Linux - The man pages

2.3.2. The man pages

A lot of beginning users fear the man (manual) pages, because they are an overwhelming source of documentation. They are, however, very structured, as you will see from the example below on: man man.

Reading man pages is usually done in a terminal window when in graphical mode, or just in text mode if you prefer it. Type the command like this at the prompt, followed by Enter:

yourname@yourcomp ~> man man

The documentation for man will be displayed on your screen after you press Enter:

man(1)                                                         man(1)



NAME
 man - format and display the on-line manual pages
 manpath - determine user's search path for man pages

SYNOPSIS
 man [-acdfFhkKtwW] [--path] [-m system] [-p string] [-C config_file]
 [-M pathlist] [-P pager] [-S section_list] [section] name ...


DESCRIPTION
 man formats and displays the on-line manual pages.  If you specify
 section, man only looks in that section of the manual.  
 name is normally the name of the manual page, which is typically the 
 name of a  command, function, or file.  However, if name contains a 
 slash (/) then man interprets it as a file specification, so that you
 can do man ./foo.5 or even man /cd/foo/bar.1.gz.

 See  below  for  a  description  of where man looks for the manual
 page files.

OPTIONS
 -C  config_file
lines 1-27

Browse to the next page using the space bar. You can go back to the previous page using the b-key. When you reach the end, man will usually quit and you get the prompt back. Type q if you want to leave the man page before reaching the end, or if the viewer does not quit automatically at the end of the page.

	Pagers
	The available key combinations for manipulating the man pages depend on the pager used in your distribution. Most distributions use less to view the man pages and to scroll around. See Section 3.3.4.2 for more info on pagers.

Each man page usually contains a couple of standard sections, as we can see from the man man example:

The first line contains the name of the command you are reading about, and the id of the section in which this man page is located. The man pages are ordered in chapters. Commands are likely to have multiple man pages, for example the man page from the user section, the man page from the system admin section, and the man page from the programmer section.
The name of the command and a short description are given, which is used for building an index of the man pages. You can look for any given search string in this index using the apropos command.
The synopsis of the command provides a technical notation of all the options and/or arguments this command can take. You can think of an option as a way of executing the command. The argument is what you execute it on. Some commands have no options or no arguments. Optional options and arguments are put in between "[" and "]" to indicate that they can be left out.
A longer description of the command is given.
Options with their descriptions are listed. Options can usually be combined. If not so, this section will tell you about it.
Environment describes the shell variables that influence the behavior of this command (not all commands have this).
Sometimes sections specific to this command are provided.
A reference to other man pages is given in the "SEE ALSO" section. In between parentheses is the number of the man page section in which to find this command. Experienced users often switch to the "SEE ALSO" part using the / command followed by the search string SEE and press Enter.
Usually there is also information about known bugs (anomalies) and where to report new bugs you may find.
There might also be author and copyright information.

Some commands have multiple man pages. For instance, the passwd command has a man page in section 1 and another in section 5. By default, the man page with the lowest number is shown. If you want to see another section than the default, specify it after the man command:

man 5 passwd

If you want to see all man pages about a command, one after the other, use the -a to man:

man -a passwd

This way, when you reach the end of the first man page and press SPACE again, the man page from the next section will be displayed.