local fs=require("filesystem")
local shell=require("shell")

local args,options=shell.parse(...)

if#args<1 then
io.write("Usage: umount [-a] <mount>\n")
io.write(" -a  Remove any mounts by file system label or address instead of by path. Note that the address may be abbreviated.\n")
return 1
end

local proxy,reason
if options.a then
proxy,reason=fs.proxy(args[1])
if proxy then
proxy=proxy.address
end
else
local path=shell.resolve(args[1])
proxy,reason=fs.get(path)
if proxy then
proxy=reason
if proxy~=path then
io.stderr:write("not a mount point\n")
return 1
end
end
end
if not proxy then
io.stderr:write(tostring(reason)..'\n')
return 1
end

if not fs.umount(proxy)then
io.stderr:write("nothing to unmount here\n")
return 1
end