Command |
Function description |
Online Enquiry and Help commands (2) |
Mans |
View command Help, Dictionary of commands, more complex and info, but not commonly used. |
Help |
See Help for Linux built-in commands, such as CD commands. |
File and Directory operations commands (18) |
Ls |
Full spelling list, which is a listing of the contents of a directory and its content property information. |
Cd |
Full spelling change directory, which switches from the current working directory to the specified working directory. |
Cp |
Full copy, with the ability to copy files or directories. |
Find |
Find the meaning, used to find the directory and the file under the directory. |
Mkdir |
Full make directories, its function is to create a directory. |
Mv |
Full move, the function is to move or rename the file. |
Pwd |
Full print working directory with the ability to display an absolute path to the current working directory. |
Rename |
Used to rename a file. |
Rm |
Remove all, its function is to delete one or more files or directories. |
RmDir |
Completely remove empty directories, the function is to delete the blank directory. |
Touch |
Creates a new empty file, changing the timestamp property of an existing file. |
Tree |
The function is to display the contents of the directory in a tree-shaped structure. |
BaseName |
Displays the file name or directory name. |
DirName |
Displays the file or directory path. |
Chattr |
Changes the extended properties of the file. |
Lsattr |
View file extension properties. |
File |
Displays the type of file. |
Md5sum |
Calculates and verifies the MD5 value of the file. |
View file and Content processing commands (21) |
Cat |
Full spell concatenate, which is used to connect multiple files and print to the screen output or redirect to a specified file. |
Tac |
The TAC is the inverse spelling of cat, so the function of the command is to display the file contents in reverse. |
More |
Page displays the contents of the file. |
Less |
Pagination Displays the contents of the file, the opposite usage of the more command. |
Head |
Displays the header of the file contents. |
Tail |
Displays the tail of the file content. |
Cut |
Splits each line of a file by the specified delimiter and outputs it. |
Split |
Split the file into different small fragments. |
Paste |
Merges file contents by row. |
Sort |
Sorts the text content of the file. |
Uniq |
Remove duplicate rows. Oldboy |
Wc |
The number of rows, words, or bytes of the statistics file. |
Iconv |
The encoding format of the converted file. |
Dos2unix |
Convert DOS format files to UNIX format. |
Diff |
Full spelling difference, comparing file differences, often used in text files. |
Vimdiff |
Command line Visual file Comparison tool, commonly used in text files. |
Rev |
Reverse output file contents. |
Grep/egrep |
Filter strings, three musketeers old three. |
Join |
Merge by the same field as two files. |
Tr |
Replace or delete characters. |
Vi/vim |
command line text editor. |
File compression and Decompression commands (4) |
Tar |
Package compression. Oldboy |
Unzip |
Unzip the file. |
Gzip |
Gzip compression tool. |
Zip |
Compression tool. |
Information display commands (11) |
Uname |
A command that displays information about the operating system. |
Hostname |
Displays or sets the host name of the current system. |
Dmesg |
Displays the boot information for diagnosing system failures. |
Uptime |
Displays system run time and load. |
Stat |
Displays the status of the file or file system. |
Du |
Calculate disk space usage. |
Df |
Reports on the use of file system disk space. |
Top |
Real-time display of system resource usage. |
Free |
View system memory. |
Date |
Displays and sets the system time. |
Cal |
View time information such as calendars. |
Search Files Command (4) |
which |
Find the binary command, which is found by the environment variable path PATH. |
Find |
Find files or directories from disk traversal. |
Whereis |
Find the binary command, which is found by the environment variable path PATH. |
Locate |
From the database (/var/lib/mlocate/mlocate.db) Lookup command, use UpdateDB to update the library. |
User Management commands (10) |
Useradd |
Add Users. |
Usermod |
Modifies a user attribute that already exists on the system. |
Userdel |
Delete the user. |
Groupadd |
Add a user group. |
passwd |
Modify the user password. |
Chage |
Modify the user password validity period. |
Id |
View the user's Uid,gid and attribution user groups. |
Su |
Switch user identities. |
Visudo |
Edit the exclusive commands for the/etc/sudoers file. |
Sudo |
Perform the commands previously allowed in the Sudoers file as another user (the default root user). |
Basic Network Operations Commands (11) |
Telnet |
Log on remotely using the Telnet protocol. |
Ssh |
Telnet using SSH encryption protocol. |
Scp |
Full secure copy for copying files between different hosts. |
Wget |
command line to download the file. |
Ping |
Test the connectivity of the network between hosts. |
Route |
Displays and sets the routing table for the Linux system. |
Ifconfig |
View, configure, enable, or disable a command for a network interface. |
Ifup |
Start the network card. |
Ifdown |
Turn off the network card. |
Netstat |
View network status. |
Ss |
View network status. |
Deep Network Operations Command (9) |
Nmap |
The Network Scan command. |
