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Cyme

List system USB buses and devices. A modern cross-platform lsusb that attempts to maintain compatibility with, but also add new features. Profiles system USB buses and the devices on those buses, including full device descriptors.

As a developer of embedded devices, I use a USB list tool on a frequent basis and developed this to cater to what I believe are the short comings of lsusb: verbose dump is mostly too verbose, tree doesn't contain useful data on the whole, it barely works on non-Linux platforms and modern terminals support features that make glancing through the data easier.

The project started as a quick replacement for the barely working lsusb script and a Rust project to keep me up to date! Like most fun projects, it quickly experienced feature creep as I developed it into a cross-platform replacement for lsusb. It started as a macOS system_profiler parser, evolved to include a 'libusb' based profiler for reading full device descriptors and now defaults to a pure Rust profiler using nusb.

It's not perfect as it started out as a Rust refresher but I had a lot of fun developing it and hope others will find it useful and can contribute. Reading around the lsusb source code, USB-IF and general USB information was also a good knowledge builder.

The name comes from the technical term for the type of blossom on a Apple tree: cyme - it is Apple related and also looks like a USB device tree 😃🌸.

Features

• Compatible with lsusb using --lsusb argument. Supports all arguments including --verbose output - fully parsed device descriptors! Output is identical for use with no args (list), tree (excluding drivers on non-Linux) and should match for verbose (perhaps formatting differences).
• Default build is a native Rust profiler using nusb.
• Filters like lsusb but that also work when printing --tree. Adds --filter_name, --filter_serial, --filter_class and option to hide empty --hide-buses/--hide-hubs.
• Improved --tree mode; shows device, configurations, interfaces and endpoints as tree depending on level of --verbose.
• Controllable block data like lsd --blocks for device, bus, configurations, interfaces and endpoints. Use --more to see more by default.
• Modern terminal features with coloured output, utf-8 characters and icon look-up based device data. Can be turned off and customised. See --encoding (glyphs [default], utf8 and ascii), which can keep icons/tree within a certain encoding, --color (auto [default], always and never) and --icon (auto [default], always and never). Auto --icon will only show icons if all icons to be shown are supported by the --encoding.
• Can be used as a library too with system profiler module, USB descriptor modules and display module for printing amongst others.
• --json output that honours filters and --tree.
• --headers to show meta data only when asked and not take space otherwise.
• --mask_serials to either '*' or randomise serial string for sharing dumps with sensitive serial numbers.
• Auto-scaling to terminal width. Variable length strings such as descriptors will be truncated with a '...' to indicate this. Can be disabled with config option 'no-auto-width' and a fixed max defined with 'max-variable-string-len'.
• Targets for Linux, macOS and Windows.

Demo

Install

Requirements

For pre-compiled binaries, see the releases. Pre-compiled builds use native profiling backends and should require no extra dependencies.

From crates.io with a Rust tool-chain installed: cargo install cyme --git https://github.com/tuna-f1sh/cyme (from GitHub as crates.io pinned at the moment). To do it from within a local clone: cargo install --path ..

Package Managers

• Homebrew 'cyme' which will also install a man page, completions and the 'libusb' dependency:

brew install cyme

• Arch Linux official package

pacman -S cyme

• Debian packages as part of release - need a Debian maintainer for this.

More package managers to come/package distribution, please feel free to create a PR if you want to help out here.

Alias lsusb

If one wishes to create a macOS version of lsusb or just use this instead, create an alias one's environment with the --lsusb compatibility flag:

alias lsusb='cyme --lsusb'

Linux udev Information

Note

Only supported on Linux targets.

To obtain device and interface drivers being used on Linux like lsusb, one can use the --features udev feature when building - it's a default feature. The feature uses the Rust crate udevrs to obtain the information. To use the C FFI libudev library, use --no-default-features --features udevlib which will use the 'libudev' crate. Note that this will require 'libudev-dev' to be installed on the host machine.

To lookup USB IDs from the udev hwdb as well (like lsusb) use --features udev_hwdb. Without hwdb, cyme will use the 'usb-ids' crate, which is the same source as the hwdb binary data but the bundled hwdb may differ due to customisations or last update ('usb-ids' will be most up to date).

Profilers and Feature Flags

Native

Uses native Rust nusb and udevrs for profiling devices: sysfs (Linux), IOKit (macOS) and WinUSB.

It is the default profiler as of 2.0.0. Use --feature=native ('nusb' and 'udevrs' on Linux) or --feature=nusb to manually specify.

