Shut down/restart/log out

Common commands	role
shutdown -h now	Immediately shut down
shutdown -h 10	Power off after 10 minutes
shutdown -h 11:00	11:00 shutdown
shutdown -h +10	Scheduled shutdown (after 10 minutes)
shutdown -c	Cancel shutdown at specified time
shutdown -r now	restart
shutdown -r 10	Restart in 10 minutes
shutdown -r 11:00	Time to restart
reboot	restart
init 6	restart
init 0	Immediately shut down
telinit 0	To turn it off
poweroff	Immediately shut down
halt	To turn it off
sync	Buff data synchronization to disk
logout	Logging Out of Shell

View system information and performance

Common commands	role
uname -a	View the kernel, OS, and CPU information
uname -r	Viewing the Kernel Version
uname -m	View processor architecture
arch	View processor architecture
hostname	View computer Name
who	The current login user is displayed
who am i	Displays the login user name
whoami	Displays the current user name
cat /proc/version	View the Linux version information
cat /proc/cpuinfo	Viewing CPU Information
cat /proc/interrupts	View the interrupt
cat /proc/loadavg	Viewing system Load
uptime	View the system running time, number of users, and load
env	View environment variables of the system
lsusb -tv	View USB device information
lspci -tv	View PCI device information
lsmod	View the loaded system modules
grep MemTotal /proc/meminfo	Viewing the Total Memory Capacity
grep MemFree /proc/meminfo	View the amount of free memory
free -m	View the memory usage and swap area usage
date	Displays the system date and time
cal 2021	Displays the 2021 calendar
top	Dynamic display of CPU/memory/process information
vmstat 1 20	System status is collected every second for 20 times
iostat	View the I/O read/write/CPU usage
View the I/O read/write/CPU usage	Query THE CPU usage once every second (10 times)
sar -d 1 10	Querying Disk Performance

Disks and partitions

Common commands	role
fdisk -l	View all disk partitions
swapon -s	View all swap partitions
df -h	View disk usage and mount points
df -hl	Same as above
du -sh /dir	View the size of a specified directory
du -sk * | sort -rn	Displays file and directory sizes from highest to lowest
mount /dev/hda2 /mnt/hda2	Mount the hda2 plate
mount -t ntfs /dev/sdc1 /mnt/usbhd1	Specify file system type mount (such as NTFS)
mount -o loop xxx.iso /mnt/cdrom	Mount the ISO file
umount -v /dev/sda1	Uninstallation by device name
umount -v /mnt/mymnt	Unload via mount points
fuser -km /mnt/hda1	Forced uninstallation (With caution)

Users and user groups

Common commands	role
useradd codesheep	Create a user
userdel -r codesheep	Delete user
usermod -g group_name user_name	Example Modify a user group
usermod -aG group_name user_name	Add a user to a group
Usermod -s /bin/ksh -d /home/codePig -g dev codesheep	Modify the login Shell, home directory, and user group of user codesheep
groups test	View the group of the test user
groupadd group_name	Creating a User Group
groupdel group_name	Deleting a User Group
groupmod -n new_name old_name	Renames a user group
su – user_name	su – user_name
passwd	Change password
passwd codesheep	Example Change the password of a user
w	Viewing Active Users
id codesheep	View information about the specified user codesheep
last	View user login logs
crontab -l	View the scheduled tasks of the current user
cut -d: -f1 /etc/passwd	View all users in the system
cut -d: -f1 /etc/group	View all system groups

Network and process management

Common commands	role
ifconfig	View the attributes of a network interface
ifconfig eth0	View the configuration of a network adapter
route -n	Viewing the Routing Table
netstat -lntp	View all listening ports
netstat -antp	View established TCP connections
netstat -lutp	View the TCP/UDP status
ifup eth0	Example Enable the eth0 network device
ifdown eth0	The eth0 network device is disabled
iptables -L	View iptables rules
Ifconfig eth0 192.168.1.1 netmask 255.255.255.0	Configuring the IP Address
dhclient eth0	Enable eth0 in DHCP mode
route add -net 0/0 gw Gateway_IP	Configuring the Default Gateway
Route add-net 192.168.0.0 netmask 255.255.0.0 GW 192.168.1.1	Configure static route to network ‘192.168.0.0/16’
route del 0/0 gw Gateway_IP	Deleting a Static Route
hostname	Viewing host Names
host www.baidu.com	Resolving host names
nslookup www.baidu.com	Query DNS records to check whether domain name resolution is normal
ps -ef	Viewing All Processes
ps -ef | grep codesheep	Filter out the processes you need
kill -s name	Kill Specifies the name of the process
kill -s pid	Kill Specifies the PID process
top	Displays process status in real time
vmstat 1 20	System status is collected every second for 20 times
iostat	iostat
sar -u 1 10	Query THE CPU usage once every second (10 times)
sar -d 1 10	Querying Disk Performance

