devices refers to questions about the Unix/Linux device special files, normally these are under /dev. Do not use this tag for physical devices (for that use e.g. usb or pci).

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How do I find out the device node corresponding to my device in SuSE 8?

I'm forced to work with a bunch of point-of-sale systems running SuSE 8. They are my client's computers. We are stuck dealing with these old systems until they get to upgrade their whole fleet to SLE ...
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216 views

Remote Mouse netcat (/dev/input/mice)

I was playing around with nc and I'm discovering how powerful and versatile this tool is. I was wondering how the file /dev/input/mice works because when I do cat /dev/input/mice you see the output, ...
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102 views

Bad/strange USB device issue: failed to shutdown/restart

On a fresh Arch Linux installation with Intel i7 processor and an Nvidia graphics card, I noticed during boot log messages related to a usb device filled the screen before it reached the graphical ...
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202 views

How to rename devices for graphical output such as VGA0

On my Laptop the names of my graphical outputs change depending on what chip is activated in the BIOS. This leads to problems in some scripts where outputs such as VGA-0 or LVDS-0 are specified. So I ...
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253 views

How to route one video device to multiple programs

I'd like to direct the output of a single capture card (Hauppauge PVR-150) to two programs: VLC (for streaming on LAN) and MythTV for scheduled recording. I think it's possible to do this with the ...
3
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395 views

How to know the event by looking at /dev/input/by-id

I want to access the keyboard device driver. I usually accesses it by looking at /dev/input/by-name but the event provided by it gets changed every time I log in. After searchin on the Net, I found ...
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26 views

Enumerate valid values for mknod

I have access to an embedded device which has a bunch of block/char files under /dev. However, this is not a satisfying description of the hardware, because since the firmware is shared with small ...
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251 views

Why reading from and writing to framebuffer shows no effect ?

I read a very short description of how to make a Screenshot by making use of the file which represents the framebuffer /dev/fb0. in order to write the screen content: cat /dev/fb0 > file in ...
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52 views

Is there support for flattened device tree in Sparc 32 port of the Linux kernel?

We are trying to write a minimal bootloader for booting the linux kernel on a Sparc V8 processor simulator. From what I understand, the interface between the bootloader and kernel consists of a data ...
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75 views

PC speaker device missing

I've just connected a small internal PC speaker to my motherboard. The beep command is producing sounds correctly. The pcspkr is loaded but there is no /dev/pcsp, so I cannot send audio to it. How ...
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287 views

How do you determine the capabilities of a WebCam?

I have a collection of WebCam's lying around. Some of them are new, some go back a decade (gotta love not having to "upgrade" devices in Linux :). Somehow I've developed the impression that ...
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373 views

/dev/sda not appearing after secure erase

I decided to wipe my SSD with a secure erase before installing Arch Linux, since the Arch wiki said that it would improve performance. I followed the instructions listed on the wiki, but now when I ...
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200 views

Debian - cannot find cdrom

Having a jessie/sid debian box on kernel 3.13 (had same issue on kernel 3.10) First thing I notices was that k3b didn't find any optical drives. Then: The optical drives (dvd-writers) are found in ...
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583 views

Debian Wheezy USB2 ehci_hcd

I have a friend who decided to switch to Linux from Windows. I was helping her to get up and running as quickly as possible but we ran into a problem which I can't seem to solve. She uses Debian ...
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100 views

How to know when a device is ready

I have firewire mixing console and I wrote an udev rule which calls a script to set up the whole audio chain (alsa -> pulseaudio -> jackd -> firewire) as soon an the console is switched on. Now I ...
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203 views

Block Devices & Partitions

I partitioned a microSD card (mmcblk1) into two partitions mmcblk1p1 and mmcblk1p2. If use a dedicated card reader I am able to see the entire SD card and its partitions using various disk management ...
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228 views

Connected Android device - brings the network down?

I have dealt with sensitive development under Android, and have recently decided to switch to Linux now sit under (Mint 13 - KDE). But strangely, when the Android device is connected, my network goes ...
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63 views

Limiting write rate of a device

How does one go about limiting the write/read rate of a device, E.G., USB drive, SD card? Motivation behind this question is covered here (superuser.com).
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What are the differences between the current Linux kernel and the Unix SVR4 kernel in terms of device drivers+i/o and virtual files systems?

