Once, in the early days of UNIX, users had the standard manuals available in print, on their shelves. 9 books were available, each one gigantic and hard to use. Someone eventually had the idea to make it standard to have all of these books on the UNIX system in the form of the man command, where it could be edited easily when new information became available, not to mention the added case of having the manuals searchable and read quickly. These manuals are usually your first target when you have a problem, as nearly every aspect of your system is covered there.
Not only are most commands covered in the online manual, but often configuration files, as well as functions for programming in Linux, can be found. However, many users feel intimidated by man pages because they are often technical in nature and can be difficult to read for newbies. Once you get the hang of reading them, you’ll find that the man pages are the greatest source of help on any system.
man Page Layout or man Command
Manual pages have a very specific format that every official page should follow. To view the main page for a command, use the following syntax for the man program:
$ man < command name > < Enter >
The man program will search through the man path for a man page for the specified command. When it finds the appropriate man page, it displays the page. If no page is found, the man program displays an error message: “No manual entry for < command name >”
Here is a sample documentation for the uname command. To read it, we type:
$ man uname
uname (1) uname (1)
uname – print system information
uname [ OPTION ]…
Print certain system information. With no OPTION, same as -s, -a, -all print all information
-m. machine print the machine (hardware) type
-V prints the operating system version
-help display this help and exit
-version output version information and exit
Written by David Mackenzie.
Report bugs to < firstname.lastname@example.org >.
Copyright C 2000 Free Software Foundation, Inc.
The full documentation for uname is maintained as a Texinfo manual. If the info and uname programs are properly installed at your site, the command
should give you access to the complete manual.
NAME: Here you get a brief description of the command after its official name.
SYNOPSIS: The usage of the command, with optional segments listed in brackets. When the next section is added to it. [ OPTION ] is specified, it means that the command can have the options listed under the next section added to it.
DESCRIPTION: Detailed information about the command, including options that can be options as you want. added to it. Unless specified either here or in the synopsis, you can add as many of these options as you want.
SEE ALSO: This is an important section of the man page that is often overlooked. If the information you are looking for isn’t available on this page, it may be available on one of the pages listed here. Also listed here is information referencing the info command, if that information exists. A description of the info command is in the next section.
Using man works similarly to using less, once you’re reading the page. For more information, try reading the man page for man itself!
Linux, like all the Unix platforms, includes a standardized format for distributing command documentation. The Linux and Unix man page format is a standard file format that can be read and displayed by numerous different utilities.
Next to the command-line man program, the next most common tool for accessing man pages is xman, an X windows-based man page reader. You must be running X windows and a window manager or desktop environment, such as Ghrome or KDE, to use xman. To launch xman, enter the following command at a command prompt while running X windows:
$ xman & < Enter >
Linux will launch xman and display the initial xman window. From this window, you can click on the Help, Quite, or Manual page button. To view a mand page, click your mouse on the main window of xman as shown in the figure.
The xman program will display a list of available man pages in the section click your mouse on the name of a man page to view the specified man page.