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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Is the directory that a file-system is mounted on (mount point) a device file of the file system's type?

A device file is an interface to the device driver of the device. When we mount a file system to a directory, is the directory considered a device file (of the file system's type)? If the ...
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Pegasus R6 Thunderbolt raid with CentOS 6.5

We have ourselves a rather expensive Mac Pegasus R6 external thunderbolt raid and a CentOS box that we would love to use it. On a Mac it's plug and play, however on our CentOS box it's not recognized ...
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3answers
165 views

How to inspect the contents of /dev/sdt?

I have what I hope is not a huge problem, but could end up being a very large problem. For some context, I mistakenly ran this command on my 27'' iMac: sudo dd if=ubuntu-rescue.img of=/dev/sdt ...
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1answer
123 views

Difference between /dev and /sys

Exactly what is the difference between devfs and sysfs? Both seem to maintain a list of hardwares attached to the system. Then why the need for 2 separate fs even arose? As far as I can get /sys ...
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1answer
381 views

Why does the UNIX system need so many [0-byte] drives at /dev/* [duplicate]

So I recently asked this question, which lead me to run this command: $ du -sk /dev/* Which outputs about 353 different entries that look like this: 0 /dev/sdt 0 /dev/stderr 0 /dev/stdin 0 ...
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2answers
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Mount an ISO virtually using /dev/sr0 device

I'm doing a study about how CD-ROM can be mounted virtually and all I could find out was mounting using loop devices. mount -o loop disk1.iso /mount-point This is fairly easy. I understand that ...
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1answer
2k views

Why is my Mac, upgraded from Mavericks to Yosemite, no longer giving VMware Fusion needed resources?

I have a Mac upgraded from Mavericks to Yosemite. When I tried to run VMware Fusion, I got an error stating: Could not open /dev/vmmon: No such file or directory. Please make sure that the kernel ...
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1answer
650 views

What is the difference between /dev/sda and /dev/hda? [duplicate]

Sometimes internal harddrives are available as /dev/sda (with subsequent media located in /dev/sdb etc), and other times available as /dev/hda. What is the difference between the two? Does it vary ...
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1answer
2k views

USB connect/disconnect notification

I use Linux Mint 13 MATE, and I'm trying to set up notifications when I plug/unplug devices. First of all, I found udev-notify package, but unfortunately it almost doesn't work for me: it works for ...
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Device nodes for an ATSC tuner not created

I'm trying to use an external tuner to tune to ATSC signals. But when I plug in the USB-Tuner I could see only frontend created. $ ls -ld /dev/dvb/adapter*{,/*} drwxr-xr-x 2 root root 60 Dec 5 ...
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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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1answer
144 views

chroot with unionfs-fuse, can't access /dev/*

I have created the a chroot jail in combination with unionfs-fuse so that I don't need to install another system inside it. However, the resulting system's /dev entries are not readable.This is ...
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2answers
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How can I create a direct 8khz audio pipe in Ubuntu?

I'm interested in creating musical programs like these: http://www.youtube.com/watch?v=GtQdIYUtAHg&feature=player_embedded Essentially these programs just generate sequences of integers, which ...
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1answer
64 views

Do all devices under Linux have a device node?

I know that each device on Linux is either a char or block or network device. Do all physical devices that exist on Linux have a device node under the /dev directory? I'm not talking here about ...
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1answer
25 views

Does network interface device have device inodes [duplicate]

Does network devices have device nodes because i have looked inside /dev directory and have not found any corresponding device node although it's up and running
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3answers
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Understanding /dev and its subdirs and files

$ ls -l /dev/stdin /dev/fd/0 lrwx------ 1 tim tim 64 2011-08-07 09:53 /dev/fd/0 -> /dev/pts/2 lrwxrwxrwx 1 root root 15 2011-08-06 08:14 /dev/stdin -> /proc/self/fd/0 $ ls -l /dev/pts/2 ...
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give group permissions to specific device

I have a panning web camera I built, (future robot arm). The camera pans via a web interface (cgi scripts and JS interface) which access an arduino. To enable sending of commands via the interface, I ...
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1answer
37 views

who is accessing /dev/video0

I have a streaming video feed set up with the motion package. something like this: https://www.youtube.com/watch?v=jGkHSU-UPLU works Great. What I want to know, is who is connecting to my streaming ...
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3answers
1k views

Are there alternatives to using `udev`?

While I understand the greatness of udev and appreciate the developers' effort, I was simply wondering if there is an alternative to it. For instance, I might imagine there should be a way to make ...
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1answer
362 views

Trying to read USB Audio Device, but /dev/hidraw0 is unavailable for reading

I'm trying to write a simple driver for my USB Sound Card (just for fun) on Xubuntu 14.04 -- for example, I want to have an opportunity to control volume on my laptop via this device. The problem is ...
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37 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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1answer
35 views

Can't Make a LDD for a Devkit8000

I'm trying to build a Linux Device Driver for a Devkit 8000. I'm getting the following errormessage: When I try to follow it's directions I get asked a bunch of yes/no questions I don't really ...
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2answers
49 views

How to run an application with certain group permissions?