Yes I realize that Linux supports many more file systems and recognizes more devices than Unix SVR4. I'm interested in what the differences are in the abstraction on top of an actual file system, or ...
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16 views

iostat ( column svctm is not trusted any more ) what to use instead?

I'm running a Linux Server with "Oracle Linux Server release 6.5" which is pretty much the same as RedHat Version. I need to determine the latency on my disk devices. The man page of the iostat ...
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40 views

when running `udevadm test`: `no db file to read /run/udev/data/+gpio_sw:PA7: No such file or directory`

I am trying to write an udev rule that matches a GPIO Pin of my Orange Pi (the GPIOs use the gpio-sunxi kernel module). My ultimate goal is to let users who are member of a particular group access ...
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23 views

There is no /proc/bus/usb directory

I'm running a centos VM on ESXi. Does the /proc/bus/usb directory not show up until a USB device is connected? I just added a USB controller to the VM (it previously had non) and ran lsusb: $ ...
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96 views

how to get bus id of an usb device

I would like to bind/unbind my usb device - a wireless adapter. echo -n "1-1:1.0" > /sys/bus/usb/drivers/ub/unbind So to able to do that, I need the bus ID. lsusb prints out the following: Bus ...
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35 views

Can you create a read only encrypted partition that root cannot write to (or remount)?

I have an encrypted partition that I would like to be mounted as read only. The catch is that I do not want a root user to be able to remount the partition as read-write unless they have the ...
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72 views

udev: Passing parameters via $attr{key} does not work. How to solve it?

I want to enumerate my USB-UART bridges with my own script. The script shall be called with some attributes and return a new devfs node name. I tested the script on console: ./rc3e.py -d ...
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43 views

Disable embedded keyboard when in a tty

I've been lately working on a netbook. I like to connected an external keyboard and mouse to it whenever I can, and I put the keyboard over the embedded keyboard. When on X, I used xinput to disable ...
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48 views

Write shrunken .img file to device file

I have a backup image of a device file /dev/sda3 that I created using: dd if=/dev/sda3 of=~/sda3.img. The image is very large, so I have re-sized it to remove empty space. My question is can I ...
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149 views

Unable to find Documents on iPad device when mounted

It seems that this is a common problem, but there haven't been any satisfactory solutions posted yet, despite existing for years. Briefly, the problem is that when I mount my iPad in Linux Mint, I ...
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57 views

Help me to find my speakers and headphone paths (name of PCM device)

I am really confused trying to get my speakers and headphone device PCM names like a "hw:x,x" or something like that; cat /proc/asound/devices 2: [ 0] : control 3: [ 0- 0]: digital audio ...
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404 views

USB bar code scanner not working on Raspbian

My USB bar code scanner (SYMBOL LS2208) is recognized as a HID. hid-generic 0003:05E0:0600.000F: hiddev0,hidraw0: USB HID v1.10 Device [\xffffffef\xffffffbe\xffffffa9\xffffffbe\xffffffa9Symbol ...
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56 views

FreeBSD: Permanent nodes for usb devices

In FreeBSD, USB devices appear in /dev as (for example) /dev/ugen2.5, /dev/ugen2.6, etc... However, I noticed after a reboot sometimes these are pointing to different devices. Is there a way to lock ...
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86 views

Suse 10 - Same disk showed as IDE (hda) and SCSI (sda)

I have a strange problem with disk detection. I installed a Suse 10 and I see the same disk (scsi) showed as /dev/hda and /dev/sda. Here the fdisk output: sl0slmkmsd00:~ # fdisk -l /dev/hda Disk ...
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174 views

Bluetooth keyboard not showing up in /dev/input

I've just installed an Apple Wireless keyboard on a Debian system. I used this guide and only console tools — no X on that machine yet. The keyboard works fine. Now I want to remap a right Cmd key ...
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117 views

