Funny side of Linux

Usually people think as Linux as a serious OS. But it has some inbuilt commands to make you smile.
here It goes::::

1. $yes
This command echoes your string repeatedly until killed
e.g. -> $yes this will be repeated indefinetly
2. $wall
This command will display your msg to all your logged user.
e.g.-> $wall hi to all
"hi to all" will be received by all of the user logged in through terminal
3. Black hole of linux :: /dev/null
redirect any output to this file and and it will return true that file has been written but this file is always null{blank}
4. file filled with NULL bytes :: /dev/zero
Accepts and discards all input; produces a continuous stream of NULL bytes. Can be used for low level disc formatting or erasing hardDisk data permanently
e.g. #dd if=/dev/zero of=/dev/sda bs=1M
5. file filled with random bytes
Accepts and discards all input; produces a continuous stream of random bytes. Can be used to wipe out hardDisk more securely.
#dd if=/dev/urandom of=/dev/sda bs=1M
6. A file with no space to write :: /dev/full
Produces a continuous stream of NULL bytes when read, and returns a "write error: No space left on device"  message when written to
7. bc {indian readers only}
it's actually binary calculator.made for calculations in terminal
8. toilet
it is not installed by default . so apt-get helps you
$sudo apt-get install toilet
e.g. -> $toilet --gay You are so gay
9.sl {steam locomative}
shows a running train in terminal
$sudo apt-get install sl
10. oneko
this makes mouse pointer as jerry and tom keeps running behind it
$sudo apt-get install oneko
11. $man woman
you will output as "No manual entry for woman"
12. $make love
make: *** No rule to make target `love'.  Stop.
13. cmatrix
matrix in your terminal
$sudo apt-get install cmatrix