Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.
Awesome Lists | Featured Topics | Projects
https://github.com/ilya33/udev-ffi

Perl bindings for libudev using ffi
https://github.com/ilya33/udev-ffi
libudev perl perl-bindings udev
Last synced: 2 days ago
JSON representation
Perl bindings for libudev using ffi
Host: GitHub
URL: https://github.com/ilya33/udev-ffi
Owner: Ilya33
License: other
Created: 2017-06-27T15:39:04.000Z (over 7 years ago)
Default Branch: main
Last Pushed: 2022-11-27T19:41:53.000Z (about 2 years ago)
Last Synced: 2025-01-06T03:12:01.334Z (2 days ago)
Topics: libudev, perl, perl-bindings, udev
Language: Perl
Homepage: https://metacpan.org/pod/Udev::FFI
Size: 165 KB
Stars: 7
Watchers: 2
Forks: 1
Open Issues: 0
Metadata Files:
- Readme: README.md
- Changelog: Changes
- License: LICENSE
Awesome Lists containing this project

README

        # NAME

Udev::FFI - Perl bindings for libudev using ffi.

# SYNOPSIS

    use Udev::FFI;

    use Udev::FFI::Devnum qw(:all); # <- import major, minor and makedev

    

    # get udev library version

    my $udev_version = Udev::FFI::udev_version() or

        die("Can't get udev library version: $@");

    

    

    # create Udev::FFI object

    my $udev = Udev::FFI->new() or

        die("Can't create Udev::FFI object: $@");

    

    

    # create udev monitor

    my $monitor = $udev->new_monitor() or

        die("Can't create udev monitor: $@");

    

    # add filter to monitor

    unless ($monitor->filter_by_subsystem_devtype('block')) {

        warn("Ouch!");

    }

    

    # start monitor

    if ($monitor->start()) {

        for (;;) {

            # poll devices, now insert or remove your block device

            my $device = $monitor->poll(); # blocking read

            my $action = $device->get_action();

    

            print("ACTION: $action\n");

            print('SYSNAME: '.$device->get_sysname()."\n");

            print('DEVNODE: '.$device->get_devnode()."\n");

    

            last; # for example

        }

    

        for (;;) {

            # poll devices, now insert or remove your block device

            if (defined(my $device = $monitor->poll(0))) { # non-blocking read like can_read in IO::Select

                my $action = $device->get_action();

    

                print("ACTION: $action\n");

                print('SYSNAME: '.$device->get_sysname()."\n");

                print('DEVNODE: '.$device->get_devnode()."\n");

            }

    

            sleep(1);

    

            last; # for example

        }

    }

    

    

    # enumerate devices

    my $enumerate = $udev->new_enumerate() or

        die("Can't create enumerate context: $@");

    

    $enumerate->add_match_subsystem('block');

    $enumerate->scan_devices();

    

    use Data::Dumper; # for dump values in $href and @a

    

    # scalar context

    my $href = $enumerate->get_list_entries();

    print(Dumper($href)."\n");

    

    # list context

    my @a = $enumerate->get_list_entries();

    print(Dumper(@a)."\n");

    

    if (@a) { # we got devices

        my $device = $udev->new_device_from_syspath($a[0]);

    

        if (defined($device)) {

            print('Device: '.$device->get_sysname()."\n");

    

            my $devnum = $device->get_devnum();

    

            # major, minor and makedev from Udev::FFI::Devnum

            my ($ma, $mi) = (major($devnum), minor($devnum));

    

            print("Major: $ma\n");

            print("Minor: $mi\n");

    

            $devnum = makedev($ma, $mi);

            print("Devnum: $devnum\n");

    

    

            # scalar context

            $href = $device->get_properties_list_entries();

            print(Dumper($href)."\n");

    

            # list context

            @a = $device->get_properties_list_entries();

            print(Dumper(@a)."\n");

        }

    }

# DESCRIPTION

Udev::FFI exposes OO interface to libudev.

# CONSTRUCTOR

- new()

    This is the constructor for a new Udev::FFI object.

    If the constructor fails undef will be returned and an error message will be in

    $@.

        my $udev = Udev::FFI->new() or

            die("Can't create Udev::FFI object: $@");

# METHODS

## new\_monitor( \[SOURCE\] )

Create new udev monitor and connect to a specified event source. Valid sources

identifiers are `'udev'` and `'kernel'`. This argument is optional and

defaults to `'udev'`.

Return new [Udev::FFI::Monitor](https://metacpan.org/pod/Udev%3A%3AFFI%3A%3AMonitor) object on success, undef with the error in $@

on failure.

    my $monitor = $udev->new_monitor() or

        die("Can't create udev monitor: $@");

## new\_enumerate()

Create an enumeration context to scan /sys.

