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How to Manage Your Alibaba Cloud Linux Server from the Command Line Interface (CLI)

In this guide, we will show you how to manage your Alibaba Cloud Linux ECS instance from the Command Line Interface (CLI).

By Francis Ndungu, Alibaba Cloud Tech Share Author. Tech Share is Alibaba Cloud's incentive program to encourage the sharing of technical knowledge and best practices within the cloud community.

Alibaba Cloud offers flexible Elastic Compute Service (ECS) products for running powerful Virtual Private Servers (VPS). With their simple and transparent pricing starting from $4.50/month, you can setup a remote server to cater for all your cloud hosting needs.

You can deploy an Alibaba Cloud ECS instance in a few minutes right from their friendly console and scale resources up or down depending on your cloud computing needs.

Alibaba Cloud infrastructure runs with the latest Intel CPU's, fast RAM, accelerated SSD, and unrivalled security bundled with intelligent DDoS protection. You can choose from their wide-range of Operating System images for accelerated application deployment.

Since most of the world's powerful servers run on Linux, we will focus on managing your Alibaba Cloud Linux ECS instance from the Command Line Interface (CLI).This guide works for all Linux distributions and covers most commands for managing your Alibaba Cloud VPS instance.

Prerequisites

  • A valid Alibaba Cloud account. If you don't have one, try Alibaba Cloud today and get $300 worth in Free Trial.
  • An ECS instance running any Linux distribution (e.g. Ubuntu, Centos, Debian)
  • An SSH username and password for the ECS instance.
  • For the sake of simplicity we will be using a hypothetical user 'james'.

1: Linux whoami Command

To start exploring your Alibaba Cloud ECS VPS, you need to SSH to your server. You will need a command line tool like PuTTY (Windows) or terminal window in Linux or Mac. Also, get the public IP address, username and password associated with your ECS instance.

The first command that you need to know about is whoami. This command lists the username of the currently logged in user in a SSH session.

$ whoami

Output

james

You can also issue the id –un command to get the same output.

2: Linux pwd Command

The Linux pwd (Print Working Directory) command displays the full path name of the working directory. Please note in Linux, commands and filenames are case sensitive.

Therefore use the correct case otherwise you will get an error.

$ pwd

Output

 /home/james

3: Linux cd Command

In Linux, the cd command stands for Change Directory. It is one of the most useful commands because it allows users to move around or change focus from one directory to another.

For instance if the home directory for user 'james' contains a test directory, you can navigate to it using the command below:

$ cd test

Output

$ james@server1:~/test$

If you want to move back one level, type two dots after the cd command as shown below:

$ cd ..

Output

$ james@server1:~$

To move to the root of your Linux server, type cd followed by a space and a forward slash:

$ cd /

Output

james@server1:/$

4: Linux ls Command

The ls command is used to list directory contents. The list includes all files, folders and symbolic links within the directory:

$ ls

Output

$mail  test

To display more information about the directory content, use the -l option as shown below:

$ ls –l

Output

drwx------ 3 james james 4096 Jul  1 11:49 mail
drwxrwxr-x 2 james james 4096 Jul 16 08:23 test

5: Linux mkdir Command

The mkdir command is used for creating directories on a Linux machine. Creating folders is a common task in Linux administration.

To create a directory named 'demo', use the command below:

$ mkdir demo

If we issue the ls -l command one more time, the demo directory should be listed on our home folder:

$ ls –l

Output

drwxrwxr-x 2 james james 4096 Jul 16 09:07 demo
drwx------ 3 james james 4096 Jul  1 11:49 mail
drwxrwxr-x 2 james james 4096 Jul 16 08:23 test

6: Linux touch Command

Just like the way we created a directory, we can create a file using the touch command. For instance, to create a file named text1.txt, the syntax should be as follows:

$ touch text1.txt

You always use run the ls -l command to confirm the presence of newly created files:

