Hardcore! A summary of high-frequency Linux commands, it is recommended to collect~

Preface

some useful and efficient online tools and websites in daily work, study, development, writing, making videos, etc., and I also added my own browser favorites The bookmark offline files are exported to you .

The feedback from many small partners in the background is pretty good, saying that after the bookmarks are imported, many tools are really easy to use, which saves a lot of time in finding resources and organizing.

I continue to share today. Recently, I spent a lot of time to sort out some of the Linux system commands that are commonly used in the usual development process, and form a common high-frequency Linux quick reference memo. With it, are you afraid that you can't remember the common operations and commands of the Linux operating system?

Let's serve directly next.

Note: This article GitHub https://github.com/rd2coding/Road2Coding has been included, and there are my own 6 programming directions (posts) self-study routes + knowledge points combing , , resume 160d3e02d8f823, hardcore pdf notes , and my programmer life .

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Shutdown/restart/logout

Common commands	effect
shutdown -h now	Shut down now
shutdown -h 10	Shut down after 10 minutes
shutdown -h 11:00	11:00 shutdown
shutdown -h +10	Shut down at scheduled time (10 minutes later)
shutdown -c	Cancel the specified time to shut down
shutdown -r now	Reboot
shutdown -r 10	Restart in 10 minutes
shutdown -r 11:00	Restart regularly
reboot	Reboot
init 6	Reboot
init 0	Shut down immediately
telinit 0	Shut down
poweroff	Shut down immediately
halt	Shut down
sync	Synchronize buff data to disk
logout	Log out of the login shell

Note: What is the difference between shutdown, poweroff, halt, and init 0 for the same shutdown? If you are interested, you can find out for yourself, they are different.

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System information and performance view

The command here is actually used a lot, because once the system or background service has problems, we often have to log on to view it, including a lot of system information, such as: system version, kernel version, processor architecture, computer name, environment Variables, user conditions, load conditions, memory usage, disk information, processes, network connections...

Common commands	effect
uname -a	View kernel/OS/CPU information
uname -r	View kernel version
uname -m	View processor architecture
arch	View processor architecture
hostname	View computer name
who	Display the users currently logged in to the system
who am i	Display the user name when logging in
whoami	Display current user name
cat /proc/version	View linux version information
cat /proc/cpuinfo	View CPU information
cat /proc/interrupts	View interrupt
cat /proc/loadavg	View system load
uptime	View system running time, number of users, load
env	View system environment variables
lsusb -tv	View system USB device information
lspci -tv	View system PCI device information
lsmod	View the loaded system modules
grep MemTotal /proc/meminfo	View the total amount of memory
grep MemFree /proc/meminfo	View the amount of free memory
free -m	View memory usage and swap area usage
date	Display system date and time
cal 2021	Show 2021 calendar
top	Dynamic display of cpu/memory/process, etc.
vmstat 1 20	The system status is collected every 1 second, 20 times
iostat	View io read/write/cpu usage
sar -u 1 10	Query cpu usage (once every 1 second, 10 times in total)
sar -d 1 10	Query disk performance

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Disks and partitions

These are some commonly used commands that are closely related to daily use. In Windows, we can view them on the graphical interface with a click of the mouse. However, in Linux, we should be proficient in using commands to view, such as: viewing various partition information, Disk usage, file and directory size, various mounting and unmounting...

Common commands	effect
fdisk -l	View all disk partitions
swapon -s	View all swap partitions
df -h	View disk usage and mount point
df -hl	Check the remaining space on the disk
du -sh /dir	View the specified directory size
`du -sk *	sort -rn`	Display file and directory sizes in order from high to low
mount /dev/hda2 /mnt/hda2	Mount hda2 disk
mount -t ntfs /dev/sdc1 /mnt/usbhd1	Specify the file system type to mount (such as ntfs)
mount -o loop xxx.iso /mnt/cdrom	Mount the iso file
mount /dev/sda1 /mnt/usbdisk	Mount usb disk/flash device
umount -v /dev/sda1	Uninstall by device name
umount -v /mnt/mymnt	Unmount via mount point
fuser -km /mnt/hda1	Force uninstall (use with caution)

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Users and user groups

User groups and users themselves are also a very important concept in the Linux system. This part of the commands is mainly about: user CRUD, user group CURD, and then also include checking users, switching users, changing passwords, checking user login logs...

