NAME

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

VERSION

Version 0.12

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 (wade at anomaly 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 Houston Perl Mongers

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