$ ls -l

Output

drwxrwxr-x 2 james james 4096 Jul 16 09:07 demo
drwx------ 3 james james 4096 Jul  1 11:49 mail
drwxrwxr-x 2 james james 4096 Jul 16 08:23 test
-rw-rw-r-- 1 james james    0 Jul 16 09:08 text1.txt

7: Linux rmdir Command

You can remove an empty directory in Linux by issuing a rmdir command. For instance, to remove the 'demo' folder that we created above, the command should be as follows:

$ rmdir demo

Please note: You cannot delete a directory if it is not empty using the rmdir command. You have to use the rm -r command as discussed below:

8: Linux rm Command

The rm command is used to remove objects including files, directories and symbolic links in Linux.

To remove the file you created above named 'text1.txt', use the command below:

$ rm text1.txt

To remove a directory together with its contents, issue the command below:

$ rm -r 

For instance, to remove the non-empty 'demo' folder, the command should be as follows:

$ rm -r demo

9: Linux cp Command

Sometimes, you may need to copy a file or a bunch of files in Linux. This can be done using the cp command. The basic syntax is shown below:

$ cp 

For instance, let's create a file named 'demo1.txt' and try to copy it.

$ touch demo1.txt

Once the file is created we can copy it over to 'demo2.txt' using the syntax below:

$ cp demo1.txt demo2.txt

We can confirm the presence of the two files using the ls command:

$ ls –l

Output

...
-rw-rw-r-- 1 james james    0 Jul 16 09:10 demo1.txt
-rw-rw-r-- 1 james james    0 Jul 16 09:11 demo2.txt
...

You can also copy multiple files. First create a directory named 'demos':

$ mkdir demos

You can them move 'demo1.txt' and 'demo2.txt' file using the syntax below:

$ cp *.txt demos/

The above syntax will copy all files that end with a '.txt' extension

To confirm if the copying was successful, you need to cd to the demos directory and issue the ls -l command to list the directory contents:

$ cd demos
$ ls -l 

Output

-rw-rw-r-- 1 james james 0 Jul 16 09:13 demo1.txt
-rw-rw-r-- 1 james james 0 Jul 16 09:13 demo2.txt

Remember to go back to the working directory and navigate out of the demo directory by typing:

$ cd ..

10: Linux mv Command

Linux mv command is used to move files and directories from one location to another. If you try to move the file to the same directory, the file will be renamed instead.

For instance, if you have a file named demo3.txt and you issue the command to move it to demo4.txt, the file will be renamed.

The mv command has the below syntax:

$ mv 

Example:

$ mv demo3.txt demo4.txt

11: Linux man command

This command displays the user manual page and shows more information about using a command. For instance, if you issue the man command together with a mv command, you will get the following output:

$ man mv

Output

MV(1)                                                 User Commands                                                 MV(1)
NAME
       mv - move (rename) files
SYNOPSIS
       mv [OPTION]... [-T] SOURCE DEST
       mv [OPTION]... SOURCE... DIRECTORY
       mv [OPTION]... -t DIRECTORY SOURCE...
DESCRIPTION
       Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.
       Mandatory arguments to long options are mandatory for short options too.

12: Linux echo Command

You can use the Linux echo command to display text on your terminal window or redirect the output to a file.

$ echo sample text

Output

sample text

If you want to redirect the output to a file name text1.txt, use the syntax below:

$ echo sample text > text1.txt

Please note the file will be created if it's not there.

Also to append more text to an existing file, use to greater than symbol as shown below:

$ echo additional sample text >> text1.txt

You can also print all the contents of a directory using the echo command to supplement the ls command as shown below

$ echo *

13: Linux cat Command

The cat command reads files and displays the content on a standard output. You can also concatenate information from multiple files and display the combined output on the screen.

For instance to view the content of the text1.txt file that we created above, we can use the command below

$ cat text1.txt

Output

sample text
additional sample text

To concatenate the text of two files, use the syntax below:

$ cat text1.txt text2.txt

14: Linux more Command

The more command displays the content of a file one screen at a time. This is a very powerful command for displaying contents of files with large output that cannot fit on the screen.

