tools: add a libinput list-kernel-devices tool

Same as libinput list-devices, but lists the available event nodes. This
effectively does the same as libinput record without arguments but it's
more obvious in what it is supposed to do and thus easier to point to.

Also, it uses pyudev instead of libevdev so it does not need to run as
root to discover devices.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

.gitlab-ci/libinput.spec.in

@@ -100,6 +100,7 @@ intended to be run by users.
 %files utils
 %{_libexecdir}/libinput/libinput-debug-gui
 %{_libexecdir}/libinput/libinput-debug-tablet
+%{_libexecdir}/libinput/libinput-list-kernel-devices
 %{_libexecdir}/libinput/libinput-measure
 %{_libexecdir}/libinput/libinput-measure-fuzz
 %{_libexecdir}/libinput/libinput-measure-touchpad-tap
@@ -115,6 +116,7 @@ intended to be run by users.
 %{_libexecdir}/libinput/libinput-analyze-touch-down-state
 %{_mandir}/man1/libinput-debug-gui.1*
 %{_mandir}/man1/libinput-debug-tablet.1*
+%{_mandir}/man1/libinput-list-kernel-devices.1*
 %{_mandir}/man1/libinput-measure.1*
 %{_mandir}/man1/libinput-measure-fuzz.1*
 %{_mandir}/man1/libinput-measure-touchpad-tap.1*

meson.build

@@ -507,6 +507,7 @@ src_python_tools = files(
 	      'tools/libinput-analyze-per-slot-delta.py',
 	      'tools/libinput-analyze-recording.py',
 	      'tools/libinput-analyze-touch-down-state.py',
+	      'tools/libinput-list-kernel-devices.py',
 	      'tools/libinput-measure-fuzz.py',
 	      'tools/libinput-measure-touchpad-size.py',
 	      'tools/libinput-measure-touchpad-tap.py',
@@ -961,6 +962,7 @@ src_man += files(
 	'tools/libinput-debug-events.man',
 	'tools/libinput-debug-tablet.man',
 	'tools/libinput-list-devices.man',
+	'tools/libinput-list-kernel-devices.man',
 	'tools/libinput-measure.man',
 	'tools/libinput-measure-fuzz.man',
 	'tools/libinput-measure-touchpad-size.man',

tools/libinput-list-kernel-devices.man

@@ -0,0 +1,25 @@
+.TH libinput-list-kernel-devices "1" "" "libinput @LIBINPUT_VERSION@" "libinput Manual"
+.SH NAME
+libinput\-list\-kernel\-devices \- list all kernel input devices
+.SH SYNOPSIS
+.B libinput list\-kernel\-devices [\-\-help]
+.SH DESCRIPTION
+.PP
+The
+.B "libinput list\-kernel\-devices"
+tool iterates through the list of available kernel devices and prints
+their device node and device name.
+.SH OPTIONS
+.TP 8
+.B \-\-help
+Print help
+.SH NOTES
+.PP
+A device may be available but not recognized by libinput. This may indicate
+a bug with the udev configuration. See the
+.B "libinput list\-devices"
+tools for the devices recognized by libinput.
+.SH LIBINPUT
+Part of the
+.B libinput(1)
+suite

tools/libinput-list-kernel-devices.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python3
+# vim: set expandtab shiftwidth=4:
+# -*- Mode: python; coding: utf-8; indent-tabs-mode: nil -*- */
+#
+# Copyright © 2018 Red Hat, Inc.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the 'Software'),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice (including the next
+# paragraph) shall be included in all copies or substantial portions of the
+# Software.
+#
+# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+# DEALINGS IN THE SOFTWARE.
+
+import argparse
+import sys
+
+try:
+    import pyudev
+except ModuleNotFoundError as e:
+    print("Error: {}".format(str(e)), file=sys.stderr)
+    print(
+        "One or more python modules are missing. Please install those "
+        "modules and re-run this tool."
+    )
+    sys.exit(1)
+
+
+def list_devices():
+    devices = {}
+    context = pyudev.Context()
+    for device in context.list_devices(subsystem="input"):
+        if (device.device_node or "").startswith("/dev/input/event"):
+            parent = device.parent
+            if parent is not None:
+                name = parent.properties["NAME"] or ""
+                # The udev name includes enclosing quotes
+                devices[device.device_node] = name[1:-1]
+
+    def versionsort(key):
+        return int(key[len("/dev/input/event") :])
+
+    for k in sorted(devices, key=versionsort):
+        print(f"{k}:\t{devices[k]}")
+
+
+def main():
+    parser = argparse.ArgumentParser(description="List kernel devices")
+    args = parser.parse_args()
+
+    list_devices()
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        print("Exited on user request")

tools/libinput.man

@@ -45,6 +45,9 @@ A commandline tool to debug tablet axis values
 .B libinput\-list\-devices(1)
 List all devices recognized by libinput
 .TP 8
+.B libinput\-list\-kernel-devices(1)
+List all kernel devices available on this system
+.TP 8
 .B libinput\-measure(1)
 Measure various properties of devices
 .TP 8