Common commands	effect
useradd codesheep	Create user
userdel -r codesheep	delete users
usermod -g group_name user_name	Modify user's group
usermod -aG group_name user_name	Add user to 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	Create user group
groupdel group_name	Delete user group
groupmod -n new_name old_name	Rename user group
su - user_name	Completely switch to a user environment
passwd	Change password
passwd codesheep	Modify a user's password
w	View active users
id codesheep	View specified user information
last	View user login logs
crontab -l	View the scheduled tasks of the current user
cut -d: -f1 /etc/passwd	View all users of the system
cut -d: -f1 /etc/group	View all groups in the system

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Network and process management

As a back-end development, these commands are usually used with high probability, such as: view network, view connection, view port service, configure network card/firewall/routing table/DNS, view and filter process, collect system status, and Some system performance monitoring and troubleshooting commands... etc. These commands are very useful when the back-end development connects to the company's server to troubleshoot problems, and they are used frequently.

Common commands	effect
ifconfig	View network interface properties
ifconfig eth0	View the configuration of a network card
route -n	View routing table
netstat -lntp	View all listening ports
netstat -antp	View all established connections
netstat -lutp	View TCP/UDP status information
ifup eth0	Enable eth0 network device
ifdown eth0	Disable eth0 network device
iptables -L	View iptables rules
ifconfig eth0 192.168.1.1 netmask 255.255.255.0	Configure ip address
dhclient eth0	Enable eth0 in dhcp mode
route add -net 0/0 gw Gateway_IP	Configure the default gateway
route add -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.1.1	Configure a static route to reach the network '192.168.0.0/16'
route del 0/0 gw Gateway_IP	Delete static route
hostname	View hostname
host www.codesheep.cn	Resolve hostname
nslookup www.codesheep.cn	Query DNS records to check whether the domain name resolution is normal
ps -ef	View all processes
`ps -ef	grep codesheep`	Filter out the processes you need
kill -s name	kill the process with the specified name
kill -s pid	kill the process of the specified pid
top	Real-time display of process status
vmstat 1 20	The system status is collected every 1 second, 20 times
iostat	View io read/write/cpu usage
sar -u 1 10	Query cpu usage (once every 1 second, 10 times in total)
sar -d 1 10	Query disk performance

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Common system service commands

Such commands are usually exposed to many, such as when we install and deploy a variety of basic programming environments and services, such as JDK, MySQL database, redis cache, nginx server...

Common commands	effect
chkconfig --list	List system services
service <service name> status	View a service
service <service name> start	Start a service
service <service name> stop	Terminate a service
service <service name> restart	Restart a service
systemctl status <service name>	View a service
systemctl start <service name>	Start a service
systemctl stop <service name>	Terminate a service
systemctl restart <service name>	Restart a service
systemctl enable <service name>	Turn on self-start
systemctl disable <service name>	Turn off self-start

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File and directory operations

These commands are all the basic operations used by the Linux system, and they are also some of the most frequently used commands, such as file operations, directory operations, and paths. For example: various high-frequency operations on files and directories, creating, viewing, searching, deleting, renaming, copying, soft linking, fast positioning and searching... etc. They are all high-frequency practical commands.

