How to read files on the device?

[adorableparker]

I'm trying to make a mod that can backup blueprints by copying the "blueprint-storage.dat" file regularly, but Factorio doesn't seem to allow "io.open()" to read the file. What should I do?

[eradicator]

What should I do?

Factorio mods are sandboxed. Access to any kind of non-game data is not allowed, to keep determinisim across all platforms. You'll have to do it as an external script, not as a mod.