Common system service commands

Common commands	role
chkconfig –list	List system services
Service < service name > status	Viewing a service
Service < service name > start	Start a service
Service < service name > stop	Terminate a service
Service < service name > restart	Restarting a service
Systemctl status < service name >	Viewing a service
Systemctl start < service name >	Start a service
Systemctl stop	Terminate a service
Systemctl restart	Restarting a service
Systemctl enable	Turn off autostart
Systemctl disable < service name >	Turn off autostart

File and directory operations

Common commands	role
CD < directory name >	Go to a directory
cd ..	Back to parent directory
cd .. /..	Go back two levels of directory
cd	Go to your personal home directory
cd –	Go back to the directory of the previous step
pwd	Display current path
ls	View the file directory list
ls -F	View the contents of a directory (is it a file or a directory?)
ls -l	View a detailed list of files and directories
ls -a	View hidden files
ls -lh	View detailed lists of files and directories (to improve file size readability)
ls -lSr	View a list of files and directories (in ascending file size)
tree	View the tree structure of files and directories
Mkdir < directory name >	Create a directory
mkdir dir1 dir2	Create two directories simultaneously
mkdir -p /tmp/dir1/dir2	Creating a directory tree
rm -f file1	Delete the ‘file1’ file
rmdir dir1	Delete the ‘dir1’ directory
rm -rf dir1	Delete the ‘dir1’ directory and its contents
rm -rf dir1 dir2	Delete both directories and their contents simultaneously
mv old_dir new_dir	Rename/move the directory
cp file1 file2	Copy the file
cp dir/* .	Copy all files in a directory to the current directory
cp -a dir1 dir2	Copy directory
cp -a /tmp/dir1 .	Copy a directory to the current directory
ln -s file1 link1	Create soft links to files/directories
ln file1 lnk1	Create a physical link to a file/directory
find / -name file1	Search files/directories from the following directory
find / -user user1	Search for the files/directories of user user1
find /dir -name *.bin	Search for files with the. Bin suffix in directory /dir
Locate < key words >	Quick File Location
locate *.mp4	Look for files at the end of.MP4
Whereis < keyword >	Displays the path to a binary/executable file
Which < key words >	Find a binary file in the system directory
chmod ugo+rwx dir1	Set the read (r) write (W) execute (X) permissions of the directory owner (u), group (G), and others (O)
chmod go-rwx dir1	Remove the read/write permissions of groups (g) and others (O) on directories
chown user1 file1	Change the owner attribute of a file
chown -R user1 dir1	Change the owner attribute of a directory
chgrp group1 file1	Changing file Groups
chown user1:group1 file1	Change the owner and group of the file

File viewing and processing

Common commands	role
cat file1	Viewing file Contents
cat -n file1	View the content and indicate the number of lines
tac file1	Look back at the file from the last line
more file1	more file1
less file1	Similar to the more command, but allows the reverse operation
head -2 file1	Look at the first two lines of the file
tail -2 file1	Look at the last two lines of the file
tail -f /log/msg	View the content added to the file in real time
grep codesheep hello.txt	Look for the keyword codesheep in the file hello.txt
grep ^sheep hello.txt	Look in the file hello.txt for anything that begins with sheep
grep [0-9] hello.txt	Select all the lines in the hello.txt file that contain numbers
sed ‘s/s1/s2/g’ hello.txt	Replace s1 with S2 in hello.txt
sed ‘/^$/d’ hello.txt	Remove all blank lines from the hello.txt file
sed ‘/ *#/d; /^$/d’ hello.txt	Remove all comments and blank lines from the hello.txt file
sed -e ‘1d’ hello.txt	Exclude the first line from the file hello.txt
sed -n ‘/s1/p’ hello.txt	View the row that contains only the keyword “s1”
sed -e ‘s/ *$//’ hello.txt	Remove the whitespace character at the end of each line
sed -e ‘s/s1//g’ hello.txt	Remove only s1 from the document and keep all the rest
Sed – n ‘1, 5 p; 5q’ hello.txt	Look at lines 1 through 5
sed -n ‘5p; 5q’ hello.txt	Look at line 5
paste file1 file2	Combine the contents of two files or columns
paste -d ‘+’ file1 file2	Combine the contents of two files or columns separated by a “+”
sort file1 file2	Sort the contents of two files
comm -1 file1 file2	Compare the contents of two files (remove contents contained in ‘file1’)
comm -2 file1 file2	Compare the contents of two files (excluding ‘file2’)
comm -3 file1 file2	Compare the contents of two files (excluding the common parts of both files)

