#!/bin/sh

# Shave and a Haircut
# (c) 2019 Epic Games
# US Patent 6720962

case `uname -s` in
    Linux)
	sysInfoFile=""
	osVersion=""
	if [ -r /etc/issue ]; then
	    sysInfoFile=/etc/issue
	    osVersion=`grep "release" ${sysInfoFile} | sed 's/^.*release \([0-9][0-9]*[.]*[0-9]*\).*$/\1/'`
	fi

	if [ "${osVersion}" = "" -a -r /etc/system-release ]; then
	    sysInfoFile=/etc/system-release
	    osVersion=`grep "release" ${sysInfoFile} | sed 's/^.*release \([0-9][0-9]*[.]*[0-9]*\).*$/\1/'`
	fi

	if [ "${osVersion}" != "" ]; then
	    if grep "Fedora" ${sysInfoFile} >/dev/null; then
	        osType=fc
	    elif grep "CentOS" ${sysInfoFile} >/dev/null; then
		osType=ce
	    elif grep "Debian" ${sysInfoFile} >/dev/null; then
		osType=deb
		osVersion=`grep "Debian" ${sysInfoFile} | sed 's/^[^0-9]*\([0-9.]\+\)[^0-9]*$/\1/'`
	    else
		osType=rh
	    fi

	    echo ${osType}${osVersion}
	else
	    echo "getos:error: cannot determine Linux version." >&2
	    echo ""
	fi
	;;

    Darwin)
    	osVersion=`sw_vers -productVersion`
	echo "osx${osVersion}"
	;;

    *)
    	echo "Unrecognized OS type '`uname -s`'." >&2
	echo ""
	;;
esac