win_ioctl

Node.js add-on to allow calls of DeviceIoControl() on Windows machines

Installation

Install with npm:

$ npm install win_ioctl

API

win_ioctl(fd, code, input, outBufSize, cb)

Parameters

• fd: Integer file descriptor, must be open.
• code: Integer Device specific control code.
• input optional: Buffer Input data to send to device
• outBufSize optional: Integer Size of output buffer to allocate
• cb optional: Function Callback to be called after operation finish Signature is function (err, data) where err is instance of Error and data is Buffer

Returns: Buffer Allocated buffer of outBufSize size with data returned by device or undefined if cb is passed

Throws: Throws if cb is unset

Examples

Get compression status of file

const comp_names =
{
    0: 'COMPRESSION_FORMAT_NONE',
    1: 'COMPRESSION_FORMAT_DEFAULT',
    2: 'COMPRESSION_FORMAT_LZNT1',
};

let comp = win_ioctl(fd, FSCTL_GET_COMPRESSION, undefined, 2);
console.log('Compression: ' + comp_names[comp.readUInt16LE(0)]);

Async variant

const comp_names =
{
    0: 'COMPRESSION_FORMAT_NONE',
    1: 'COMPRESSION_FORMAT_DEFAULT',
    2: 'COMPRESSION_FORMAT_LZNT1',
};

win_ioctl(fd, FSCTL_GET_COMPRESSION, undefined, 2, (err, d) =>
    console.log(err ? err : 'Compression: ' + comp_names[d.readUInt16LE(0)]));

Read variable-length data in case of ERR_MORE_DATA driver return:

win_ioctl(fd, FSCTL_FILESYSTEM_GET_STATISTICS, undefined, SIZE_OF_FILESYSTEM_STATISTICS, (err, data) =>
{
    if (err)
    {
        if (err.code == 'ERANGE' && data)
        {
            let structSize = data.readUInt32LE(4), fullSize = os.cpus().length * structSize;
            let fullData = win_ioctl(fd, FSCTL_FILESYSTEM_GET_STATISTICS, undefined, fullSize);
            console.log('File has been read '+fullData.readUInt32LE(8)+' times');
        } else
            console.log('Error: '+err.message);
    } else
        console.log('Error: unexpected success of first request with small buffer!');
});