To view the content of a file named text1.txt, use the command below:

$ more text1.txt

Output

sample text
additional sample text

15: Linux grep Command

You can use the grep command to search text on a file name:

The general syntax is:

$ grep 'keyword' 

For example, let's search for the word 'sample' in a file named 'text1.txt':

$ grep sample text1.txt

Output

sample text
additional sample text

As you can see above, our search keyword was found on the file and is highlighted in red.

16: Linux history Command

To see a list of commands that have been executed by the current logged in user, use the history command.

$ history

Sample Output

1    ls -a
2    rm *.txt
3    rm -r demos
4    rm test
5    ls -a
6    ls
7    ls -p
...

The list has line numbers. You can use the syntax below to repeat a command from the history:

$ !

For instance to run command number 5, ls -a, we can use the command below:

$ !5

17: Linux chown Command

This is an administrative command used to change the ownership of Linux files.

Syntax:

$ chown .

For instance, if you have a directory named demo10 but you want it to be owned by a different user named 'joseph', use the syntax below:

First create the directory:

$ mkdir demo10

Then, change ownership:

$ sudo chown joseph.joseph demo10

If you run the command ls -l you will see the directory is now owned by the user 'joseph'

...
drwxrwxr-x 2 joseph  joseph  4096 Jul 16 10:08 demo10
...

Please note you must be have the correct privilege to change the ownership of a file:

18: Linux chmod Command

You can change the permissions of a file by issuing a chmod command:

General syntax

$ chmod options 

For instance, to issue full permissions for all users to the demo10 directory, we can use the command below:

$ chmod 777 demo10

Please note you must be the owner of the file/directory to make changes permissions, otherwise, run the command using sudo.

19: Linux free Command

To see the total available and used RAM as well as swap space, use the free command.

$ free –h

Output

              total        used        free      shared  buff/cache   available
Mem:           985M        302M         72M        2.3M        610M        496M
Swap:            0B          0B          0B

This command is useful when troubleshooting memory related issue on your Alibaba Cloud ECS VPS.

20: Linux df Command

Use the df command to list the total amount of available disk space. If you are running out of space or probably want to scale up, you can monitor the disk usage using this command.

$ df –f

Sample Output

Filesystem      Size  Used Avail Use% Mounted on
udev            464M     0  464M   0% /dev
tmpfs            99M  640K   98M   1% /run
/dev/vda1        25G  3.4G   20G  15% /
tmpfs           493M     0  493M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           493M     0  493M   0% /sys/fs/cgroup
tmpfs            99M     0   99M   0% /run/user/1000

From the above report, the available disc space is 20 gigabytes.

21: Linux date Command

You can view and manipulate date and time in a Linux server using the date command. To view the current system date, use the command below:

$ date

Output

Mon Jul 16 10:26:39 EAT 2018

To set your server date and time manually, use the command below:

$ date --set="YYYYMMDD HH:MM"

Example

$ sudo date --set="20180716 10:30"

22: Linux sudo Command

In Linux sudo is an acronym for 'super user do'. This command is useful when running commands that need elevated privileges (e.g. changing date) especially when installing programs or changing configuration files.

23: Linux reboot Command

Apart from the flexibility of installing custom applications, an Alibaba Cloud ECS VPS allows you to reboot your system especially if you want to apply new changes to the system. To do this, use the command below:

$ sudo reboot

Conclusion

Those are the basics commands that are very helpful when managing your Alibaba Cloud ECS instance running a Linux distribution. We have covered major commands which will be very useful in administering your server.

You can also dig deeper and learn more commands related to the Linux distribution on the Alibaba Cloud Getting Started guides. As always, you can test Alibaba Cloud service by creating an account. Sign up now to try out Alibaba Cloud products and enjoy $300 worth in Free Trial.

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