Small issue with the USER environment variable:
$ echo $USER
thib
$ sudo sh -c 'echo $USER'
thib
$ sudo -i sh -c 'echo $USER'
root
Rather than recommending users to use sudo --login / -i, use the (very
widespread/portable) id program to retrieve the effective user ID
instead and don't change the recommendation.
$ id -u
1000
$ sudo id -u
0
$ sudo -i id -u
0
