Linux Common Commands Summary

Online Enquiry and Help commands (2)

Command	Function description
Mans	View command Help, Dictionary of commands, more complex and info.
Help	See Help for Linux built-in commands.

/tr> Td>dirname

file and Directory operations commands (18)

Command	function description
ls	lists the contents of the directory and their content property information
cd	switch from the current working directory to the specified working directory
cp	copy files or directories
find	for finding directories and items Recorded file
mkdir	Create a directory
mv	Move or rename a file
pwd	Displays the absolute path of the current working directory
rename	rename file
rm	Delete one or more Files or directories
rmdir	Delete empty directory
Touch	Create a new empty file, change the time attribute of an existing file
Tree	to display the contents of a directory in a TreeView
basename	Show file name or directory name
to display a file or directory path
chattr	Change the extended properties of a file
lsattr	View extended Properties for a file
file	displays the types of files
md5sum	Calculating and verifying the MD5 value of a file

view file and content processing commands (21)

Command	Function description
Cat	Connect multiple files and print to the screen output or redirect to the specified file
Tac	TAC is the reverse spelling of cat, displaying file contents in reverse
More	Page display of file contents
Less	Pagination shows the contents of a file, the opposite usage of the more command
Head	Displays the header of the file class capacity
Tail	Display the end of a file's contents
Cut	Splits each line of a file by the specified delimiter and outputs it.
Split	Split files into different small fragments
Paste	Merge file contents by row
Sort	Sort the text content of a file
Uniq	Remove Duplicate rows
Wc	The number of rows, words, or bytes of the statistics file.
Iconv	encoding format for converted Files
Dos2unix	Convert DOS format files to UNIX format
Diff	Compare file differences
Vimdiff	Command line visual file Comparison tool
Rev	Reverse Output file contents
Grep/egrep	Filter strings, one of the Three Musketeers
Join	Merge by same field of two files
Tr	Replace or delete characters
Vi/vim	Command line Text Editor

File compression and Decompression commands (4)

Command	Function description
Unzip	Unzip the file
Gzip	Gzip Compression Tool
Tar	Packaging compression
Zip	Compression tools

Information display commands (11)

Command	Function description
Uname	Commands to display information about the operating system
Hostname	Displays or sets the host name of the current system
Dmesg	Display boot information for diagnosing system failures
Uptime	Display system run time and load
Stat	Show the status of a file or file system
Du	Calculate disk space usage
Df	Report the use of file system disk space
Top	Real-time display of system resource usage
Free	viewing system memory
Date	Display and set system time
Aa.	View time information such as calendars

Search Files Command (4)

Command	Function description
which	Find binary commands, search by environment variable path path
Find	To find a file or directory from a disk traversal
Whereis	Find binary commands, search by environment variable path path
Locate	Find commands from a database

User Management commands (10)

Command	Function description
Useradd	Add user
Usermod	Modifying user attributes that already exist on the system
Userdel	Delete User
Groupadd	To add a user group
passwd	Modify User Password
Chage	Modify User Password Expiration
Id	View user's Uid,gid and attribution user groups
Su	Switch User identities
Visudo	Exclusive commands for editing/etc/sudoers files
Sudo	Perform the commands previously allowed in the Suders file as another user (the default root user).

Basic Network Operations Commands (11)

Command	Function description
Telnet	Remote Login using Telnet protocol
Ssh	Remote login using SSH encryption protocol
Scp	Used to copy files between different hosts
Wget	Command line download file
Ping	Test the network connectivity between hosts
Route	Displaying and setting the routing table for a Linux system
Ifconfig	To view, configure, start, or disable a network interface command
Ifup	Start the network card
Ifdown	Turn off the NIC
Netstat	View network Status
Ss	View network Status

Deep Network Operations Command (9)

Command	Function description
Lsof	Enumerate files that have been opened in the system
Mail	Send and receive files
Mutt	Mail Management commands
Nslookup	Interactive query for Internet DNS server commands
Dig	To view the DNS resolution process
Host	To view DNS commands
Nmap	Network Scan Command
Traceroute	Track data transfer routing status
Tcpdump	Command-line Grab Bag tool

commands for disks and file Systems (16)

