local component=require("component")
local shell=require("shell")

local args=shell.parse(...)
if#args==0 then
io.write("Usage: primary <type> [<address>]\n")
io.write("Note that the address may be abbreviated.\n")
return 1
end

local componentType=args[1]

if#args>1 then
local address=args[2]
if not component.get(address)then
io.stderr:write("no component with this address\n")
return 1
else
component.setPrimary(componentType,address)
os.sleep(0.1)
end
end
if component.isAvailable(componentType)then
io.write(component.getPrimary(componentType).address,"\n")
else
io.stderr:write("no primary component for this type\n")
return 1
end