#!/bin/sh
#
# Functions shared by several scripts
#
# Copyright (c) 2013-2016 MegaGlest Team under GNU GPL v3.0+

function detect_system {
# Determine distro title, release, codename
#
# Input: 
#   -/-
#
# Output:
#   No direct output, but the following variables are set:
#   lsb: whether (1) or not (0) system information was retrieved from 'lsb_release'
#   distribution: detected Linux distribution (string)
#   release: detected distribution release / version (string)
#   codename: codename of the detected Linux distribution (string)
#   architecture: detected machine architecture (string)

	if [ "$(which lsb_release)" = "" ]; then
		lsb=0
		release='unknown release'
		if [ -e "/etc/os-release" ]; then
			distribution="$(cat "/etc/os-release" | grep '^ID=' | awk -F '=' '{print $2}' \
			    | awk '{print toupper(substr($0,1,1))substr($0,2)}')"
			codename="$(cat "/etc/os-release" | grep '^PRETTY_NAME=' | awk -F '"' '{print $2}')"
			# example output ^ on debian testing: "Debian GNU/Linux stretch/sid"
		elif [ -e /etc/debian_version ]; then
			distribution='Debian'
			codename="$(cat /etc/debian_version)"
		elif [ -e /etc/SuSE-release ]; then
			distribution='SuSE'
			codename="$(cat /etc/SuSE-release)"
		elif [ -e /etc/redhat-release ]; then
			if [ -e /etc/fedora-release ]; then
				distribution='Fedora'
				codename="$(cat /etc/fedora-release)"
			else
				distribution='Redhat'
				codename="$(cat /etc/redhat-release)"
			fi
		elif [ -e /etc/fedora-release ]; then
			distribution='Fedora'
			codename="$(cat /etc/fedora-release)"
		elif [ -e /etc/mandrake-release ]; then
			distribution='Mandrake'
			codename="$(cat /etc/mandrake-release)"
		else
			distribution='unknown distribution'
			codename='unknown codename'
		fi
	else
		lsb=1
		distribution="$(lsb_release -i | awk -F':' '{ gsub(/^[ \t]*/,"",$2); print $2 }')"
		release="$(lsb_release -r | awk -F':' '{ gsub(/^[  \t]*/,"",$2); print $2 }')"
		codename="$(lsb_release -c | awk -F':' '{ gsub(/^[ \t]*/,"",$2); print $2 }')"

		# Some distribution examples:
		#
		# OpenSuSE 11.4
		#   LSB Version:    n/a
		#   Distributor ID: SUSE LINUX
		#   Description:    openSUSE 11.4 (x86_64)
		#   Release:        11.4
		#   Codename:       Celadon
		#
		# OpenSuSE 12.1
		#   LSB support:  1
		#   Distribution: SUSE LINUX
		#   Release:      12.1
		#   Codename:     Asparagus
		#
		# Arch
		#   LSB Version:    n/a
		#   Distributor ID: archlinux
		#   Description:    Arch Linux
		#   Release:        rolling
		#   Codename:       n/a
		#
		# Ubuntu 12.04
		#   Distributor ID: Ubuntu
		#   Description:    Ubuntu 12.04 LTS
		#   Release:        12.04
                #   Codename:       precise
	fi
	architecture="$(uname -m)"
}