Return new [Udev::FFI::Enumerate](https://metacpan.org/pod/Udev%3A%3AFFI%3A%3AEnumerate) object on success, undef with the error in $@

on failure.

    my $enumerate = $udev->new_enumerate() or

        die("Can't create enumerate context: $@");

## new\_device\_from\_syspath( SYSPATH )

Create new udev device, and fill in information from the sys device and the udev

database entry. The syspath is the absolute path to the device, including the

sys mount point.

Return new [Udev::FFI::Device](https://metacpan.org/pod/Udev%3A%3AFFI%3A%3ADevice) object or undef, if device does not exist.

    my $device0 = $udev->new_device_from_syspath('/sys/class/block/sda1');

    my $device1 = $udev->new_device_from_syspath('/sys/class/net/eth0');

    

    # ... some code

    my @devices = $enumerate->get_list_entries();

    for (@devices) {

        my $device = $udev->new_device_from_syspath($_);

    # ... some code

## new\_device\_from\_devnum( TYPE, DEVNUM )

Create new udev device, and fill in information from the sys device and the udev

database entry. The device is looked-up by its type and major/minor number.

Return new [Udev::FFI::Device](https://metacpan.org/pod/Udev%3A%3AFFI%3A%3ADevice) object or undef, if device does not exist.

    use Udev::FFI::Devnum qw(makedev);

    my $device0 = $udev->new_device_from_devnum('b', makedev(8, 1));

    my $device1 = $udev->new_device_from_devnum('c', makedev(189, 515));

## new\_device\_from\_subsystem\_sysname( SUBSYSTEM, SYSNAME )

Create new udev device, and fill in information from the sys device and the udev

database entry. The device is looked up by the subsystem and name string of the

device.

Return new [Udev::FFI::Device](https://metacpan.org/pod/Udev%3A%3AFFI%3A%3ADevice) object or undef, if device does not exist.

    my $device0 = $udev->new_device_from_subsystem_sysname('block', 'sda1');

    my $device1 = $udev->new_device_from_subsystem_sysname('net', 'lo');

    my $device2 = $udev->new_device_from_subsystem_sysname('mem', 'urandom');

## new\_device\_from\_device\_id( ID )

Create new udev device, and fill in information from the sys device and the udev

database entry. The device is looked-up by a special string:

> `'b8:1'` - block device major:minor

>

> `'c128:2'` - char device major:minor

>

> `'n2'` - network device ifindex

>

> `'+sound:card29'` - kernel driver core subsystem:device name

Return new [Udev::FFI::Device](https://metacpan.org/pod/Udev%3A%3AFFI%3A%3ADevice) object or undef, if device does not exist.

    my $device = $udev->new_device_from_device_id('b8:1');

## new\_device\_from\_environment()

Create new udev device, and fill in information from the current process

environment. This only works reliable if the process is called from a udev rule.

Return new [Udev::FFI::Device](https://metacpan.org/pod/Udev%3A%3AFFI%3A%3ADevice) object or undef, if device does not exist.

    # in udev.rules (for example)

    # SUBSYSTEM=="backlight", ACTION=="change", IMPORT{program}="/path/script.pl"

    

    # in script

    my $udev = Udev::FFI->new() or

        die("Can't create Udev::FFI object: $@");

    my $device = $udev->new_device_from_environment();

    if (defined($device)) {

        # $device is the device from the udev rule (backlight in this example)

        # work with $device

## Udev::FFI::udev\_version()

Return the version of the udev library. Because the udev library does not

provide a function to get the version number, this function runs the \`udevadm\`

utility.

Return undef with the error in $@ on failure. Also you can check $! value:

ENOENT (\`udevadm\` not found) or EACCES (permission denied).

    # simple

    my $udev_version = Udev::FFI::udev_version() or

        die("Can't get udev library version: $@");

    

    # or catch the error

    use Errno qw( :POSIX );

    my $udev_version = Udev::FFI::udev_version();

    unless (defined($udev_version)) {

        if ($!{ENOENT}) {

            # udevadm not found

        }

        elsif ($!{EACCES}) {

            # permission denied

        }

    

        die("Can't get udev library version: $@");

    }

# EXAMPLES

Examples are provided with the Udev::FFI distribution in the "examples"

directory.

# SEE ALSO

libudev

eudev

[FFI::Platypus](https://metacpan.org/pod/FFI%3A%3APlatypus) (Write Perl bindings to non-Perl libraries without C or XS)

[FFI::CheckLib](https://metacpan.org/pod/FFI%3A%3ACheckLib) (Check that a library is available for FFI)

# BUGS AND LIMITATIONS

Udev::FFI supports libudev 171 or newer. Older versions may work too, but it was

not tested.

Please report any bugs through the web interface at

[https://github.com/Ilya33/udev-ffi/issues](https://github.com/Ilya33/udev-ffi/issues). Patches are always welcome.

# AUTHOR

Ilya Pavlov, 

Contributors:

Mohammad S Anwar

# COPYRIGHT AND LICENSE

Copyright (C) 2017-2022 by Ilya Pavlov

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.