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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Creating eth0 with consistent network device naming

From my understanding, Arch Linux uses Consistent Network Device Naming where the network devices are no longer named eth0, eth1, etc. I use the proprietary MATLAB software which requires a device ...
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1answer
24 views

Pushing changes to driver repos

My understanding of dkms is that its a way to dynamically manage all connected/disconnected device drivers on a Linux system. If that's correct, then I have to imagine that it allows you to configure ...
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2answers
33 views

Creating a device similar to /dev/random from a script

I am writing a program for which I will create a script to generate test data in a specific format. How can I create a /dev/myprogram device that would work similar to /dev/random (preferably in ...
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5answers
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Why does “cat ttyUSB0” not produce output?

I connected an infrared receiver to a USB port ... (the last line of dmesg tells device file) $ dmesg [10496.596063] usb 7-2: new full-speed USB device number 2 using uhci_hcd [10496.751112] usb 7-2: ...
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4answers
710 views

Trouble with understanding the concept of mounting

Having read both What is meant by mounting a device in Linux? and understanding "mount" as a concept in the OS, I have a problem where it is stated that All accessible storage must have ...
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9answers
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Why do we need to mount on Linux?

I understand what mounting is in Linux, and I understand device files. However I do not understand WHY we need to mount. For example, as explained in the accepted answer of this question, using this ...
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3answers
15k views

What is stored in /dev/pts files and can we open them?

According to my knowledge, /dev/pts files are created for ssh or telnet sessions.
1
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1answer
53 views

Why does tapping a TTY device only capture every other character?

So, I came across the ttyname function (unistd.h) and had to test it out. #include <unistd.h> #include <stdio.h> int main(void) { printf("%s\n", ttyname(0)); return 0; } On my ...
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0answers
87 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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2answers
26 views

how to know which device was open

is there any shell command, can let me know, current open device or device already in operation. For example, I use minicom to open a device /dev/ttyUSB0 or /dev/ttyS0, after I use program open this ...
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0answers
263 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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2answers
259 views

What is a device tree and a device tree blob?

What exactly is a device tree, and a device tree blob? Where can I get its source code for a particular linux version? I found such name while running linux on xilinx chips (having ARM 9), for ...
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1answer
24 views

Does programmer use device files as interface to device drivers in their programs?

In Linux shell, a user can access a device driver, via its device file as the interface. When a Linux C programmer want to access a driver in his C program, does he also access the driver, via its ...
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1answer
266 views

How can I set device rw permissions permanently on Raspbian?

I'm using the Raspbian (a distribution made for Raspberry Pi, which is based on Debian). I have some scripts that use i2c. Normally only root has read and write permissions for i2c. I'm using this ...
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0answers
108 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 ...
1
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1answer
25 views

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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0answers
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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
189 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
140 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 ...
6
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1answer
393 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
1k views

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
1k 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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0answers
19 views

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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0answers
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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
183 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
1k views

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 ...
4
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1answer
65 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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0answers
19 views

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 ...
2
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1answer
39 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
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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
411 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 ...
2
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0answers
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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 ...
0
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1answer
39 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 ...
4
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2answers
54 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 ...
2
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1answer
127 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 ...
2
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1answer
489 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 ...
2
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1answer
455 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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0answers
232 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
votes
1answer
139 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 ...
5
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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 ...
2
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0answers
35 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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12answers
248k 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
66 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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0answers
74 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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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
1k views

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 ...