How to capture stdout and stderr?

[HuakunShen]

console.log works and could print to console.
I wonder how to capture stdout and stderr?
To my understanding, the js script is running in the same thread as the rust program, so there is no stdout.
But what if I need the data from stdout and stderr?

[rscarson]

So under the hood, I initialize the console stuff with op_print which goes directly to stdio

I think the easiest way would be to replace that op with one that can write to a string buffer instead.

It's come up at least once before so I may just include it as a feature in the next release

I'll replace op_print with one that prints to an object in the store that can be set to go to string buffers instead of stdio buffers, then add a function to the runtime to toggle it