Skip to main content
Deno 2 is finally here 🎉️
Learn more
Module

std/wasi/snapshot_preview1.ts

Deno standard library
Go to Latest
The Standard Library has been moved to JSR. See the blog post for details.
import * as mod from "https://deno.land/std@0.190.0/wasi/snapshot_preview1.ts";

Provides an implementation of the WebAssembly System Interface.

Supported Syscalls

  • [x] args_get
  • [x] args_sizes_get
  • [x] environ_get
  • [x] environ_sizes_get
  • [x] clock_res_get
  • [x] clock_time_get
  • [ ] fd_advise
  • [ ] fd_allocate
  • [x] fd_close
  • [x] fd_datasync
  • [x] fd_fdstat_get
  • [ ] fd_fdstat_set_flags
  • [ ] fd_fdstat_set_rights
  • [x] fd_filestat_get
  • [x] fd_filestat_set_size
  • [x] fd_filestat_set_times
  • [x] fd_pread
  • [x] fd_prestat_get
  • [x] fd_prestat_dir_name
  • [x] fd_pwrite
  • [x] fd_read
  • [x] fd_readdir
  • [x] fd_renumber
  • [x] fd_seek
  • [x] fd_sync
  • [x] fd_tell
  • [x] fd_write
  • [x] path_create_directory
  • [x] path_filestat_get
  • [x] path_filestat_set_times
  • [x] path_link
  • [x] path_open
  • [x] path_readlink
  • [x] path_remove_directory
  • [x] path_rename
  • [x] path_symlink
  • [x] path_unlink_file
  • [x] poll_oneoff
  • [x] proc_exit
  • [ ] proc_raise
  • [x] sched_yield
  • [x] random_get
  • [ ] sock_recv
  • [ ] sock_send
  • [ ] sock_shutdown

Examples

Example 1

import Context from "https://deno.land/std@0.190.0/wasi/snapshot_preview1.ts";

const context = new Context({
  args: Deno.args,
  env: Deno.env.toObject(),
});

const binary = await Deno.readFile("path/to/your/module.wasm");
const module = await WebAssembly.compile(binary);
const instance = await WebAssembly.instantiate(module, {
  "wasi_snapshot_preview1": context.exports,
});

context.start(instance);

Classes

The Context class provides the environment required to run WebAssembly modules compiled to run with the WebAssembly System Interface.