How do I use the preamble.js file in emscripten?

Question

I'm trying to get started with a small web-application with webassembly, and I'm using emscripten. Emscripten has this "preamble.js" file that " provide programmatic access for interacting with the compiled C code ". My problem is that I don't understand how to actually use this file. It's not javascript code so my browser can't load it, and it's not C/C++ code so my compiler can't compile it. So what do I do with it?

Sorry if this is painfully obvious or documented somehwere, but I can't see it.

Answer 1

preamble.js by itself can't be loaded in a browser, but when you use emscripten to generate a JavaScript (or HTML) output file (eg by invoking emcc foo.c -o foo.js ), it will include a preprocessed version of the preamble along with your asm.js code in the output file. (Or if you use WebAssembly, it will also generate a foo.wasm file to go along with foo.js ). The output foo.js file should be loadable in the browser (or eg node.js if it doesn't use web APIs).