module PlatformInfo


	require 'open3'

	a = Open3.popen3('uname -m');
	a[1].each_line {|x|
		UNAME_ARCH=x.chomp!
	}

	a = Open3.popen3('uname -r');

	a[1].each_line {|x|
		UNAME_VERS=x.chomp
	}

	a = Open3.popen3('uname -s');
	a[1].each_line {|x|
		UNAME_SYST=x.chomp
	}

	$ret_arch = String.new(nil.to_s);
	$ret_dist = String.new(nil.to_s);
	$ret_syst = String.new(nil.to_s);

	def guess_arch

		unless $ret_arch.is_a?(NilClass)
			return $ret_arch
		end

		case UNAME_SYST
		when 'FreeBSD'
			ret = UNAME_ARCH;
		when 'NetBSD'
			ret = UNAME_ARCH;
		when 'OpenBSD'
			case UNAME_ARCH
			when 'sun3'
				ret = 'm68k';
			when 'mvme68k'
				ret = 'm68k';
			when 'mac68k'
				ret = 'm68k';
			when 'amiga'
				ret = 'm68k';
			else
				ret = UNAME_ARCH;
			end
		when 'Linux'
			case UNAME_ARCH
			when /ppc.*/
				# This should handle ppc -> powerpc
				# and ppc64 -> powerpc64
				ret = UNAME_ARCH.sub('ppc', 'powerpc');
			when 'parisc64'
				ret = 'hppa64';
			else
				ret = UNAME_ARCH;
			end
		when /.*DOS$/
			# djgpp
			ret = 'i386';
		else
			ret = '';
		end

		$ret_arch = ret;
		return ret;
	end

	def guess_dist

		unless $ret_dist.empty?
			return $ret_dist
		end

		ret = 'unknown';

		case UNAME_SYST
		when 'FreeBSD'
			unless ENV['SMART_ASS'].is_a?(NilClass)
				ret = 'ontopofmydesk';
			end
			unless ENV['PORT_BUILD'].is_a?(NilClass)
				ret = 'portbld';
			end
		when 'Linux'
			# GNU config.guess does dist=pc for ia32 boxen
			if $ret_arch =~ /^i.86$/
				ret = 'pc';
			end
		when /.*DOS$/
			# djgpp core
			ret = 'pc';
		end

		$ret_dist = ret;
		return ret;
	end

	def guess_os

		unless $ret_syst.empty?
			return $ret_syst
		end

		ret = UNAME_ARCH

		case UNAME_SYST
		when 'FreeBSD'
			ret = 'freebsd' + UNAME_VERS.sub(/-.*$/, '');
		when 'OpenBSD'
			ret = 'openbsd' + UNAME_VERS
		when 'NetBSD'
			# NetBSD (nbsd) targets should (where applicable) match one or
			# more of the tupples: *-*-netbsdelf*, *-*-netbsdaout*,
			# *-*-netbsdecoff* and *-*-netbsd*.  For targets that recently
			# switched to ELF, *-*-netbsd* would select the old
			# object file format.  This provides both forward
			# compatibility and a consistent mechanism for selecting the
			# object file format.

			ret = 'netbsd';
		when 'Linux'
			ret = 'linux-gnu';
			# Does anyone still use a.out or coff on ia32? Nah.
		when /.*DOS$/
			# djgpp-core
			ret = 'msdosdjgpp';
		end

		$ret_syst = ret;
		return ret;
	end

 	def guess
		return guess_arch + '-' + guess_dist + '-' + guess_os
	end

	module_function :guess_arch, :guess_dist, :guess_os, :guess
end