Linux man command - Linux help tutorial

In the beginning, many people restrain to use Linux and one of the reason is they afraid because Linux is a free operating system and doesn't come with warranty and customer's support. Although most people aware that Linux works great with its big potential but that reason seems strong enough to hold them back.

Actually, Linux comes with many great helping tools. We can't say Linux doesn't need customer's support at all but one thing to consider, Linux is the operating system that teach its users. It provides information and helps that user needs within the Linux operating system itself. What I mean is, Linux comes with great tools that user can always refer to whenever they need it. One of the most useful tool to get help in Linux system is the Linux online manual pages.

Linux manual pages

Linux manual page is a great help that comes together with Linux operating system. User can access Linux manual page by invoking man command at the command line interface. Linux man command formats and displays the online Linux manual pages. The Linux manual has 8 standard sections which are:

  1. User Commands
  2. System Calls
  3. C Library Functions
  4. Devices and Special Files
  5. File Formats and Conventions
  6. Games et. Al.
  7. Miscellanea
  8. System Administration tools and Deamons

Linux distributions customize the manual section to their specifics, which often include additional sections.

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

DESCRIPTION
man formats and displays the on-line manual pages. If you specify sec-
tion, 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.

As you can see, Linux man command offers several options for user to specify the details such as provides a specific path, search in specific manual database sections and displays the output in different format. It can also be as simple as it can be, for an example, if you want to just print help on the monitor's screen, then, issue:

[email protected]:~$ man man

That will print the manual page for Linux man command on the screen. You'll see a result similar to the picture below:

Linux man manual page screenshot image

If you perhaps want to copy the man page to a specific file and print the hard copy to read it later, then the command should be:

[email protected]:~$ man man | col -b > /luzar/manual.txt

The | is called pipe and the key location is on the left of the backspace key on your keyboard.

The col -b option is to get a plain text version without backspaces and underscores

The > is called redirection and it means please write in this file I mention here.

The /luzar/manual.txt is the path and the name of the file.

With Linux man command, we can view other commands available in Linux system to learn about that command. Let's say we need help on ls command, we just type man ls and enter:

[email protected]:~$ man ls

In Linux manual page about Linux commands, we can find 3 important information:

  • NAME - Shows the name of the command and a brief information about what it does.
  • SYNOPSIS - Shows the command's syntax and available options that can be used with the command.
  • DESCRIPTION - Explains more about the command.
  • OPTIONS - Available options that can be used with the command. Some commands required option while some can be used with no option. Options enable user to customize the command, change the scope of default value the command offers, and many more depends on the command.
  • TIPS or EXAMPLES - Some commands provide tips and usage examples.
  • AUTHOR - Name of person who writes the command and his email address. (Thank you sir!)
  • SEE ALSO - Related commands.

Here is more information about options available for Linux man command:

man, version 1.6f

usage: man [-adfhktwW] [section] [-M path] [-P pager] [-S list]
[-m system] [-p string] name ...

a : find all matching entries
c : do not use cat file
d : print gobs of debugging information
D : as for -d, but also display the pages
f : same as whatis(1)
h : print this help message
k : same as apropos(1)
K : search for a string in all pages
t : use troff to format pages for printing
w : print location of man page(s) that would be displayed
(if no name given: print directories that would be searched)
W : as for -w, but display filenames only

C file : use `file' as configuration file
M path : set search path for manual pages to `path'
P pager : use program `pager' to display pages
S list : colon separated section list
m system : search for alternate system's man pages
p string : string tells which preprocessors to run
e - [n]eqn(1) p - pic(1) t - tbl(1)
g - grap(1) r - refer(1) v - vgrind(1)

Linux man command examples

You can see some of man command's options which normally used to customize the result in all the examples below.

Linux man command with -a option prints all matching entry:

[email protected]:~$ man -a man
MAN(1) Manual pager utils MAN(1)

NAME
man - an interface to the on-line reference manuals

SYNOPSIS
man [-c|-w|-tZ] [-H[browser]] [-T[device]] [-X[dpi]] [-adhu7V] [-i|-I]
[-m system[,...]] [-L locale] [-p string] [-C file] [-M path] [-P
pager] [-r prompt] [-S list] [-e extension] [--warnings [warnings]]
[[section] page ...] ...
man -l [-7] [-tZ] [-H[browser]] [-T[device]] [-X[dpi]] [-p string] [-P
pager] [-r prompt] [--warnings[warnings]] file ...
man -k [apropos options] regexp ...
man -f [whatis options] page ...

DESCRIPTION
man is the system’s manual pager. Each page argument given to man is
normally the name of a program, utility or function. The manual page
associated with each of these arguments is then found and displayed. A
section, if provided, will direct man to look only in that section of
the manual. The default action is to search in all of the available
sections, following a pre-defined order and to show only the first page
found, even if page exists in several sections.

The example above is the first man result. To see the next manual page, press q to quit the current man. You'll get the menu like in the example below:

[email protected]:~$ man -a man
--Man-- next: man(7) [ view (return) | skip (Ctrl-D) | quit (Ctrl-C) ]

Press enter or return key to view next man result. You can skip the result by pressing ctrl+D. Press ctrl+C to quit. If you press enter, you'll get the next man result like the example below:

MAN(7) Linux Programmer’s Manual MAN(7)

NAME
man - macros to format man pages

SYNOPSIS
groff -Tascii -man file ...

groff -Tps -man file ...

man [section] title

DESCRIPTION
This manual page explains the groff an.tmac macro package (often called
the man macro package). This macro package should be used by develop‐
ers when writing or porting man pages for Linux. It is fairly compati‐
ble with other versions of this macro package, so porting man pages
should not be a major problem (exceptions include the NET-2 BSD
release, which uses a totally different macro package called mdoc; see
mdoc(7)).

That's another result of man command with -a option. Press q to quit the manual page.

This is the example of man command with -k option which can be used to search the short descriptions and manual page names for the keyword mention as regular expression.

[email protected]:~$ man -k mkdir
mkdir (1) - make directories
[email protected]:~$

The man command with -f option can be used to lookup the manual pages referenced by keyword mentioned and print out the short descriptions of any found. See the example below:

[email protected]:~$ man -f less
less (1) - opposite of more
[email protected]:~$

That covers almost all important information you need to know about Linux man command. Linux has many commands and it's impossible to remember all the command options. So, use man command to learn more about new Linux commands everyday.

Back to Linux basic commands main page.

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