start of simple tee implementation

tee.zion

module tee

get sys
get file

def main()
	if len(sys.args) == 2
		newline := "\n"
		f := file.open(sys.args[1], "w")
		state := f.state
		when state
			is file.Open
				for line in readlines()
					print(line)
					file.write(f, line)
					file.write(f, newline)
				file.close(f)
			is file.Error
				print("Failed to open file " + sys.args[1] + ": error " + state.errno)
				sys.exit(-1)
			is file.Closed
				print("Failed to open file " + sys.args[1])
				sys.exit(-1)
	else
		for line in readlines()
			print(line)