7 commands that don’t work on Linux and why you need to know!

As a Linux user, you may have mastered many commonly used commands, but did you know that some commands are not applicable to Linux systems? These commands may be common on other operating systems, but they don't work on Linux. Today, we will introduce 7 commands that do not run on Linux to let you understand why these commands cannot run on Linux.

So let’s start with this list of Linux commands that you should never run, and again I say do so with caution:

Linux commands you should never run

1- Format system disk

Linux administrators often use this command to format and assign a file system to a newly created disk partition. However, if used irresponsibly, it may also format data on the disk,

$ mkfs.ext4 /dev/sda

So when using this command, make sure you have selected the desired disk partition.

2- Delete the /etc or /boot directory

/etc contains all configuration files of the system, and /boot contains all kernel, InitRD and GRUB related files that are required for system startup. Deleting these folders will prevent your system from booting,

$ rm -rf /etc
$ rm -rf /boot

Another way to remove configuration files from your system and render your system unrecoverable is to use the following command,

$ find / -iname "*.conf" -exec rm -rf {} ;

This will find and delete all files (configuration files) ending with .conf.

3- Delete the entire file system

Most of you probably know this command, it looks like this

$ rm -rf /

This will delete the entire file system from your server, deleting every byte of data on the disk.

4- Fork Bomb

This command will create copies of itself without limit, which will quickly use up all the memory and CPU of the system, causing the system to crash.

$ :(){ :|:& };:

This may also cause disk corruption.

5- Fill the disk with random data

$ dd if=/dev/urandom of=/dev/sda

This will fill the disk with random data. Another variation of this command overwrites the original data multiple times,

$ shred /dev/sda

Actually, this command is a useful tool, especially when you are getting rid of an old disk and don't want the data from the old disk to fall into the wrong hands (another method learned in the movie is that you can drill holes).

6- File permission confusion

All the above commands involve deleting or overwriting data. However, there are ways to use file permissions to render a system unusable. The first command is,

$ chmod -Rv 000 /

This command will remove all file permissions from all files or folders on the system. Since no one can access the files and folders, they will not be able to access them. This also leads to another way of writing the above command,

$ chown -R nobody:nobody /

This will also achieve the same output as the first command. Now the second file permissions command is actually the opposite of the first command,

$ chmod -R 777 /

This will change the permissions of all files and folders to world-writable. I'm sure you can imagine what would happen in this situation.

In this article, we introduce 7 commands that do not work on Linux. These commands may be common on other operating systems, but they do not work on Linux. Understanding the reasons for these commands is very important for Linux users, because it can help us better understand and master the Linux system. I hope this article has inspired you and given you a deeper understanding of the Linux system.

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