Pack and unpack

Common commands	role
zip xxx.zip file	Zip to a ZIP package
zip -r xxx.zip file1 file2 dir1	Compress multiple files + directories into ZIP packages
unzip xxx.zip	Unpack the zip package
tar -cvf xxx.tar file	Create an uncompressed tar package
tar -cvf xxx.tar file1 file2 dir1	Tar multiple files and directories
tar -tf xxx.tar	View the content of the tar package
tar -xvf xxx.tar	Unpack the tar packages
tar -xvf xxx.tar -C /dir	Decompress the tar package to a specified directory
tar -cvfj xxx.tar.bz2 dir	Create the BZ2 zip package
tar -jxvf xxx.tar.bz2	Decompress the BZ2 package
tar -cvfz xxx.tar.gz dir	Create a gzip package
tar -zxvf xxx.tar.gz	Decompress the gzip package
bunzip2 xxx.bz2	Decompress the BZ2 package
bzip2 filename	The compressed file
gunzip xxx.gz	Decompress the gzip package
gzip filename	The compressed file
gzip -9 filename	Maximum compression

RPM package management command

Common commands	role
rpm -qa	Check the installed RPM packages
rpm -q pkg_name	Example Query an RPM package
rpm -q –whatprovides xxx	Shows which package XXX functionality is provided by
rpm -q –whatrequires xxx	Shows which package the XXX function is dependent on
rpm -q –changelog xxx	Displays change records for XXX package
rpm -qi pkg_name	View the details of a package
rpm -qd pkg_name	Query the documentation provided by a package
rpm -qc pkg_name	Check the configuration file provided by the installed RPM package
rpm -ql pkg_name	See what files a package has installed
rpm -qf filename	Check which package a file belongs to
rpm -qR pkg_name	Query package dependencies
rpm -ivh xxx.rpm	Install the RPM package
rpm -ivh –test xxx.rpm	Test the installation of RPM packages
rpm -ivh –nodeps xxx.rpm	Ignore dependencies when installing RPM packages
rpm -e xxx	Uninstall package
rpm -Fvh pkg_name	Upgrade RPM packages that have been installed
rpm -Uvh pkg_name	Upgrade RPM packages (if not installed)
rpm -V pkg_name	RPM package details verification

YUM package management command

Common commands	role
yum repolist enabled	Displays available source repositories
yum search pkg_name	Searching for software packages
yum install pkg_name	Download and install the software package
yum install –downloadonly pkg_name	Only under load can not be installed
yum list	Displays all packages
yum list installed	View the current system installation package
yum list updates	View the list of packages that can be updated
yum check-update	View upgradable software packages
yum update	Update all software packages
yum update pkg_name	Upgrading a specified software package
yum deplist pkg_name	Lists package dependencies
yum remove pkg_name	Deleting a Software Package
yum clean all	Clear the cache
yum clean packages	Clear the cached software package
yum clean headers	Clear cached headers

DPKG package management command

Common commands	role
dpkg -c xxx.deb	Lists the contents of deb packages
dpkg -i xxx.deb	Install/update deb packages
dpkg -r pkg_name	Remove the deb package
dpkg -P pkg_name	Remove deb package (without retaining configuration)
dpkg -l	Check the deb package installed in the system
dpkg -l pkg_name	Displays general information about the package
dpkg -L pkg_name	View the deb package installation file
dpkg -s pkg_name	View package details
DPKG — unpack XXX. Deb	Unpack the contents of the DEB package

APT Software Tools

Common commands	role
apt-cache search pkg_name	Search package
apt-cache show pkg_name	Get overview information for packages
apt-get install pkg_name	Install or upgrade software packages
apt-get purge pkg_name	Uninstalling software (including configuration)
apt-get remove pkg_name	Uninstalling software (excluding configuration)
apt-get update	Update the package index
apt-get upgrade	Update the installed software package
apt-get clean	Clear the cache