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8
votes
2answers
207 views

How can I find available network interfaces?

This is in regard to linux, but if anyone knows of a general *nix method that would be good. I booted a system yesterday with an ethernet cable plugged in. "NetworkManager" is not installed, so once ...
2
votes
2answers
32 views

Check if a drive has been Zeroed with xxd and uniq?

I'm looking for a way to check if the entire binary contents of a USB device are purely 0s. I'm trying this command: sudo xxd /dev/sdb | uniq but it has no output and just runs forever. I've ...
7
votes
1answer
44 views

How to find which serial port is in use?

The Question: I plugged in a device (i.e. GSM modem) through a serial port (a.k.a. RS-232), and I need to see with which file in /dev/ filesystem this device was tied up, to be able to communicate ...
0
votes
2answers
30 views

Can I change devices permissions with chmod?

Before read: I don't want to use any udev rule. I need to change (programmatically) the permissions of some device. But first in order to underestand what I have to do (in code) I want to make the ...
2
votes
0answers
33 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 ...
3
votes
1answer
29 views

How to get address of connected USB modem?

I just connected my N81 telephone as USB modem to Linux Mint 14. All works fine, just wondering how to find a full path to this device, something like /dev/tty*.
1
vote
1answer
28 views

Why does RTC device have 254,0 instead of 10,135 as Major,Minor numbers?

Why isn't /dev/rtc the well known "c 10 135" device that it's on x86, but a magic undocumented "c 254 0" device? Devices.txt lists this major number as LOCAL/EXPERIMENTAL USE. I'm working on a ...
2
votes
1answer
49 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 ...
0
votes
0answers
27 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>; ...
2
votes
0answers
19 views

What are the two values in < > in a device tree .dts file ?

Following is the code snippet in a device tree file: flash@0 { compatible = "n25q128"; reg = <0x0>; spi-max-frequency = <50000000>; ...
5
votes
1answer
102 views

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: ...
1
vote
0answers
49 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 ...
4
votes
1answer
135 views

Difference between /dev and /sys/class?

What is the difference between the device representation in /dev between the one in /sys/class? Is one prefered over the other? Is there something one offers and the other doesn't?
3
votes
1answer
88 views

Is there a way to change device names in /dev directory?

I wrote this rule for testing purpose: SUBSYSTEMS=="usb", ATTRS{manufacturer}=="Kingston", ATTRS{serial}=="001CC0EC34A2BB318709004B", ATTRS{idVendor}=="0951", ATTRS{idProduct}=="1642", ...
3
votes
2answers
105 views

Unable to find root device / sda partitions missing

I have installed Archlinux, and after that GRUB. I manually entered menu entries for both my Windows and Arch installation. GRUB has no problems booting, and can successfully load in Windows. It ...
1
vote
2answers
27 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 ...
15
votes
3answers
807 views

mv a file to /dev/null breaks dev/null

If I do: touch file; mv file /dev/null as root, /dev/null disappears. ls -lad /dev/null results in no such file or directory. This breaks applications which depend on /dev/null like SSH and can be ...
0
votes
1answer
24 views

Confusion about group `cdrom` in linux system

When I type command groups ubuntu, the output would we like, ubuntu : ubuntu adm dialout cdrom floppy audio dip video plugdev netdev admin I am interested in the cdrom group. What does the group ...
1
vote
0answers
23 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 ...
2
votes
1answer
86 views

Map physical USB device path to the Bus/Device number returned by lsusb

I need to get the title of the attached USB device. I can do that with lsusb. udev allows some substitutions when I write rules: say, we can use $kernel to get name of the device, or $devpath to get ...
6
votes
1answer
141 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 ...
1
vote
0answers
64 views

Fedora unable to detect USB or wireless networks? [closed]

I installed Fedora(Gnome) 19 on a Dell Inspiron with Intel i3 processor, and a factory built-in Windows 7 home premium OS. The installation process completed successfully. But now when I log into ...
0
votes
0answers
182 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 ...
1
vote
0answers
24 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.
0
votes
2answers
134 views

Allow non-root user to read/write /dev files

In my /dev folder, I would like the following files to be user readable and writable: /dev/ttyUSB0 /dev/gpib0 How do I do this without using chgrp? I can edit /etc/udev/rules.d but I do not know ...
1
vote
1answer
22 views

Disable emulated scroll wheel (EmulateWheel) for specific programs

Is it possible to disable evdev's EmulateWheel option when using specific programs? In my use case, I would like to be able to interact with the Acme text editor and with some VMs using my Thinkpad's ...
0
votes
0answers
89 views

Debian 7.3 - Nautilus doesn't show devices and partitions in left panel after changing partitions

Today I changed some partitions (moving, resizing) on my second hard drive and after restarting Debian I noticed that Nautilus doesn't show either partitions nor removable devices in left panel. In ...
1
vote
1answer
40 views

Why does the SELinux filesystem have it's own null device?