Command	Function description
Mount	Mount File System
Umount	Uninstalling the file system
Fack	Check and repair the Linux file system
Dd	converting copied files
Dumpe2fs	Export File System Information
Dump	File System Backup Tool
Fdisk	Disk partitioning command, for 2TB or less disk partitions
Parted	Disk partitioning command, no disk size limit, commonly used for 2TB or less disk partitions
Mkfs	Format and create a Linux file system
Partprobe	Update the disk partition table information for the kernel
E2fsck	Check the EXT2/EXT3/EXT4 type file system
Mkswap	Creating a Linux Swap partition
Swapon	Enable swap partition
Awapoff	Close Swap partition
Sync	To write data from a memory buffer to disk
Resize2fs	Resizing the Ext2/ext3/ext4 file system

System permissions and user authorization related commands (4)

Command	Function description
chmod	Change file or directory permissions
Chown	Change the owner and owner of a file or directory
Chgrp	Change file User Group
Umask	Display or set a permission mask

Commands to view system user login information (7)

Command	Function description
WhoAmI	Displays the currently valid user name, equivalent to executing the id-un command
W.H.O.	Displays user information for the current login system
W	Displays a list of users who have logged in to the system and displays the instructions that the user is executing
Last	Show users logged in to the system
Lastlog	Displays the most recent login information for all users in the system
Users	Displays a list of all users of the current login system
Finger	Find and display user information

built-in commands and other

Command	Function description
Echo	Prints the variable, or outputs the specified string directly
Printf	Format the results to standard output
Rpm	Manage RPM Package Commands
Yum	Commands for automating the easy management of RPM packages
Watch	Executes the given command periodically and displays the output of the command in full-screen mode
Alias	Set System aliases
Unalias	To cancel a system alias
Date	View or set the system time
Clear	Clear Screen
History	View the History of command execution
Eject	Eject Optical Drive
Time	Calculate Command Execution time
nc	Powerful networking tools
Xargs	Convert standard input to command line arguments
Exec	command to invoke and execute instructions
Export	setting or displaying environment variables
unset	Delete a variable or function
Type	Used to determine if another command is a built-in command
Bc	Calculator

System Management and performance monitoring commands (9)

Command	Function description
Chkconfig	Managing Linux System Boot entry
Vmstat	Virtual Memory Statistics
Mpstat	Displays status statistics for each available CPU
Iostat	Statistical system IO
Sar	Full access to system performance data such as CPU, run queue, disk I/O, paging (swap), memory, CPU interrupt, and network
IPCs	Used to report the status of interprocess communication facilities in Linux, and the information displayed includes information about Message Queuing, shared memory, and semaphores.
Ipcrm	Used to delete one or more message queues, semaphore sets, or shared memory identities
Strace	For diagnosing and debugging Linux user space trackers. We use it to monitor the interaction between the user control process and the kernel, such as system calls, signal transmission, etc.
Itrace	The command tracks the library function call of the process, which shows that the library function is called

Commands for shutting down, restarting, logging off, and viewing system information (6)

Command	Function description
Shutdown	Shutdown
Halt	Shutdown
Poweroff	Power off
Logout	Exit the shell that is currently logged in
Exit	Exit the shell that is currently logged in
Ctrl+d	Exit the fast-build of the currently logged-in shell

Process Management Related commands (15)

Command	Function description
Fg	The command in the background is moved to the foreground to continue execution
Jobs	See how many commands are currently executing in the background
Kill	Terminating a process
Killall	Terminating a process with a process name
Pkill	Terminating a process with a process name
Crontab	Timed Task commands
Ps	To display a snapshot of a process
Pstree	Tree Display Process
Nice/renice	Prioritize program runs
Nohup	command to ignore pending signal run instructions
Pgrep	Find a process for matching criteria
RunLevel	Find the current operating level of the system
Init	Switching the Run level
Service	Start, stop, restart, and shut down system services, and also display the current status of all system services
Bg	A command paused in the background to continue execution (performed in the background)

Linux Common Commands Summary