Lsof |
Full Name list open files, which is the file that is already opened in the system. |
Mail |
Send and receive messages. |
Mutt |
Mail management commands. |
Nslookup |
Interactively query the commands of the Internet DNS server. |
Dig |
Find the DNS resolution process. |
Host |
A command that queries DNS. |
Traceroute |
Track data transmission routing status. |
Tcpdump |
Command-line Grab kit. |
Commands for disks and file systems (16) |
Mount |
Mount the file system. |
Umount |
Unmount the file system. |
Fsck |
Check and repair the Linux file system. |
Dd |
Convert or copy files. |
Dumpe2fs |
Export EXT2/EXT3/EXT4 file system information. |
Dump |
EXT2/3/4 File System Backup tool. |
Fdisk |
The disk partitioning command, which is suitable for disk partitions below 2TB. |
Parted |
The disk partitioning command, which has no disk size limit, is commonly used for disk partitions below 2TB. |
Mkfs |
Format to create a Linux file system. |
Partprobe |
Update the kernel's hard disk partition table information. |
E2fsck |
Check the EXT2/EXT3/EXT4 type file system. |
Mkswap |
Create a Linux swap partition. |
Swapon |
Enable the swap partition. |
Swapoff |
Close the swap partition. |
Sync |
Writes the data in the memory buffer to disk. |
Resize2fs |
Adjusts the size of the Ext2/ext3/ext4 file system. |
System permissions and user authorization related commands (4) |
chmod |
Change file or directory permissions. |
Chown |
Change the owner and owner group of a file or directory. |
Chgrp |
Change the file user group. |
Umask |
Displays or sets the permission mask. |
Commands to view system user login information (7) |
WhoAmI |
Displays the currently valid user name, which is equivalent to executing the id-un command. |
W.H.O. |
Displays user information for the currently logged on system. |
W |
Displays a list of users who have logged in to the system and displays the instructions that the user is executing. |
Last |
Displays the user who logged into the system. |
Lastlog |
Displays the last logon information for all users in the system. |
Users |
Displays the list of users for all users who are currently logged on to the system. |
Finger |
Find and display user information. |
Built-in commands and others (19) |
Echo |
Prints the variable, or outputs the specified string directly |
Printf |
The result is formatted to output to standard output. |
Rpm |
Commands for managing RPM packages. |
Yum |
Automate the simple management of RPM package commands. |
Watch |
Executes the given command periodically and displays the output of the command in full-screen mode. |
Alias |
Sets the system alias. |
Unalias |
Cancels the system alias. |
Date |
View or set the system time. |
Clear |
Clear the screen, for short, clear screen. |
History |
View the history of the command execution. |
Eject |
Eject the optical drive. |
Time |
Calculates the command execution time. |
nc |
Powerful Network Tools. |
Xargs |
Converts the standard input to a command-line parameter. |
Exec |
The command that invokes and executes the instruction. |
Export |
Sets or displays environment variables. |
unset |
Delete a variable or function. |
Type |
Used to determine if another command is a built-in command. |
Bc |
Command Line Scientific calculator |
System Management and performance monitoring commands (9) |
Chkconfig |
Manage Linux system boot entry. |
Vmstat |
Virtual memory statistics. |
Mpstat |
Displays status statistics for each available CPU. |
Iostat |
Statistical system IO. |
Sar |
Gain full access to system performance data such as CPU, run queue, disk I/O, paging (swap area), memory, CPU interrupt, and network. |
IPCs |
Used to report the status of interprocess communication facilities in Linux, including information about message lists, 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 user space processes and kernel interactions, such as system invocation, signal delivery, process state changes, and so on. |
Ltrace |
The command tracks the library function call of the process and it shows which library function is called. |
Commands to shut down/restart/logoff and view system Information (6) |
Shutdown |
Shutdown. |
Halt |
Shutdown. |
Poweroff |
Power off. |
Logout |
Exits the currently logged-on shell. |
Exit |
Exits the currently logged-on shell. |
Ctrl+d |
Exits the shortcut key for the currently logged-on shell. |
Process Management related commands (15) |
Bg |
A command that pauses in the background changes to continue execution (performed in the background). |
Fg |
The commands in the background are moved to the foreground to continue running. |
Jobs |
See how many commands are currently running in the background. |
Kill |
Terminates the process. |
Killall |
Terminates the process through the process name. |
Pkill |
Terminates the process through the process name. |
Crontab |
Timed Task command. |
Ps |
Displays a snapshot of the process. |
Pstree |
The tree displays the process. |
Nice/renice |
Adjusts the priority of the program to run. |
Nohup |
Ignores the pending signal to run the specified command. |
Pgrep |
Finds a process that matches a condition. |
RunLevel |
View the current operating level of the system. |
Init |
Toggles the run level. |
Service |
Start, stop, restart, and shut down system services, and also display the current status of all system services. |