of UNIX. However, that does not necessarily mean that you need to buy printed books. Most documentation is available in electronic form, either as part of the system installation procedure or from the vendor’s web site.
UNIX systems typically come with two types of documentation: “man pages” and supplemental documents. Man pages (so called because they are designed for use with the man command) are concise descriptions of individual commands, file formats, or library routines. They are usually kept on-line but may also be supplied in printed form.
Supplemental documents can include both individual articles and book or pamphlet-length treatments of particular topics. The supplemental materials are not limited to describing just one command, so they can adopt a tutorial or procedural approach. Many pieces of software have both a man page and an article. For example, the man page for vi tells you about the command-line arguments that vi understands, but you have to go to the supplement to learn how to actually edit a file.
Since the man pages are closely tied to the software they describe, vendors tend not to change them very much unless they modify the software itself.3
Not so with the supplements—many vendors have entirely replaced the traditional manuals with new books and documents.
Many of the most important parts of UNIX are maintained by neutral third parties such as the Internet Software Consortium and the Apache Software Foundation. These groups typically provide adequate documentation for the packages they distribute. Vendors sometimes ship the software but skimp on the documentation, so it’s often useful to check back with the original source to see if additional materials are available.
Another useful source of information about the design of many UNIX software packages is the “Request for Comments” document series, which describes the protocols and procedures used on the Internet. See page 263 for more information.
Organization of the man pages
All UNIX systems divide the man pages into sections. However, the exact definition of each section varies among systems. The basic organization of the man pages is shown in Table 1.1.
Table 1.1 Sections of the UNIX man pages
Many systems further subdivide the man pages in each section. For example, section 3m often contains man pages about the system’s math 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.
Most systems allow you to create a section of the manuals called “l” for local man pages. Another common convention is section “n” for software that isn’t strictly local but isn’t standard, either.
troff input for man pages is traditionally kept in the directories /usr/man/manX, where X is a digit 1 through 9, or l or n. Formatted versions of the manuals are kept in /usr/man/catX. The man command will format man pages on the fly; if the cat directories are writable, man will also deposit the formatted pages as they are created, generating a cache of commonly read man pages. You can