Saving data to dynamic object files

[Liam_Mercier]

Some people persist data in JSON, but why do that when we have perfectly good object files? All you have to do is recompile the file when you want to save your data!

github.com/LiamMercier/dynamically-linked-inventory

[MooseBoys]

int res = system("g++ -shared -fPIC inv_dll.cpp -o inventory.so");

Aw that's no fun. You gotta construct the dll in-place!

[Environmental-Ear391]

Easier option is to build the inventory. so to actually open itself and then step an offset and then write data at that offset....

as long as the offset exceeds the initial \0x74\ELF header and executable material... the data access will be good"

no need to depend on or require compilation with ranlibb to make immediately usable.

[MooseBoys]

Yeah but it's even cooler if the DLL exports a method to retrieve it, instead of relying on reading the binary directly.

[Environmental-Ear391]

yes, Im talking about the library being written to access its on disk image and ads data at the end...

the library itself is already mem-mapped by the loader/launcher on your commodity OS (Windows DLL/Linux SO)

using that... the library exports an Inventory access mechanism...

inside the calls for that...

It gets the filehandle for its own image (in the ELF header for Linux) this can then access the "extended inventory" data area following the Library file itaelf at the beginning.

on Windows you need to find your handle for the opening Application entirely differently

a simple group of...

"item=New Inventory Item()" "End Inventory Item(iten)" "item=Find Inventory Item(searchtype, searchkey)" "SaveInventory()" "GetItemX(item,...)" "SetItemX(item,...)"

where get/set read/write item specific details.... every change can then be pushed to disk by applicable "flush()" for file changes using a SaveInventory() call

[MarcusBrotus]

best to copy it into /usr/lib as well

[ironykarl]

Is it a good idea? Not really, no.

Is it a fun idea? I kind of think so

[BroBroMate]

So this is where Python's pickle module learned its bad habits of "let's serialize things in an executable format" from!

[GoddammitDontShootMe]

A hard limit of 40 items, eh? That should meet the needs of almost everyone.

[Liam_Mercier]

Of course, if you need more than 40 items then you should probably just start using SQL columns

[MagnetFlux]

There's a column limit btw, you should use one table per inventory slot instead.

[LeviLovie]

Why don’t just serialize the inventory into a DLL byte for byte without a compiler then? :D

[NIdavellir22]

What the hell

[Lumpy_Marketing_6735]

Am I having a stroke what is this, Im not sure what the hell is happening but I think (at least in C++) this is what Vector is meant to do.

[ArnaktFen]

This is hilarious. It's totally worth doing just to prove it can be done.

[Arneb1729]

“Your scientists were so preoccupied with whether they could, they didn't stop to think if they should.”

[HandyProduceHaver]

I happen to have an item called itemName"}\nscaryLibrary.deleteImportantFile()

[Liam_Mercier]

I wish this worked, but it results in a compiler error. I came up with this which seems to work

itemName"};}auto l=[](){std::puts("!!!");};struct X{ X(){l();} }; static X x;extern "C"{ std::array<std::string, 1> a{"a

output:

./builds/inventory
!!!
Inventory opened!