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1

It turns out that this problem was specific to RaspberryPi, since the /dev/ttyAMA0 serial port that's linked to the hardware GPIO pins by default is initialized for virtual console access. I had to remove any reference to /dev/ttyAMA0 in /boot/cmdline.txt, reboot, and the /dev/ttyAMA0 now was with proper group permissions (read+write), however the group ...


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You could also try to use the device by the USB address (i.e. controller/hub and device number), like so: ls -l /dev/bus/usb/0??/0?? You can find out the device number by using the lsusb command (try using it as root if you do not get all the information you need, albeit it usually tends to give you rather a lot of info), or use udevadm info ...


1

I had a similar problem with a USB device using the pl2303 driver. Every now and again /dev/ttyUSB0 would vanish and /dev/ttyUSB1 would appear in its place. I solved it by running a cronjob every 15 minutes that did the following: if [ ! -c /dev/ttyUSB0 ] then echo `date` Device missing echo `date` Stopping zmconcopy `/usr/sbin/rczmconcopy stop ...


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Device files on Unix systems in general are just one way for user programs to access device drivers; there isn't a one-to-one mapping from devices files to physical hardware, and not all hardware has a device file (or even a device driver). The kernel itself doesn't use device files to interact with hardware. As pointed out by lcd047, network cards don't ...


0

For me (Debian sid/stretch), the udev $id attribute is empty when I plug in my USB device. It is $kernel that contains the necessary string to pass to USBHID's unbind. Here are the udev rules that I'm using: SUBSYSTEM=="usb", ATTRS{idVendor}=="0000", ATTRS{idProduct}=="0000", MODE="0660", GROUP="plugdev" ATTRS{idVendor}=="0000", ATTRS{idProduct}=="0000", ...


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fuser /dev/audio (or whatever devices and paths there are to your OS's sound device(s))


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I think that just checking if the value of /sys/class/net/<interface>/type is 1 (ARPHRD_ETHER) should be enough to understand if the device is a physical one. http://lxr.linux.no/linux+v3.0/include/linux/if_arp.h#L30


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Traditionally, unix systems have a script to create entries in /dev, called MAKEDEV and located in /dev. This script is often present on Linux, but may be absent on embedded devices where the designer assumed that all devices would be present, or on systems running udev where devices entries are normally created automatically. Note that MAKEDEV usually ...


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A workaround is to check the current bus/device configuration for your device as it'll be portable too and I think the usb host controller allocates these numbers dynamically, here's using awk you can get the current bus and device lsusb | grep "045e:00cb" | tr -d ':'| awk '{print "Bus="$2 " Device="$4}' You use $2 and $4 in anyway for example : ls ...


1

You can manually create the /dev entry using mknod /dev/ttyUSBn c 188 n Parameters: mknod is widely known tool to create /dev entries /dev/ttyUSBn: device name c : char device 188 : major device number n : minor device number,ttyUSB0, ttyUSB1, etc. But the device should be created automatically according to the udev rules


6

You cannot mmap() /dev/random or /dev/urandom. Nor can you seek() them for that matter. And as a general rule, you cannot mmap() unseekable things. Pipes are another example of things you cannot mmap() because they are not seekable. /dev/random and /dev/urandom are fundamentally stream-based, sequential access, devices. They produce bytes on demand when you ...


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As per RedHat documentation you can't reduce mounted filesystem. Check here for detailed document


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To answer your question about out-of-the-box automounting: I wouldn't expect mounting to happen out-of-the-box without reference to your desktop environment (gnome). Debian 6 isn't that old. I've used LXDE from it or equivalent. The uselessly generic answer is that all desktop environments (DEs) will include a filemanager. Your filemanager will let you ...


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Since posting I've continued digging and found several resources surrounding the issue and though I'd note them here. on OSX if you have Xcode installed there are utilities that are useful in the /Dev*/App*/Util*/ directory... specifically USBProber.app and IORegistryExplorer.app in USBProper there is a check box for "Probe suspended devices". once checked ...



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