Linux Common commands

Common commands

LS Display files and directories

• -L Display file details (some Linux can be shortened to ll, you can add alias ll= ' Ls-l ' in ~/.BASHRC, and use the source ~/.BASHRC in effect configuration)
• -A View all files (including hidden files)

mkdir Creating a Directory

• -P consecutive creation of multiple directories (ignored if the directory already exists)

CD Switch Directory

Touch Create blank file or modify file time

• -A modify "Access time"
• -M Modify "Change Time"
• -D simultaneous modification of access time and change time
• -T to change into the time [Mm/dd/yy hh:mm]

echo string output to Terminal

Cat View Text File

CP Replication

• -RVF Copy Directory

MV Move or rename

RM Delete

• -R Recursive Delete, can delete subdirectories and files
• -F Force Delete

Find File

Number of lines, words, and bytes of WC statistics text

• -L displays only the number of rows
• -W displays only the number of words
• -C displays only bytes

grep searches for text

RmDir Delete Empty Directory

Tree structure display directory, need to install tree package

PWD Displays the current directory

LN creates a hard link

• -S Create soft links

More, less pagination displays text file contents

Head, tail display file header, tail content

Sed-n "1,5" p/etc/passwd show/etc/passwd 第1-5 Line

Mount Mount

System administration Commands

Stat Displays details of the specified file, more detailed than LS

Who shows current login

WHOAMI Show Current User

Hostname Display host name

UNAME-A Display System Information

Top Monitor the activity and load of the system process

Iotop Monitoring System disk IO (installation required)

PS aux view process and status

Du-h Viewing the directory size

Df-h Viewing disk size

Ifconfig Viewing network status

Ping Test network connectivity

NETSTAT-TUPLN viewing the native port connection status (Ss-ntul more efficient)

Clear Clear Screen

Alias set command Alias

Kill kills the process

Package Compression command

Tar: Packaging compression

• -C Compressed File
• -X Unzip the file
• -T view files within a compressed package
• -Z gzip unzip or compress files
• -j bzip2 unzip or compress files
• -V shows the compression or decompression process V (view)
• -F Target File name
• -C extract to the specified directory

Power off restart

Shutdown-h now, Init 0, Halt, Poweroff shutdown

Shutdown-r, reboot, init 1 restart

Package Management

RPM-IVH Installing the Software

RPM-UVH upgrade Software

RPM-E Uninstalling Software

RPM-QPI Viewing Package description information

RPM-QPL listing the file information for the software

RPM-QF query file belongs to that rpm

Yum Software Warehouse

Centos-yum Package Management

Vim

Three modes of VIM: Command mode, insert mode, edit mode. Use ESC, I, or: Toggle mode

Command mode:

: Q exit

: q! Force exit

: Wq Save and exit

: Set number Displays line numbers

: Set Nonumber hidden line number

: command to execute the command

: integer jumps to the row

/String search string from top to bottom. Press n Next, N prev

DD Clipping cursor Line (6DD clipping 6 lines starting at cursor)

YY the copy cursor is in the row

P Paste

Users and user groups

Useradd Creating a new user

• -D Specify home directory
• -E account expiration date (YYYY-MM-DD)
• -g Specifies an initial user group
• -g specifies one or more extended user groups
• -U Specify user uid

passwd Modifying user passwords

• -L Prohibit Login
• -U Allow Login
• -E Force next logon Change password

USERDEL-RF Delete all user tables

• -F Force deletion of users, home directories and their associated files
• -R Delete users, home directories and their associated files at the same time

Usermod Modifying user Properties

• -d-m used to reassign user's home directory and transfer old data
• -E Account expiry time (YYYY-MM-DD)
• -G Change the owning user group
• -G Change Extended user group
• -L Prohibit Login
• -U Allow Login
• -U Modify user uid

Groupadd Creating a group

/ETC/PASSWD user Account

/etc/group Group account

/etc/shadow Password for user account

Password for/etc/gshadow user group account

File Rights Management

Example:-rw-rw-r--. 1 HT HT 0 May 10:35 1.txt

• The first character "-" denotes a normal file; "l" means a link; "D" means a directory
• The 第2-4 character rw-represents the currently owned user right
• The 第5-7 character rw-represents the currently owned group permission
• 第8-10 character r--represents other user rights

Then the permission for the file is 664

chmod permissions to modify a file or directory. Format: chmod [parameter] permission file or directory name

The Chown command is used to modify a file or directory to belong to the main and owning group. Format: chown [parameter] owner: owning group file or directory name

• The command parameters of chmod and chown are simple----write-R (recursive, modify the properties of all files within the directory) for the directory

Linux Common commands