Looking through /sys/fs/selinux, I found this: # ls -l /sys/fs/selinux/null crw-rw-rw-. 1 root root 1, 3 Jan 24 02:47 /sys/fs/selinux/null Which is identical to /dev/null: # ls -l /dev/null ...
1
vote
1answer
55 views

Getting message “Error trying to open /dev/dvd exclusively” at the end of a DVD burning process when using growisofs

I am using Linux Fedora Core 4 (have to work with a legacy system) and trying to burn DVDs as a non-root user using the growisofs utility. I seem to be getting this error message at the end of the ...
1
vote
1answer
53 views

Permission of DVD device file not being retained when machine is rebooted

I am using Linux Fedora 4 and would like a non-root user to be able to write to DVDs using the DVD drive. I was able to do this by adding write access to the group of the device file /dev/scd0 and ...
1
vote
0answers
30 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 ...
2
votes
1answer
114 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 ...
3
votes
1answer
276 views

How creation of new USB device file in /dev/bus/usb/001/ directory work?

I noticed that every time I connect a USB device, a new device gets created in the /dev/bus/usb/001/ directory. Further on each reconnection of the same device, the "Device Number" and "ID" change. ...
3
votes
1answer
90 views

USB device to be detected at the “same” /dev point always?

In Linux (actually I'm with CentOS v6.5), whenever I plug in my USB Terminal/Character Device (some kind of USB Adapter) for the first time (after booted), it is detected at: /dev/ttyUSB0 But ...
3
votes
2answers
75 views

Is there a uniform way to discover information about devices?

UPD: Changed question title from manage devices to discover information about devices One of the frequent thing I do is look up info about devices on my systems. And I am constantly find myself ...
2
votes
1answer
47 views

What happens under the hood when some data is sent/received on an uart (or similar)?

I am trying to understand how computers work and I was thinking about peripherals. Here is what I understand so far but some parts are missing. Using an Arduino, I send some text every second (a then ...
3
votes
2answers
145 views

Why won't Linux let me play with /dev/dsp?

I'm working through a Linux textbook, and it's telling me about devices. It says that if I send the appropriate output to /dev/dsp, then it will play a sound. The example is cat file.wav > ...
0
votes
1answer
113 views

How to debug a device that changes from /dev/ttyUSB0 to /dev/ttyUSB1 at will?

I have a device plugged to a CentOS server that changes randomly from /dev/ttyUSB0 to /dev/ttyUSB1 and vice versa. The device I'm trying to connect is this one. How can I debug this?
1
vote
1answer
113 views

Difference between Device file and device drivers

I am beginner in device driver programming. I don't get the difference between device drivers and device files in Linux. Can anyone explain the difference?
0
votes
0answers
148 views

What are high level and low level device drivers

Recently I read that there are two types of drivers (at least for disk), one that are called high level drivers and another called low level device drivers. Can some one tell me what these are, and ...
1
vote
1answer
66 views

2 or more programs in same USB serial converter

Having a network of lets say 10 devices in RS-485, connected to the linux PC with a RS-485 to USB Converter. Already there is a C program interacting with the serial converter at /dev/ttyUSB0. My ...
1
vote
0answers
52 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 ...
1
vote
0answers
278 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 ...
4
votes
2answers
102 views

Can you identify transport via sysfs?

I'm writing a script, and I'm interested in being able to identify the transport class (fc - "fibre channel", scsi, iscsi, etc.) for a given block device. I can retrieve this information via ls -l ...
3
votes
2answers
118 views

Permissions to print directly to USB printer

I've a netbook with Linux. I've a usb/serial printer and I added the line chmod 666 /dev/tty* to rc.local and it prints straight after a reboot. When I close the lid of a netbook for a while and then ...
2
votes
0answers
69 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 ...
4
votes
3answers
1k views

what is stored in /dev/pts files and Can we open those?

I am curious to know that what is stored in /dev/pts/ files . Can we open those files ? According to my knowledge /dev/pts files are created for ssh or telnet session .
2
votes
1answer
487 views

Unable to use busybox implementation of hwclock

I have a buildroot generated kernel (3.6.11) and root file system running on an x86 device. It uses busybox and I am trying to set the BIOS hardware clock using hwclock. I get this error whenever I ...
0
votes
1answer
73 views

Random bug in Linux

Some time ago, I remember reading an article on randomization in computing, and how random you can actually get a system to be. The article came about, if I'm not mistaken, because of some seemingly ...
0
votes
2answers
97 views

ECC on a single block device

I have an SSD that I suspect failing silently now and then. I have run badblocks on it and it is clear that it is not bad sectors but might instead be some race condition in the electronics, in which ...