Specific use of Linux man command

01. Command Overview

Linux provides a rich help manual. When you need to view the parameters of a command, you don’t have to search the Internet, just use man.

You can also use man man to view how to use man.

02. Command format

man [-adfhktwW] [section] [-M path] [-P pager] [-S list] [-m system] [-p string] title…

03. Common options

Usage: man [OPTION...] [section] man page...
 -a, --all find all matching manual pages -d, --debug output debugging information -D, --default reset all options to default values --warnings[=WARNING] turn on groff warnings -f, --whatis equivalent to whatis
 -h displays the syntax and parameter description of man and exits the program after execution.
 -k, --apropos is equivalent to apropos and will search the whatis database for fuzzy search keywords -S, -s, --sections=list uses a colon-separated list of sections -t, --troff uses groff to typeset manual pages -w, --where, --path, --location
               Output the physical location of the manual page -W, --where-cat, --location-cat
               Output the physical location of the cat file -c, --catman Used by catman to correct outdated cat
               Page reformatting -C, --config-file=file Use this user configuration file -K, --global-apropos search for text in all pages
 -M, --manpath=path Set the search path for manual pages to 'path'
 -?, --help give this help list
   --usage give a short usage message
 -V, --version print program version
 -R, --recode=encode output source page encoded in ENCODING
 Find the man page:
 -L, --locale=LOCAL Define the locale to use for this manual page search -m, --systems=SYSTEM use manual pages from other systems
 -e, --extension=extended Limit the search to manual pages with extension type "extended" -i, --ignore-case Do not distinguish between uppercase and lowercase letters when searching manual pages (default)
 -I, --match-case Match uppercase and lowercase letters when searching man pages.

   --regex show all pages matching regex
   --wildcard show all pages matching wildcard

   --names-only makes --regex and --wildcard match page names only,
               not descriptions

04. Related description

4.1 Structure and meaning of man command help information

Structure Name	Representative significance
NAME	Command name and brief description of its function
SYNOPSIS	How to use parameters
DESCRIPTION	A detailed description of the command function, including the meaning of each option
EXAMPLES	Usage examples (with simple instructions)
OVERVIEW	Overview
DEFAULTS	Default functionality
OPTIONS	Specific available options (with descriptions)
ENVIRONMENT	Environment variables
FILES	Used files
SEE ALSO	Related information
HISTORY	Maintenance History and Contact Details

4.2 Overview of man chapters

-S section-list The list is a colon-delimited list of manual pages to search. This option overrides the MANSECT environment variable.
  Some instructions or procedures may have more than one topic, which are located in different sections. So, to view later sections, you can specify here the order in which man should search for sections. The specific segment divisions are as follows:
  Section 1: User commands Section 2: System calls Section 3: Library calls Section 4: Devices Section 5: File formats Section 6: Games Section 7: Miscellaneous Section 8: System commands Section 9: Kernel internal commands Section n: Tcl or Tk commands

4.3 Common keys and their uses in man command

button	usefulness
Spacebar	Scroll down one page
Page down	Scroll down one page
Page up	Go up one page
home	Go directly to the home page
end	Go directly to the last page
/	Search for a keyword from top to bottom, such as "/linux"
?	Search for a keyword from bottom to top, such as "?linux"
n	Locate the next searched keyword
N	Locate the last searched keyword
q	Exit Help Document

05. Reference examples

5.1 User Commands

The whatis command can be used to query what function a command performs and print the query results to the terminal.

[deng@localhost ~]$ whatis cd 
cd (1) - GNU Bourne-Again SHell (GNU Command Interpreter "Bourne II")
cd (3tcl) - change the working directorycd (1p) - change the working directory
[deng@localhost ~]$

From the output above, we can see that the cd command is a built-in command of bash. Its function is to change the current directory. You can view its help in chapters 1 and 1p.

View the bash command, and then search through /cd [deng@localhost ~]$ man 1 cd 
Use the following command to directly view the help information of cd.
[deng@localhost ~]$ man 1p cd

5.2 System calls

[deng@localhost ~]$ man 2 read

5.3 Library calls

[deng@localhost ~]$ man 3 sleep

5.4 Special files (device files)

[deng@localhost ~]$ man 4 tty

5.5 File format (Syntax of configuration files)

[deng@localhost ~]$ man 5 passwd

5.6 Management Commands

[deng@localhost ~]$ man 8 fdisk

The above is the full content of this article. I hope it will be helpful for everyone’s study. I also hope that everyone will support 123WORDPRESS.COM.

You may also be interested in: