System

4 ways to create an empty file:

$ touch myFile
$ echo '' > myfile
$ cp /dev/null myFile
$ truncate --size 0 myFile

Journaling file system

ext3/4, xfs and Btrfs

Switch to another user without password

useradd foo
visudo

And in visudo, add this line:

gbucchino ALL=NOPASSWD: /bin/su - foo

You can test it:

sudo su - foo

Create a service with systemd

Password manager

I use pass as password manager.

WiFi network interface

In this section, we will configure the WiFi interface and to connect automatically to the endpoint WiFi. First,

wpa_passphrase mySSID "passphrase" >> /etc/wpa_supplicant/wpa_supplicant-wlp0s20f3.conf
systemctl restart wpa_supplicant@wlp0s20f3.service
systemctl enable wpa_supplicant.service
systemctl enable wpa_supplicant@wlp0s20f3.service

We will enable the service:

$ cat /etc/systemd/network/00−wireless.network
[Match]
Name=wlp0s20f3
[Network]
DHCP=yes
$ systemctl enable systemd−networkd.service

Privilege

Then use the chmod command to make all files created within that directory belong to the group the directory belongs to with

sudo chmod g+s /path/to/your/dir