I have a 3D printer, with which my PC can communicate through /dev/ttyACM0: crw-rw---- 1 root uucp 166, 0 16 nov 14:58 ttyACM0 The 3D printing application repetierHost requires read/write access ...
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1answer
110 views

create several /dev/xconsole files automatically upon boot

I understand from my previous question that the /dev/xconsole file can be created using mkfifo. On my system (Debian Wheezy), /dev/xconsole gets created automatically. I am wondering who creates it ...
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1answer
467 views

Is it possible to simulate/force/fake an USB device unplug and replug on Linux?

So I've got a strange problem that I've been running onto. I've got a bitcoin usb miner, Bitfury, and I'm using CGMiner to mine. When I start the application, as root, the USB device is not detected ...
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1answer
391 views

How to get device filename from lsusb output or by device path

Related question: USB connect/disconnect notification When the device is plugged/unplugged, I get instant notification, that's great. But to make it (almost) perfect, I also want to get device ...
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1answer
1k views

How to be notified when a USB device was plugged in?

My system has to auto-mount USB devices; how can I be notified when a USB device is plugged in? Where can I read more about this subject? I would like to handle this problem via C or a shell script. ...
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209 views

Why does a device show up as hidraw instead of hiddev?

I read the kernel documentation for hidraw and hiddev, and I understand the differences, but I am wondering how the kernel decides whether or not a device should show up as /dev/hidraw* or ...
3
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1answer
127 views

How to disable USB devices based on their vendor ID on GNU/Linux?

In that question someone wanted a blacklist for all USB devices, and then only allow specific devices. In this question, we want to accept all USB devices, but prevent the driver (e.g. cdc_acm) from ...
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2answers
4k views

How to grant non-root user access to device files

I have device file that appears in /dev when a specific board is plugged in. The read and write operations to it work just fine, but in order to open the device file the program needs to be executed ...
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0answers
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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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12answers
238k views

How do I find out what hard disks are in the system?

I need to know what hard disks are available, including ones that aren't mounted and possibly aren't formatted. I can't find them in dmesg or /var/log/messages (too much to scroll through). I'm hoping ...
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1answer
62 views

talk to modbus device

I currently have a minimal install of Red Hat 6.5 running, on the machine I need to talk to a modbus device. I am wondering what tools and drivers are needed on a linux machine to talk to a modbus ...
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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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1answer
4k views

How do I find out which process is using my V4L2 webcam?

I tried to run the following: $ vlc -I dummy v4l2:///dev/video0 --video-filter scene --no-audio --scene-path webcam.png --scene-prefix image_prefix --scene-format png vlc://quit --run-time=1 ...
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2answers
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What happens if I run fsck on /dev/sda instead of /dev/sda1?

When I have run fsck in the past I have always run it on what I thought was a filesystem partition, ie. fsck -yf /dev/sdaN, where N is the partition number on disk A. A friend of mine recently ran ...
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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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How can I mount the Logitech C270 in the zynq-7000 (with Linaro linux)?

I am doing camera control programming for a university project using zynq 7000. I want to mount the camera module that's for the Logitech C270 (like this ...
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1answer
115 views

create several /dev/xconsole files

I am using /dev/xconsole to send system logs from rsyslog. That works great, because I am don't have to store the logs on disk. I would like to have another similar file , i.e /dev/xconsole1 where I ...
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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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1answer
381 views

cannot create special file /dev/pts/0

When using midnight commander in console, I cannot "toggle" the window (using CTRL-o Not an xterm or Linux console; the panels cannot be toggled however, my $TERM is set to linux. After some ...
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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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3answers
655 views

Why doesn't xsetwacom work from udev?

I made a script to rotate my Wacom Bamboo tablet 180 degrees. It works fine when I execute it as myself (user) or root, but when started from udev (i.e. when plugging the tablet into a usb port) it ...
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unitek nec upd720200 not detected

I've decided to buy an USB3.0 controller on PCI for my debian machine. I did a short research and it appeared that NEC chips will be fine. I've bought Unitek NEC UPD720200 and I does not work: I ...
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1answer
61 views

Determine driver for network interface [duplicate]

I wanted to see which driver was associated with some of the network interfaces listed by ip link. My first thought was to find the network interfaces in /dev and look at the device major and minor ...
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1answer
111 views

USB 3G dongle internet keeps failing on Fedora 20 laptop

I use a 3G dongle for internet in my summerhouse, it has worked fine all summer, but since yesterday it has been losing connection, or something and I have to unplug it and insert it again for the ...
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1answer
1k views

can not create /dev/shm

I need to create /dev/shm on an embedded ARM system. From "Installed The Latest Changes to Current and......". I see that it can be created with mkdir /lib/udev/devices/shm, but I'm wondering what ...
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1answer
156 views

How do I send RTSP video to a program that reads from a character device?

I have an IP-CAM that streams video over RTSP and I want to detect bar codes from it with zbarcam (from Ubuntu's zbar-tools package). According zbarcam's manual, it expects to be given a video4linux ...
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3answers
93 views

Looking at the content of a character device's file [duplicate]

Why is it possible to look at the contents of a block device's file like /dev/sda using cat or a hex editor? Why can I not do the same for a character device like /dev/pts/3?
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1answer
496 views

udev Unable to Rename Network Device: Device or Resource Busy

I'm trying to use udev rules in order to give my network interfaces static, consistent names. However, it seems like there is some race condition happening preventing these rules from consistently ...