Logout Exit System
Gedit Text Editor Tools
Uname–r View kernel version information, uname–a more details
Cat/proc/cpuinfo viewing CPUs
Cat/proc/meminfo Viewing memory
Hostname Viewing host names
Ifconfig eth0 view eth0 IP Address
Alias ls= ' ls–ll ' setting aliases
To view the path of the current terminal: TTY
View current Shell:echo $SHELL
All Shell:cat/etc/shells under the current system
View CentOS System hostname Format: Echo $PS 1
Distinguish internal or external commands: Type CD
Which find the location from which the Linux command resides
Ls,cd,type,tty,cat,which,whereis,pwd,echo,mkdir,touch,ln,cp,mv,rm,find,
History View Historical Commands
-A: Append the new reply to the. Bash_history text in the home directory.
-D: Delete the command specified in history; History–d 40
-C: Clears the command history;
View files saved in the history table
Environment variables:
Histsize: Number of records in the command history
Histfile:~/.bash_history
Histfilesize: The number of history records in a command history file
!! : previous order;
Copy, delete, move files or directories
Cp-Copy file or directory
-F: Do not alert when overwriting a file or directory with the same name
-I: Alerts users to confirm when overwriting a file with the same name
-P: Preserve the permissions of the source file while copying, which is the same as the main and time tag attributes
-r: This option must be used when copying directories, which means recursively copying all files and subdirectories
Rm--Delete (remove) file or directory
-F: Delete a file or directory without a reminder, and delete the entire directory tree directly
-I: Remind users to confirm when deleting files or directories
-r: This option must be used when deleting a directory, indicating that the entire directory tree is deleted recursively (should be used sparingly)
Mv-Move File or directory
Find command--locate a file or directory
Query by name: keyword '-name ' find/etc–name ' resol*.conf '
Find by file size: The keyword is: '-size '
Search by file owner: The keyword is '-user '
Search by file type: '-type ' keyword
Du: Statistics directory and space occupancy of files
-A: Count all the files that are included in the disk, not just the statistics directory
-H: Show statistical results in a more humane way
-S: Counts the amount of space occupied by each parameter, rather than counting each subdirectory
Aliases for Commands (alias)
View all aliases under the current user: Alias
Set alias: Alias ls= ' Ls–l '
Alias: Unalias ls
Valid only for the current terminal, if you want to be permanently valid, define it in the configuration file:
Valid only for the current user: ~/.bash
Valid for all users:/ETC/BASHRC
Execution takes effect: source ~/.bash
Date command
Show today for weeks
Date +%a
Set Current system time
Date 0815170115.21
Date +%d Month Day
Date +%f Month Day
Date +%t hours, minutes, seconds
Date +%f-%h-%m-%s
MM: Month
DD: what date
Hh: Hours
Mm: Minutes
Yy: two-digit year
CCYY: four-bit year
. SS: Seconds
Get command Help
The path definition for the shell program to search the executable file is in the PATH environment variable
# echo $PATH
Internal command:
--help
External command:
Help
Hash Cache command
Hash View hit command
Hash–r Clear hit All commands
Shutdown operation
Shutdown–h now
Poweroff
Halt
Init0
Restart operation
Shutdown–r now
Reboot
Init 6
Delay Shutdown or restart operation
Shutdown–r +15 ' The system would be reboot!! ' Shut down after 15 minutes
Bash shortcut keys:
Watch out! The shortcut keys here refer to the terminal, not to the text editor.
Crtl+u: Quickly delete all character contents before the current cursor
Crtl+k: Quickly delete all characters at the end of the line at the current cursor
Crtl+l: Quickly delete the contents of the screen and display the command prompt only in the upper-left corner
Crtl+c: Cancels editing of the current command line and switches to a new line of command prompt
Crtl+a: The current cursor jumps quickly to the beginning of the terminal
Crtl+e: Jumps to the end of the command
Text Search
/keyword:
The string specified by keyword as the keyword, from the current to the end of the file search, case-insensitive
N: Previous
N: Next
? KEYWORD:
The string specified by keyword as the keyword, from the current to the file header search, case-insensitive
N: Previous
N: Next
Command Ls displays a list of files under the specified path
-A: Show all files, including hidden files
-L: Long list form
-H: Unit conversion
-D: Displays the relevant properties of the directory itself, typically used with-L.
-R: Reverse mode display
-R: Recursive display
-rw-r--r--. 1 root root 41364 June Install.log
-,d,l,b,c,p,s
Number 1: Number of times a file has been hard linked
Left Root: Owner of File
Right root: Group of files
41364: Siize of files
June 14 14:32: Last modified time for a file
Install.log: File name
File View commands: Cat, TAC
Cat: Forward
Cat/etc/fstab
Cat/etc/fstab/etc/issue
TAC: Reverse Order
Cat/etc/fstab
Cat/etc/fstab/etc/issue
File content Type view command: File
File/etc/fstab
File/bin/cat
File/dev/sda
Echoing command Echo
Echo "$shell"
Which display the path of the command
which LS
--skip-alias: Disable alias display
User Login Related
Who,whiamai,w
Management class Commands
Mkdir Creating a Directory
-P: Exists and does not error, and can automatically create the required directories
-V: Show more information
-M MODE: Specify permissions directly when creating a directory
Rmdir: Deleting a directory
More, less, command
More/etc/httpd/conf/httpd.conf
Press ENTER to scroll down
Press the B key to turn up one screen
Press Q to exit
Head and tail
Head-4/etc/passwd
Time Stamp management tool for files
Touch
View file Status: Stat
Three time stamps:
Access time: Visited: atime
Modify Time: Modified, abbreviated: Mtime
Change Time: Modified, abbreviated: CTime
2nd Day "Introduction to OS Linux distributions, Getting Started with Linux system basics, Linux command Help, Linux basic Commands"