https://github.com/mendhak/wasm-tutorials-learn

https://github.com/mendhak/wasm-tutorials-learn

Last synced: 9 months ago
JSON representation

• Host: GitHub
• URL: https://github.com/mendhak/wasm-tutorials-learn
• Owner: mendhak
• Created: 2023-12-23T22:06:45.000Z (about 2 years ago)
• Default Branch: master
• Last Pushed: 2023-12-26T18:41:28.000Z (about 2 years ago)
• Last Synced: 2025-02-12T06:38:44.576Z (11 months ago)
• Language: WebAssembly
• Size: 7.81 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

          


## C

Following the [WASI tutorial](https://github.com/bytecodealliance/wasmtime/blob/main/docs/WASI-tutorial.md), with some modifications. 

Basic C code, compiled to wasm with clang, run with wasmtime. 

Get the clang compiler. 

    wget https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-21/wasi-sdk-21.0-linux.tar.gz

    tar xf wasi-sdk-21.0-linux.tar.gz

    ./wasi-sdk-21.0/bin/clang demo.c -o demo.wasm

Build the .wasm file. 

    ./wasi-sdk-21.0/bin/clang demo.c -o demo.wasm

Get wasmtime.

    wget https://github.com/bytecodealliance/wasmtime/releases/download/v16.0.0/wasmtime-v16.0.0-x86_64-linux.tar.xz

    tar xf wasmtime-v16.0.0-x86_64-linux.tar.xz

Run the file which copies a file from one place to another. 

    echo "Hello world" > hello.txt

    ./wasmtime-v16.0.0-x86_64-linux/wasmtime --dir=. demo.wasm ./hello.txt output.txt

    cat output.txt

## Web Assembly Text

Following [this MDN tutorial](https://developer.mozilla.org/en-US/docs/WebAssembly/Text_format_to_wasm).

Directly execute the text. 

    ./wasmtime-v16.0.0-x86_64-linux/wasmtime simple.wat

Use `wabt` to convert the web assembly text to binary. 

    wget https://github.com/WebAssembly/wabt/releases/download/1.0.34/wabt-1.0.34-ubuntu.tar.gz

    tar xf wabt-1.0.34-ubuntu.tar.gz

    ./wabt-1.0.34/bin/wat2wasm simple.wat

    ./wasmtime-v16.0.0-x86_64-linux/wasmtime simple.wasm

View it in an HTML file

    python3 -m http.server

    firefox http://localhost:8000/simple.html

## Using emscripten

Following [this MDN tutorial](https://developer.mozilla.org/en-US/docs/WebAssembly/C_to_wasm).

Compile to a packaged HTML, using the emscripten Docker image

    docker run --rm -v $(pwd):/src -u $(id -u):$(id -g) emscripten/emsdk emcc hello.c -o hello.html 

Run the resulting HTML file

    

    python3 -m http.server

    firefox http://localhost:8000/output/hello.html

Compile to a packaged Node JS file, using the emscripten Docker image

    docker run --rm -v $(pwd):/src -u $(id -u):$(id -g) emscripten/emsdk emcc hello.c -o output/hello2.js

    node output/hello2.js

Compile hello3 to a template HTML file using the emscripten docker image 

    docker run --rm -v $(pwd):/src -u $(id -u):$(id -g) emscripten/emsdk emcc -o output/hello3.html hello3.c --shell-file shell_minimal.html -s NO_EXIT_RUNTIME=1 -s "EXPORTED_RUNTIME_METHODS=['ccall']"

    python3 -m http.server

    firefox http://localhost:8000/output/hello3.html

## Todo - Docker = WASM

https://docs.docker.com/engine/alternative-runtimes/#wasmtime

Running WASM in Docker without Docker Desktop.