Common commands	effect
cd <directory name>	Enter a directory
cd ..	Back to the parent directory
cd ../..	Back to the two-level directory
cd	Enter personal home directory
cd -	Back to the directory where the previous step was located
pwd	Show current path
ls	View file directory list
ls -F	View the contents of the directory (show whether it is a file or a directory)
ls -l	View the detailed list of files and directories
ls -a	View hidden files
ls -lh	Show permissions
ls -lSr	more	View files/directories by size
tree	View the tree structure of files and directories
mkdir <directory name>	Create a directory
mkdir dir1 dir2	Create two directories at the same time
mkdir -p /tmp/dir1/dir2	Create directory tree
rm -f file1	Delete file'file1'
rmdir dir1	Delete the'dir1' directory
rm -rf dir1	Delete the'dir1' directory and its contents
rm -rf dir1 dir2	Delete two directories and their contents at the same time
mv old_dir new_dir	Rename/move directory
cp file1 file2	Copy files
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 a soft link to the file/directory
ln file1 lnk1	Create a physical link to the file/directory
find / -name file1	Search for files/directories starting from the following directory
find / -user user1	Search files/directories of user user1
find /dir -name *.bin	Search for files with a .bin suffix in the directory /dir
locate keywords	Quickly locate files
locate *.mp4	Looking for files ending in .mp4
whereis halt	Display the path of a binary file/executable file
which halt	Find the binary file in the system directory
chmod ugo+rwx dir1	Set the read (r) write (w) execution (x) permissions of the owner (u), group (g) and others (o) of the directory
chmod go-rwx dir1	Remove group (g) and others (o) permissions to read and write to the directory
chown user1 file1	Change the owner attribute of the file
chown -R user1 dir1	Change the owner attribute of the directory
chgrp group1 file1	Change file group
chown user1:group1 file1	Change owner and group of file

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File viewing and processing

This part of the command is mainly related to file processing or text processing. For example, as a programmer, the code source file is the most manipulated. Various fancy viewing, comparison, addition, deletion, replacement, merging... etc. Wait for a series of quick operations.

Common commands	effect
cat file1	View file content
cat -n file1	View the content and mark the number of lines
cat xxx.txt	awk 'NR%2==1'	View all odd lines in the file
tac file1	Look back at the contents of the file from the last line
more file1	View the contents of a long file
less file1	Similar to the more command, but allows reverse operation
head -2 file1	View the first two lines of the file
tail -2 file1	View 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	Find the keyword codesheep in the file hello.txt
grep ^sheep hello.txt	Find the content starting with sheep in the file hello.txt
grep [0-9] hello.txt	Select all lines containing numbers in the hello.txt file
sed 's/s1/s2/g' hello.txt	Replace s1 in the hello.txt file with s2
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 rows that only contain the keyword "s1"
sed -e 's/ *$//' hello.txt	Delete the last blank character in each line
sed -e 's/s1//g' hello.txt	Delete only vocabulary s1 from the document and keep all remaining
sed -n '1,5p;5q' hello.txt	View the content from the first row to the fifth row
sed -n '5p;5q' hello.txt	View line 5
paste file1 file2	Combine the contents of two files or two columns
paste -d '+' file1 file2	Combine the contents of two files or two columns, separated by "+" in the middle
sort file1 file2	Sort the contents of two files
sort file1 file2	uniq	Take out the union (only keep one copy of duplicate rows)
sort file1 file2	uniq -u	Delete the intersection and leave other rows
sort file1 file2	uniq -d	Take intersection
comm -1 file1 file2	Compare the contents of two files (remove the contents of'file1')
comm -2 file1 file2	Compare the contents of two files (remove the contents of'file2')
comm -3 file1 file2	Compare the contents of two files (remove the common part of the two files)

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Pack and unzip

This part of the content is mainly about the packaging, compression and decompression of files or directories. It involves several compressed package formats and files. This part of the command is usually used very, very frequently.

Common commands	effect
zip xxx.zip file	Compressed to zip package
zip -r xxx.zip file1 file2 dir1	Compress multiple files + directories into a zip package
unzip xxx.zip	Unzip the zip package
tar -cvf xxx.tar file	Create a non-compressed tar package
tar -cvf xxx.tar file1 file2 dir1	Tar package multiple files + directories
tar -tf xxx.tar	View the contents of the tar package
tar -xvf xxx.tar	Unzip the tar package
tar -xvf xxx.tar -C /dir	Unzip the tar package to the specified directory
tar -cvfj xxx.tar.bz2 dir	Create bz2 compressed package
tar -jxvf xxx.tar.bz2	Unzip the bz2 compressed package
tar -cvfz xxx.tar.gz dir	Create gzip archive
tar -zxvf xxx.tar.gz	Unzip the gzip compressed package
bunzip2 xxx.bz2	Unzip the bz2 compressed package
bzip2 filename	Compressed file
gunzip xxx.gz	Unzip the gzip compressed package
gzip filename	Compressed file
gzip -9 filename	Maximum compression

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Then there are some common package manager commands. First of all, everyone should know what a package manager is.

