Files and directories

The worker client offers asynchronous POSIX-style operations. After await volume.ready, create a directory and file:

import { OpenFlags } from '@opfs-vfs/opfs-vfs';

await volume.mkdir('/notes', { recursive: true });
const fd = await volume.open('/notes/today.txt', OpenFlags.O_CREAT | OpenFlags.O_RDWR);
try {
  await volume.write(fd, new TextEncoder().encode('A garden on the moon.'), 0);
  const { buffer, read } = await volume.read(fd, 1024, 0);
  console.log(new TextDecoder().decode(buffer.subarray(0, read)));
} finally {
  await volume.close(fd);
}

await volume.rename('/notes/today.txt', '/notes/garden.txt');
console.log(await volume.readdir('/notes'));
await volume.flushVfs();

OpenFlags.O_TRUNC explicitly truncates an existing file. Without it, writing shorter content can leave the old trailing bytes in place. Use unlink to remove a file and rmdir to remove an empty directory. Await closeVfs() when the application is finished with the volume.

The just-bash adapter adds convenient readFile, writeFile, mkdir, mv, and rm methods. Its writeFile replaces the full file and creates missing parent directories.

When accepting uploaded files or generated paths, validate paths and set quotas. Render arbitrary HTML in a sandboxed iframe, never in the application DOM; the website demo shows this pattern.