The “wat2wasm” command is used to convert a file from the WebAssembly text format to the binary format. It is a part of the WebAssembly Binary Toolkit (WABT) and can be used to parse, check, and convert WebAssembly files.

Use case 1: Parse and check a file for errors

Code:

wat2wasm file.wat

Motivation:

Parse and check a WebAssembly file for errors before further processing or executing the file.

Explanation:

• file.wat: The WebAssembly file to be parsed and checked.

Example Output:

Parsed module ok.

Use case 2: Write the output binary to a given file

Code:

wat2wasm file.wat -o file.wasm

Motivation:

Convert a WebAssembly file from the text format to the binary format and save the binary output to a specified file.

Explanation:

• file.wat: The WebAssembly file to be converted.
• -o file.wasm: Specifies the output file name where the binary representation of the WebAssembly module will be saved.

Example Output:

Binary output written to file.wasm.

Use case 3: Display simplified representation of every byte

Code:

wat2wasm -v file.wat

Motivation:

Get a simplified representation of every byte in the WebAssembly binary file.

Explanation:

• -v: Specifies verbose output, which includes a simplified representation of every byte in the WebAssembly binary file.
• file.wat: The WebAssembly file to be converted.

Example Output:

File size: 133 bytes
Displaying simplified representation of every byte:
0x00 0x61 0x73 0x6D 0x01 0x00 0x00 0x00 ...

Conclusion:

The “wat2wasm” command is a useful tool for working with WebAssembly files. It allows parsing and checking of WebAssembly files, conversion from text format to binary format, and easy viewing of the binary representation of files. Its versatility makes it an essential part of the WebAssembly development process.