README

libusb-compat-0.1
=================

A compatibility layer allowing applications written for libusb-0.1 to work
with libusb-1.0. libusb-compat-0.1 attempts to look, feel, smell and walk
like libusb-0.1.

Do not attempt to install libusb-0.1 and libusb-compat-0.1 on the same system.

Known quirks/differences from libusb-0.1:
 1. usb_resetep(), a previously deprecated function, is implemented as
    equivalent to calling usb_clear_halt().
 2. libusb-0.1 allowed you to open a device which you did not have permission
    to do anything useful with (all I/O requests would immediately fail).
    libusb-compat-0.1 does not allow you to open such devices. You can still
    read descriptor info without opening a device.
 3. usb_device's "num_children" attribute is hardcoded to 0, and "children"
    is hardcoded to NULL. Do you need this information in your software? Let
    us know on the mailing list, and we'll add it.
 4. Some libusb-0.1 users may have implemented I/O cancellation by running
    transfers in their own threads and simply killing the thread when they
    don't want to do the transfer any more. This is bad programming practice
    for obvious reasons, and this lack of functionality was one of the primary
    drivers for libusb-1.0 development. With libusb-1.0 or libusb-compat-0.1
    backed by libusb-1.0, forcefully killing threads in this way is likely
    to cause all libusb I/O to halt. Instead, port your application to use
    libusb-1.0's asynchronous transfer API, which supports transfer
    cancellation.
 5. Error codes returned on certain events may not exactly match the error
    codes returned by libusb-0.1. Patches accepted to bring us closer to the
    behaviour of libusb-0.1 on Linux.
 6. The internal structure of usb_dev_handle is different from libusb-0.1. Of
    course, since this is a purely internal structure, that shouldn't cause
    any problems. In reality, some libusb-0.1 users make assumptions about what
    is inside (bad programming practice) and those assumptions are no longer
    true, resulting in broken software.

libusb homepage:
http://libusb.org/

Use the mailing list for questions, comments, etc:
https://sourceforge.net/mailarchive/forum.php?forum_name=libusb-devel

- Peter Stuge <peter@stuge.se>
(use the mailing list rather than mailing developers directly)