NAME

       Device::USB::Bus - Use libusb to access USB devices.

VERSION

       Version 0.38

SYNOPSIS

       This class encapsulates the USB bus structure and provides methods for retrieving data
       from it. This class is not meant to be used alone, it is part of the Device::USB package.

       Device:USB:LibUSB provides a Perl wrapper around the libusb library. This supports Perl
       code controlling and accessing USB devices.

           use Device::USB;

           my $usb = Device::USB->new();

           foreach my $bus ($usb->list_busses())
           {
               print $bus->dirname(), ":\n";
               foreach my $dev ($bus->devices())
               {
                   print "\t", $dev->filename(), "\n";
               }
           }

DESCRIPTION

       This module provides a Perl interface to the bus structures returned by the libusb
       library. This library supports a read-only interface to the data libusb returns about a
       USB bus.

FUNCTIONS

       dirname
           Return the directory name associated with this bus.

       location
           Return the location value associated with this bus.

       devices
           In array context, it returns a list of Device::USB::Device objects representing all of
           the devices on this bus. In scalar context, it returns a reference to that array.

       find_device_if
           Find a particular USB device based on the supplied predicate coderef. If more than one
           device would satisfy the predicate, the first one found is returned.

           pred
               the predicate used to select a device

           returns a device reference or undef if none was found.

       list_devices_if This method provides a flexible interface for finding devices. It takes a
       single coderef parameter that is used to test each discovered device. If the coderef
       returns a true value, the device is returned in the list of matching devices, otherwise it
       is not.
           pred
               coderef to test devices.

           For example,

               my @devices = $bus->list_devices_if(
                   sub { Device::USB::CLASS_HUB == $_->bDeviceClass() }
               );

           Returns all USB hubs found on this bus. The device to test is available to the coderef
           in the $_ variable for simplicity.

DIAGNOSTICS

       This is an explanation of the diagnostic and error messages this module can generate.

DEPENDENCIES

       This module depends on the Carp and Device::USB, as well as the strict and warnings
       pragmas. Obviously, libusb must be available since that is the entire reason for the
       module's existence.

AUTHOR

       G. Wade Johnson (gwadej at cpan dot org) Paul Archer (paul at paularcher dot org)

       Houston Perl Mongers Group

BUGS

       Please report any bugs or feature requests to "bug-device-usb@rt.cpan.org", or through the
       web interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Device::USB>.  I will be
       notified, and then you'll automatically be notified of progress on your bug as I make
       changes.

ACKNOWLEDGEMENTS

       Thanks go to various members of the Houston Perl Mongers group for input on the module.
       But thanks mostly go to Paul Archer who proposed the project and helped with the
       development.

       Thanks also go to Josep Monés Teixidor, Mike McCauley, and Tony Awtrey for spotting,
       reporting, and (sometimes) fixing bugs.

COPYRIGHT & LICENSE

       Copyright 2006-2013 Houston Perl Mongers

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.