3.4. System documentation

One of the most important aspects of our administration tasks will be to have the right documentation for our system and installed software. There are numerous sources of information, but we should highlight the following:

a) man is by far the best choice of help. It allows us to consult the GNU/Linux manual, which is grouped into various sections corresponding to administration commands, file formats, user commands, C language calls etc. Normally, to obtain the associated help, we will have enough with:

man command

Every page usually describes the command together with its options and, normally, several examples of use. Sometimes, there may be more than one entry in the manual. For example, there may be a C call with the same name as a command; in this case, we would have to specify what section we want to look at:

man n command

with n being the section number.

There are also several tools for exploring the manuals, for example xman and tkman, which through a graphic interface help to examine the different sections and command indexes. Another interesting command is apropos word, which will allow us to locate man pages that discuss a specific topic (associated with the word).

b) info is another common help system. This program was developed by GNU to document many of its tools. It is basically a text tool where the chapters and pages can be looked up using a simple keyboard-based navigation system.

c) Applications documentation: in addition to certain man pages, it is common to include extra documentation in the applications, in the form of manuals, tutorials or simple user guides. Normally, these documentation components are installed in the directory /usr/share/doc (or /usr/doc depending on the distribution), where normally a directory is created for each application package (normally the application can have a separate documentation package).

d) Distributions' own systems. Red Hat tends to come with several CDs of consultation manuals that can be installed on the system and that come in HTML or PDF formats. Fedora has a documentation project on its webpage. Debian offers its manuals in the form of one more software package that is usually installed in /usr/doc. At the same time, it has tools that classify the documentation in the system, organising it by means of menus for visualisation, such as dwww or dhelp, which offer web interfaces for examining the system's documentation.

e) Finally, X desktops, such as Gnome and KDE, usually also carry their own documentation systems and manuals, in addition to information for developers, whether in the form of graphic help files in their applications or own applications that compile all the help files (for example devhelp in Gnome).