[Linux] Check os version in Linux

> cat /etc/os-release

root@58d01b6b8b17:/# cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.2 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.2 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

[Linux] Replace one substring for another string in shell script

first="I love me and Mary"
second="conan"
first=${first/me/$second}

[Linux] How to get and set SW/HW date in linux

get date
- Software
> date


- Hardware
hwclock


set date
- Software
> date


- Hardware
hwclock