#!/bin/bash
# Display current operating system.

rel=`uname`

if [ "$rel" = "Darwin" ]
then
  echo mac
  exit 0
fi

if [ "$rel" != "Linux" ]
then
  echo "Unknown platform"
  exit 1
fi

if [ -f /etc/os-release ]
then
  . /etc/os-release
  
  if [ "$ID" = "rhel" ] || [ "$ID" = "centos" ]
  then
    ID=el
    ver=`echo $VERSION_ID | awk -F'.' '{print $1}'`
    echo $ID$ver
    exit 0
  elif [ "$ID" = "fedora" ]
  then
    ID=fc
  fi
  echo $ID$VERSION_ID
  exit 0
elif [ -f /etc/redhat-release ]
then
  os=`cat /etc/redhat-release | awk '{print $1}'`

  if [ "$os" = "Fedora" ]
  then
    prefix="fc"
  else
    prefix="el"
  fi
  ver=`cat /etc/redhat-release | awk '{for (i=1; i<NF; i++) {if ($i == "release") {print $(i+1); break;}}}' | awk -F'.' '{print $1}'`
  echo $prefix$ver
  exit 0
elif [ -f /etc/issue ]
then
  os=`cat /etc/issue | awk '{print $1}'`

  if [ "$os" = "Debian" ]
  then
    ver=`cat /etc/issue | tr -d '\n' | awk '{print $3}' | awk -F'.' '{print $1}'`
    echo debian$ver
    exit 0
  elif [ "$os" = "Ubuntu" ]
  then
    ver=`cat /etc/issue | tr -d '\n' | awk '{print $2}' | awk -F'.' '{printf("%s.%s\n",$1,$2)}'`
    echo ubuntu$ver
    exit 0
  fi
fi

echo "Unknown platform"
exit 1    
