Table of contents
Linux commonly used help commands
help command - only applicable to built-in commands
--help command - only applies to external commands
Help commands available internally and externally
Linux shortcut keys
ctrl+shift+plus sign to enlarge the screen
ctrl+minus sign shrink the screen
ctrl+l clear screen
tab completes commands and parameters
ctrl+c terminates the running of the current program
ctrl+d indicates the end of keyboard input
ctrl+a moves the cursor to the beginning of the line
ctrl+e moves the cursor to the end of the line
ctrl+u deletes everything from the cursor to the beginning of the line
ctrl+k deletes everything from the cursor to the end of the line
ctrl+w deletes the word before the cursor
ctrl+r search history commands
Shut down/restart the system
reboot Restart the system
poweroff shut down the system
Linux commonly used help commands
help command - only applicable to built-in commands
Use the format: help name of the built-in command
--help command - only applies to external commands
Use the name of the format external command --help
Help commands available internally and externally
man command
Format: man [Parameter] Command name
The man command is the abbreviation of manual and is used to view help documents for internal/external commands in the system.
The help manual of linux commands is stored in a compressed form under a specific path for everyone to use, saving space.
-a displays all matches
-d displays the path to the help document corresponding to the command, but does not display the document content.
-D displays the path to the help document corresponding to the command and displays the document content
-h displays help information
-f Same as whatis, search for help index information starting with keywords
-C specifies the man command to search for configuration files; the default is man.config
-K searches all manuals for this string
-M specifies the path to search for manuals
-P pro Use pro program to display manual page; default is less
-B pro Use pro program to display HTML man page; default is less
Help document storage path
The /usr/share/man folder stores command help documents. The folder will be partitioned according to different functions of the document.
oil 1
user command
man2
System call command
man3
Some commonly used functions and function libraries (mostly C function libraries)
man4
device file
man5
Configuration file format
man6
game
man7
Miscellaneous
man8
Administrative commands available to system administrators
man9
Files related to the kernel
You can use the whereis command to view the storage path of the help document corresponding to the command.
Man command operation principle
The man command is to decompress the compressed file to a temporary directory, and then use the less program to call the help manual
Therefore, you can use all options of the less command when viewing the help documentation through man.
How to use man
How to operate man
Enter/pagedown
Move down one line
y/pageup
move up one line
space bar
Scroll down one screen
b
Scroll up one screen
?
Function to search up for "string"
/
Ability to drill down for "string"
n
Find what to search for next
q
Exit; browsing to the last page will not automatically exit. You need to enter q to exit.
Paragraph description in the help manual
SYSNOSIS
Usage format description
DESCRIPTION
Detailed description
OPTIONS
Option description
EXAMPLES
Example
FILES
Related documents
AUTHOR
author
COPYRIGHT
Version Information
REPORTING BUGS
BUG information
SEE ALSO
Other help references
info command
Format: info [Parameter] Command name
-k string/--apropos=string Find the string in the corresponding command manual
-d directory/ --directory=directory path Add a directory containing info format help documents
-h/--help Display help information and exit
--index-search=string Go to the node pointed to by the index entry which is a string
-o file path/--output=file path Output the contents of the selected node to the file
-R/--raw-escapes output raw ANSI escape characters (default is)
--no-raw-escapes Output escape characters for text types
--version Show version and exit
-w/--where/--location displays the storage path of the info file corresponding to the command
The help documentation of commands viewed through the info command is more comprehensive. The help documents viewed through the info command are all in info format, but they are also compressed files.
The help document displayed through the info command is easier to understand, and the information displayed is provided in a book-like manner (displayed according to node-chapter classification)
Info format help document storage path
Stored in the /usr/share/info folder
info display content
File: document name
Node: current node (chapter) of the document
Next: The next node (chapter) of the document
Up: The previous node (chapter) of the document
How to operate info
space
Scroll down; after reaching the end of the node, enter the next document node
backspace
Scroll upward; after reaching the top of the node, enter the previous document node
n
Enter the next node at the same level as the current one
p
Enter the previous node of the same level
t
Enter the top node
u
Enter the previous layer (previous level) node
b
Move to the top of this node
i
List all index titles of the document, select one of the titles to enter
m
If the node contains a directory (often the index of the next-level node), a prompt is given to choose to enter.
l (lowercase l)
Go back in browsing history (equivalent to going back in the browser)