Let's put it this way, if there is no such thing as a package manager, it is probably only the software installation on the Linux system. I am afraid that many users will be dissuaded, because a lot of software dependence processing will make people crazy. So in simple terms, we can understand the package manager as a component used to provide support for software installation, uninstallation, upgrade, and query on Linux systems, so for users, it is generally a set of tool commands.

We usually use the most widely used, for example, Red Hat’s package structure RPM package manager, which is used in systems such as RedHat, CentOS, etc. The typical commands are rpm commands, yum commands; then there are DPKG package managers, such as Debain, Ubuntu and other systems. Both are used, typical commands such as dpkg command and apt software tool.

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rpm package management commands

Common commands	effect
rpm -qa	View installed rpm packages
rpm -q pkg_name	Query a rpm package
rpm -q --whatprovides xxx	Show which package provides the xxx function
rpm -q --whatrequires xxx	Show which package depends on the xxx function
rpm -q --changelog xxx	Display the change record of 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	View the configuration file provided by the installed rpm package
rpm -ql pkg_name	View which files are installed by a package
rpm -qf filename	See 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 install rpm package
rpm -ivh --nodeps xxx.rpm	Ignore dependencies when installing rpm packages
rpm -e xxx	Uninstall package
rpm -Fvh pkg_name	Upgrade to determine the installed rpm package
rpm -Uvh pkg_name	Upgrade rpm package (if not installed, it will be installed)
rpm -V pkg_name	RPM package detailed information verification

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yum package management commands

Common commands	effect
yum repolist enabled	Show available source repositories
yum search pkg_name	Search package
yum install pkg_name	Download and install the software package
yum install --downloadonly pkg_name	Only download but not install
yum list	Show all packages
yum list installed	View the installed packages of the current system
yum list updates	View the list of packages that can be updated
yum check-update	View upgradeable packages
yum update	Update all packages
yum update pkg_name	Upgrade the specified software package
yum deplist pkg_name	List package dependencies
yum remove pkg_name	Remove package
yum clean all	clear cache
yum clean packages	Clear cached packages
yum clean headers	Clear the cached header

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dpkg package management commands

Common commands	effect
dpkg -c xxx.deb	List the contents of the deb package
dpkg -i xxx.deb	Install/update deb package
dpkg -r pkg_name	Remove deb package
dpkg -P pkg_name	Remove the deb package (do not keep the configuration)
dpkg -l	View the installed deb package in the system
dpkg -l pkg_name	Show general information about the package
dpkg -L pkg_name	View the files installed by the deb package
dpkg -s pkg_name	View package details
dpkg –unpack xxx.deb	Unpack the contents of the deb package

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apt software tools

Common commands	effect
apt-cache search pkg_name	Search package
apt-cache show pkg_name	Get overview information of the package
apt-get install pkg_name	Install/upgrade packages
apt-get purge pkg_name	Uninstall the software (including configuration)
apt-get remove pkg_name	Uninstall the software (not including configuration)
apt-get update	Update package index information
apt-get upgrade	Update installed packages
apt-get clean	Clear cache

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Offline documents

In addition to the above content, this review also brought out those high-frequency and practical Linux commands, and made two forms of offline documents, which are PDF format and high-definition picture format. PDF is convenient for computer viewing, and high-definition pictures are convenient. Use your mobile phone to view it, so you can take out all the effort you need to take a look at it on your mobile phone.

The PDF document is roughly like this:

The high-definition pictures are almost like this, there are a dozen of them, and they contain hundreds of commands:

The document GitHub https://github.com/rd2coding/Road2Coding has been included.

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postscript

In addition, I have recently spent a lot of effort to organize the programming learning resources for my own use.

They are all pure liver products, the catalog is as follows.

The content GitHub https://github.com/rd2coding/Road2Coding already included, there is also my finishing self-line six directions + programming knowledge large comb , my resume , interview test sites , several hardcore pdf notes , and My Programmer's Life , welcome star.

It is not easy to organize, welcome support, see you next time!