Pipe a device via USB or wlan

I have an Android phone and I want to use some of its onboard device from PC. To be more clear, there is a node in /dev/ and I want to have on PC a file (or named pipe which is accessable as a file) ...
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40 views

Detecting and categorizing device drivers in a running system

How can I obtain what device drivers are incorporated in a running kernel? More than this, how can I categorize these device drivers? For instance, this is a Linux kernel conceptual map, from ...
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212 views

Raspbian: USB storage device name changing after USB device power cycle

I'm running Raspbian 7.4 on a Raspberry PI that has two USB storage devices connected to it. This Raspberry PI will remain running during a power failure because it has console cable connected to it ...
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158 views

How/where are linux device capabilities / bitfields set?

I have a device that has this output in /proc/bus/input/devices: I: Bus=0003 Vendor=05b8 Product=3280 Version=0111 N: Name="PixArt USB Optical Mouse" P: Phys=usb-0000:00:1a.0-1.1/input0 S: ...
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21 views

character device file (rtai_shm) disappears under runlevel=5 in fedora9 (exists when runlevel=3)

I am trying to run Realtime (RTAI) on my Linux Fedora 9 machine. For that, it is needed to have a character device file, named rtai_shm, in /dev, that takes care of shared memory. I have made this ...
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64 views

Hotplug Device Driver Priority

Is it possible to have more than one driver for one purpose (eg. USB) included in the Linux kernel? If so, then how does the kernel decide which one to load?
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416 views

Editing a device tree to disable driver loading

Below is a section of device tree. ps7_ethernet_0: ps7-ethernet@e000b000 { #address-cells = <1>; #size-cells = <0>; clock-names = "ref_clk", "aper_clk"; clocks = ...
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200 views

Why is my embedded Linux unable to detect the sd device?

I have this ARM9 SAM9G25 embedded System, running a Linux 2.6.39 Kernel and a Busybox. I put the Images (of the bootloaders, and the linux+initramfs) on a SD so that in the end the system is booting ...
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33 views

Execute command when mouse is pluged/unpluged on GNU/Linux

Is it possible to have something like event handler for plugging unpluggig a mouse in Unix System? I want to have a script that will enable/disable touchpad but not only on startup (you can find ...
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167 views

Mount partition with truecrypt using the commandline

I'm trying to mount a encrypted HDD with truecrypt, but I cann't find the device. Where can I finde my HDD and what is the command to mount it in truecrypt? I'm using Raspbian on Raspberypi.
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110 views

Create a fake read only device like file with incrond

I need to generate UUID with uuidgen (not through any function call, but external command, because processes which will read the file cannot call any APIs or external commands directly). My idea is ...
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133 views

Which Unixes support cross-device filesystem links (in particular for rename)?

Just read the following on the FreeBSD man page for the rename syscall: ... [EXDEV] The link named by to and the file named by from are on different logical devices (file systems). Note that ...
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799 views

Check if Keyboard and Mouse are plugged in

Is there a way to detect if a keyboard and a mouse is plugged in (and working) in Linux? This will be embedded in a PXE setup, so I only have Kernel + Modules and Busybox available. Bonus question: ...
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14 views

How is Xserver able to tell which device is a mouse or a keyboard?

In these days we don't have to create a custom configuration that sets our devices up, at least when it comes to Xserver. But sometimes you want to change some default parameters. When you do it, you ...
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46 views

Linux doesn't recognize the SSD it's booting from!

I've extended a computer by a SSD and the BIOS recognizes it (and shows its name), but neither Ubuntu 14.4 nor Knoppix 7.6 show it in fdisk's output. Then I copied Fedora 23 WS Live to that SSD (on ...
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0answers
9 views

Devices for Analog I/O gone from /dev after reboot

I have a system using Centos 6.6 and another system using RHEL 6.6 on the same architecture that both need analog I/O drivers to communicate with sensors that will be attached to the device. Thus, I ...
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28 views

Tweaking the tripwire policy to stop checking for /dev/pts/x

Trying to streamline my Tripwire policy file, I see that I get a lot of chatter in every daily check report about ------------------------------------------------------------------------------ Rule ...