Umm ifconfig has been deprecated long enough to drink in many countries (19 years); iproute2 has been around long enough to drink in the USA, 21 years.
Please update your article to use 'ip -a' and not 'ifconfig'.
From Wikipedia:. ifconfig for Linux is part of the package net-tools, released as the latest version 1.60 on 15 April 2001. Many Linux distributions have deprecated the use of ifconfig and route in favor of the software suite iproute2, such as ArchLinux or RHEL since version 7, which has been available since 1999 for Linux 2.2."
Adding a 'T' to the options of df even gives you the filesystem type; which is useful as well. Is it ext(2/3/4)? Xfs?
'df -hT' gives you a nice human-readable numerical output as well as informs you of the filesystem type.