The man – manual page reader in Unix/Linux environment

What is man?

Program to read manual of common/installed packages including command, config file or even daemon process.

Why use man?

  • As a comprehensive fast reference to revive your memory; informing you how command, config file, or daemon process ought to be called or used, and also showing accessible options.

  • A profound and exhaustive – and typically in depth technical – portrayal of all parts of the command, config file, or daemon process.

  • To find connection or reference between interrelated programs.

The following are some example syntax of man…

SyntaxDescriptions
$man <command> e.g $man uname
$man <config file>e.g $man ldap.conf
$man <daemon>e.g $man sshd
$man -k <string>list man pages containing <string>
$man -k . -s <section #>list man pages for specific section
$man <section #> <pages>show page from specific section
$whatis <command>show short desc. of a man page
$whereis <command>show location of a package
e.g. result of $man uname

Section

So, what is the #1 in UNAME(1) ? It’s a section number which description’s can be found in $man man.

The following is the complete descriptions of each standard sections.

1   Executable programs or shell commands
2   System calls (functions provided by the kernel)
3   Library calls (functions within program libraries)
4   Special files (usually found in /dev)
5   File formats and conventions eg /etc/passwd
6   Games
7   Miscellaneous (including macro packages and conventions)
    e.g. man(7), groff(7)
8   System administration commands (usually only for root)
9   Kernel routines [Non standard]
Listing available man pages by section number

And what if two different pages in different sections having same name?

Here we go: $man -k ^passwd$

Show specific pages from specific sections

Layout

A normal man page will used certain layout convention for the content formatting. The standard layout would have following sections, thought only NAME section is actually mandatory.

NAMEStandard format consist of comma-separated list of package followed by short description, often a one-liner.
SYNOPSISSummary of the package options
DESCRIPTIONDetails information about the package
and its options.
EXAMPLEList examples of common usability.
SEE ALSOList of related package in alphabetical order.

Example Layout

clear(1)     General Commands Manual     clear(1)

NAME
       clear - clear the terminal screen

SYNOPSIS
       clear

DESCRIPTION
       clear clears your screen if this is possible, including 
       its scrollback buffer (if the extended "E3" capability 
       is defined).  clear looks in the environment for the 
       terminal type and then in the terminfo database to 
       determine how to clear the screen.

       clear ignores any command-line parameters that may be 
       present.

SEE ALSO
       tput(1), terminfo(5)

       This describes ncurses version 6.0 (patch 20160213).

Reference

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