Large Object

Hi! , I want to ask you about large objects or BLOBs

I need to know the size of a large object that I have already know its indice number.

For example ,

One of my large objects in my database is indicated with xinv223345 and xinc223345

if I use this command

select lo_export(223345,'/tmp/myfile')

I can easily export this large object to my file system and see its size by " ls " command. BUT , i want to know this object's size whitout exporting it to my file system.

As a brief , Is there any postgresql command or statement that gives you a large object's SIZE which is in your database ?

Or you can advise me perl or C modules.

Thanks alot!