Display

The OS type variable

echo "$OSTYPE"
OS Example value
Linux linux-gnu
macOS darwin19.0

The uname command

See uname cheatsheet.

$ uname

e.g.

OS Example uname value
Linux Linux
macOS Darwin

Using uname in a conditional using contains and -s flag. I’ve seen this approach used before.

if [[ "$(uname -s)" =~ 'Linux' ]]; then
  echo 'Linux!'
fi

Set boolean

This was based on a Grails quickstart app which uses case and uname.

IS_MAC=false
IS_LINUX=false

case "$(uname)" in
  Darwin* )
    IS_MAC=true
    ;;
  Linux* )
    IS_LINUX=true
    ;;
esac

Example use:

if [[ $IS_MAC == 'true' ]]; then
  echo 'Hello, macOS!'
fi

Inline control flow

Perform a check inline to produce a string. Note this could be improved by first storing a value.

$ echo "Hello $([[ "$OSTYPE" == darwin* ]] && echo 'Mac')"
  • Result if Mac: Hello Mac
  • Result if not Mac: Hello

Release

$ less /etc/*release

Example for Linux Lite 5, which uses Debian and Ubuntu:

  • lsb-release 
      DISTRIB_ID=Ubuntu
  DISTRIB_RELEASE=20.04
  DISTRIB_CODENAME=focal
  DISTRIB_DESCRIPTION="Linux Lite 5.0"
  • os-release 
      NAME="Ubuntu"
  VERSION="20.04 LTS (Focal Fossa)"
  ID=ubuntu
  ID_LIKE=debian
  PRETTY_NAME="Linux Lite 5.0"
  VERSION_ID="20.04"
  HOME_URL="https://www.ubuntu.com/"
  SUPPORT_URL="https://help.ubuntu.com/"
  BUG_REPORT_URL="https://bugs.launc
  hpad.net/ubuntu/"
  PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
  VERSION_CODENAME=focal
  UBUNTU_CODENAME=focal

On an AWS EC2 instance:

  • /etc/os-release 
      NAME="Amazon Linux"
  VERSION="2"
  ID="amzn"
  ID_LIKE="centos rhel fedora"
  VERSION_ID="2"
  PRETTY_NAME="Amazon Linux 2"
  ANSI_COLOR="0;33"
  CPE_NAME="cpe:2.3:o:amazon:amazon_linux:2"
  HOME_URL="https://amazonlinux.com/"
  • /etc/system-release 
      Amazon Linux release 2 (Karoo)

Check OS flavor

Check if Linux Lite

Linux Lite uses a text file which includes the version.

IS_LINUX_LITE=$([[ -f /etc/llver ]] && echo 'true' || echo 'false')

if [[ -f /etc/llver ]]; then
  IS_LINUX_LITE=true
else
  IS_LINUX_LITE=false
fi