Linux kali 5.9.0-kali5-amd64 #1 SMP Debian 5.9.15-1kali1 (2020-12-18) x86_64 GNU/Linux in Oracle Virtual Box

Hello everyone,

I am going trough the linux basics for hackers book and in text manipulation they use sed command.
I am trying it now and it does not work.

cat original file (keyboard2)

# KEYBOARD CONFIGURATION FILE


# Consult the keyboard(5) manual page.


XKBMODEL="pc105"
XKBLAYOUT="fr"
XKBVARIANT=""
XKBOPTIONS=""


BACKSPACE="guess"



When I run sed s/fr/us/ keyboard2 displays this

# KEYBOARD CONFIGURATION FILE


# Consult the keyboard(5) manual page.


XKBMODEL="pc105"
XKBLAYOUT="us"
XKBVARIANT=""
XKBOPTIONS=""


BACKSPACE="guess"

But when I cat keyboard 2 again I am back to original file.

Can anyone hel me see what I am missing here ?

Thank you so much.