Libusb

Uses 'libusb' for profiling devices. Requires libusb 1.0.0 to be installed: brew install libusb, sudo apt install libusb-1.0-0-dev or one's package manager of choice.

Was the default feature before 2.0.0 for gathering verbose information. It is the profiler used by lsusb but there should be no difference in output between the two, since cyme uses control messages to gather the same information. If one wishes to use 'libusb', use --no-default-features and --feature=libusb or --feature=ffi for udevlib too.

Note

'libusb' does not profile buses on non-Linux systems (since it relies on root_hubs). On these platforms, cyme will generate generic bus information.

macOS system_profiler

Uses the macOS system_profiler SPUSBDataType command to profile devices.

Was the default feature before 2.0.0 for macOS systems to provide the base information; 'libusb' was used to open devices for verbose information. It is not used anymore if using the default native profiler but can be forced with --system-profiler - the native profiler uses the same IOKit backend but is much faster as it is not deserializing JSON. It also always captures bus numbers where system_profiler does not.

Tip

If wishing to use only macOS system_profiler and not obtain more verbose information, remove default features with cargo install --no-default-features cyme. There is not much to be gained by this considering that the default native profiler uses the same IOKit as a backend, can open devices to read descriptors (verbose mode) and is much faster.

Usage

Use cyme --help for basic usage or man ./doc/cyme.1. There are also autocompletions in './doc'.

Crate

For usage as a library for profiling system USB devices, the crate is 100% documented so look at docs.rs. The main useful modules for import are profiler, and usb.

There are also some examples in 'examples/', these can be run with cargo run --example filter_devices. It wasn't really written from the ground-up to be a crate but all the USB descriptors might be useful for high level USB profiling.

Config

cyme will check for a 'cyme.json' config file in:

• Linux: "$XDG_CONFIG_HOME/cyme or $HOME/.config/cyme"
• macOS: "$HOME/Library/Application Support/cyme"
• Windows: "{FOLDERID_RoamingAppData}/cyme"

One can also be supplied with --config. Copy or refer to './doc/cyme_example_config.json' for configurables. The file is essentially the default args; supplied args will override these. Use --debug to see where it is looking or if it's not loading.

Custom Icons and Colours

See './doc/cyme_example_config.json' for an example of how icons can be defined and also the docs. The config can exclude the "user"/"colours" keys if one wishes not to define any new icons/colours.

Icons are looked up in an order of User -> Default. For devices: Name -> VidPid -> VidPidMsb -> Vid -> UnknownVendor -> get_default_vidpid_icon, classes: ClassifierSubProtocol -> Classifier -> UndefinedClassifier -> get_default_classifier_icon. User supplied colours override all internal; if a key is missing, it will be None.

Icons not Showing/Boxes with Question Marks

Copied from lsd: For cyme to be able to display icons, the font has to include special font glyphs. This might not be the case for most fonts that you download. Thankfully, you can patch most fonts using NerdFont and add these icons. Or you can just download an already patched version of your favourite font from NerdFont font download page. Here is a guide on how to setup fonts on macOS and Android.

To check if the font you are using is setup correctly, try running the following snippet in a shell and see if that prints a folder icon. If it prints a box, or question mark or something else, then you might have some issues in how you setup the font or how your terminal emulator renders the font.

echo $'\uf115'

If one does not want icons, provide a config file with custom blocks not including the any 'icon*' blocks - see the example config. Alternatively, to only use standard UTF-8 characters supported by all fonts (no private use area) pass --encoding utf8 and --icon auto (default). The --icon auto will drop the icon blocks if the characters matched are not supported by the --encoding.

For no icons at all, use the hidden --no-icons or --icon never args.

Known Issues

• sudo is required to open and read Linux root_hub string descriptors and potentially all devices if the user does not have permissions. The program works fine without these however, as will use sysfs/hwdb/'usb-ids' like lsusb. Use debugging -z to see what devices failed to read. The env CYME_PRINT_NON_CRITICAL_PROFILER_STDERR can be used to print these to stderr. --lsusb --verbose will print a message to stderr always to match the 'lsusb' behaviour.
• Version major BCD Device difference between libusb and macOS system_profiler: If the major version is large, libusb seems to read a different value to macOS. I don't think it's a parsing error but open to ideas.
• Users cannot open special non-user devices on Apple buses (VHCI); T2 chip for example. These will still be listed with 'native' and system_profiler but not --force-libusb. They will not print verbose information however and log an error if --verbose is used/print if --lsusb.
• Tested with macOS 13 ->. I'm not sure when the -json flag was added to system_profiler; whether it exists on all macOS versions.