Linux OS version

os-ver.sh

#!/bin/bash
  
if [ -f /etc/os-release ]; then
    # freedesktop.org and systemd
    . /etc/os-release
    OS_ID=$ID
    #OS=$NAME
    #VER=$VERSION_ID
fi

case "$OS_ID" in
    centos)
        RESULT=`cat /etc/centos-release`
        ;;
    debian)
        RESULT="Debian "`cat /etc/debian_version`
        ;;
    ubuntu)
        RESULT=$PRETTY_NAME
        ;;
    alpine)
        RESULT=$NAME" "`cat /etc/alpine-release`
        ;;
    *)
        RESULT=$(umane -s)" "$(uname -r)
        ;;
esac

echo "$RESULT"