/usr/share/libxenomai-dev/ is in libxenomai-dev 2.6.2.1-2ubuntu2.
This file is owned by root:root, with mode 0o755.
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/usr/share/libxenomai-dev/examples/
/usr/share/libxenomai-dev/examples/Makefile
/usr/share/libxenomai-dev/examples/common/
/usr/share/libxenomai-dev/examples/common/Makefile
/usr/share/libxenomai-dev/examples/common/hw_direct_io.c
/usr/share/libxenomai-dev/examples/kernel/
/usr/share/libxenomai-dev/examples/kernel/skins/
/usr/share/libxenomai-dev/examples/kernel/skins/native/
/usr/share/libxenomai-dev/examples/kernel/skins/native/demos/
/usr/share/libxenomai-dev/examples/kernel/skins/native/demos/Makefile
/usr/share/libxenomai-dev/examples/kernel/skins/native/demos/latency.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/demos/satch.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/bound_task.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/cond_var.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/event_flags.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/kernel_task.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/local_heap.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/msg_queue.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/mutex.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/pipe.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/semaphore.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/shared_mem.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/sigxcpu.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/user_alarm.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/user_irq.c
/usr/share/libxenomai-dev/examples/kernel/skins/native/snippets/user_task.c
/usr/share/libxenomai-dev/examples/kernel/skins/posix/
/usr/share/libxenomai-dev/examples/kernel/skins/posix/demos/
/usr/share/libxenomai-dev/examples/kernel/skins/posix/demos/Kbuild
/usr/share/libxenomai-dev/examples/kernel/skins/posix/demos/Makefile
/usr/share/libxenomai-dev/examples/kernel/skins/posix/demos/accuracy.c
/usr/share/libxenomai-dev/examples/kernel/skins/psos+/
/usr/share/libxenomai-dev/examples/kernel/skins/psos+/demos/
/usr/share/libxenomai-dev/examples/kernel/skins/psos+/demos/Makefile
/usr/share/libxenomai-dev/examples/kernel/skins/psos+/demos/satch.c
/usr/share/libxenomai-dev/examples/kernel/skins/vxworks/
/usr/share/libxenomai-dev/examples/kernel/skins/vxworks/demos/
/usr/share/libxenomai-dev/examples/kernel/skins/vxworks/demos/Makefile
/usr/share/libxenomai-dev/examples/kernel/skins/vxworks/demos/satch.c
/usr/share/libxenomai-dev/examples/native/
/usr/share/libxenomai-dev/examples/native/Makefile
/usr/share/libxenomai-dev/examples/native/rtprint.c
/usr/share/libxenomai-dev/examples/native/sigdebug.c
/usr/share/libxenomai-dev/examples/native/trivial-periodic.c
/usr/share/libxenomai-dev/examples/posix/
/usr/share/libxenomai-dev/examples/posix/Makefile
/usr/share/libxenomai-dev/examples/posix/README
/usr/share/libxenomai-dev/examples/posix/satch.c
/usr/share/libxenomai-dev/examples/rtdm/
/usr/share/libxenomai-dev/examples/rtdm/driver-api/
/usr/share/libxenomai-dev/examples/rtdm/driver-api/Makefile
/usr/share/libxenomai-dev/examples/rtdm/driver-api/heartbeat.c
/usr/share/libxenomai-dev/examples/rtdm/driver-api/tut01-skeleton-app.c
/usr/share/libxenomai-dev/examples/rtdm/driver-api/tut01-skeleton-drv.c
/usr/share/libxenomai-dev/examples/rtdm/driver-api/tut02-skeleton-app.c
/usr/share/libxenomai-dev/examples/rtdm/driver-api/tut02-skeleton-drv.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/
/usr/share/libxenomai-dev/examples/rtdm/profiles/can/
/usr/share/libxenomai-dev/examples/rtdm/profiles/can/Makefile
/usr/share/libxenomai-dev/examples/rtdm/profiles/can/rtcan_rtt.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/Makefile
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/bufp-label.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/bufp-readwrite.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/iddp-label.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/iddp-sendrecv.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/xddp-echo.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/xddp-label.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/ipc/xddp-stream.c
/usr/share/libxenomai-dev/examples/rtdm/profiles/serial/
/usr/share/libxenomai-dev/examples/rtdm/profiles/serial/Makefile
/usr/share/libxenomai-dev/examples/rtdm/profiles/serial/cross-link.c