Determine Usb Device File Path

Determine USB device file Path

So which device file is used for USB? How can i indentify it?

What you see behind /sys/ is mainly configuration/information about devices. /dev/bus/usb is what you are looking for. I think that the following article can help you

http://www.linuxjournal.com/article/7466?page=0,0

Is quite old, but still it can help you. (In the article they speak about /proc/bus/usb, today we have /dev/bus/usb)

Further more, could you explain to me the number 1-1:1.0? What does it mean?

The generic form is

X-Y.Z:A.B

Each field identify the connection point of your device. The first two field are mandatory:

• X is the USB bus of your motherboard where is connected the USB system.
• Y is the port in use on the bus system

So the USB device identified with the string 3-3 is the device connected on the port 3 of the bus 3.

If you connect an USB hub, you are extending the connection capability of a single USB port. The Linux kernel identify this situation by appending the Z field.

• Z is the port is use on an hub

So, the USB device identified with the string 1-2.5 is the device connected on the port 5 of the hub connected on the port 2 of the bus 1.

USB specification allow you to connect in cascade more then one USB hub, so the Linux kernel continue to append the port in use on the different hubs. So, the USB device identified with the string 1-2.1.1 is the device connected on the port 1 of the hub connected on the port 1 of the hub connected to the port 2 of the bus 1.

A fast way to retrieve these information is to read the kernel messages (if you can).

$ dmesg | grep usb
[... snip ...]
[ 2.047950] usb 4-1: new full-speed USB device number 2 using ohci_hcd
[ 2.202628] usb 4-1: New USB device found, idVendor=046d, idProduct=c318
[ 2.202638] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 2.202643] usb 4-1: Product: Logitech Illuminated Keyboard
[ 2.202648] usb 4-1: Manufacturer: Logitech
[... snip ...]

Then, the last two fields of the pattern (after colon) identify an internal section of an USB device :

• A is the configuration number of the device
• B is the interface number of a configuration

So, the string 4-1:1.1 means: the interface 1, on configuration 1 that is connected on the port 1 of the bus 4.

You can retrieve these information with the command lsusb.

Path of the USB devices which are connected to the machine?

Thumbs Up for Ardman's answer. Perfect.
To add a slight modification to it I would like to add modification to it where you can find the type of drive. It should cater your problem.

DriveInfo[] mydrives = DriveInfo.GetDrives();

        foreach (DriveInfo mydrive in mydrives)
        {
            if (mydrive.DriveType == DriveType.Removable)
            {
                Console.WriteLine("\nRemovable disk");
                Console.WriteLine("Drive: {0}", mydrive.Name);
                Console.WriteLine("Type: {0}", mydrive.DriveType);                    
            }
            else
            {
                Console.WriteLine("\nNon Removable disk\n");
                Console.WriteLine("Drive: {0}", mydrive.Name);
                Console.WriteLine("Type: {0}", mydrive.DriveType);                   
            }
        }

Or if you want to get the drive names specifically you can do like this too. Please mind that these were examples from web so that the particular authors should get the credit. What I have done is creating a complete program using those code snippets so that you can understand.

[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
    static extern bool GetVolumeInformation(string Volume, StringBuilder VolumeName, uint VolumeNameSize,out uint SerialNumber, out uint SerialNumberLength, out uint flags,StringBuilder fs, uint fs_size);

First write this function as it is. It uses the kernel32.dll to retreive the drive info.
Then in the main function you can simply add these codes (If it's a console application or if you have a GUI do appropriately.)

uint serialNum, serialNumLength, flags;
        StringBuilder volumename = new StringBuilder(256);
        StringBuilder fstype = new StringBuilder(256);
        bool ok = false;
        //Cursor.Current = Cursors.WaitCursor;
        foreach (string drives in Environment.GetLogicalDrives())
        {
            ok = GetVolumeInformation(drives, volumename, (uint)volumename.Capacity - 1, out serialNum,
                                   out serialNumLength, out flags, fstype, (uint)fstype.Capacity - 1);
            if (ok)
            {
                Console.WriteLine( "\n Volume Information of " + drives + "\n");
                Console.WriteLine( "\nSerialNumber of is..... " + serialNum.ToString() + " \n");
                if (volumename != null)
                {
                    Console.WriteLine("VolumeName is..... " + volumename.ToString() + " \n");
                }
                if (fstype != null)
                {
                    Console.WriteLine( "FileType is..... " + fstype.ToString() + " \n");
                }
            }
            ok = false;
        }

I guess this should be a complete answer for you.

How to get the path for a usb flash drive

If your application is running from the stick get your path like described here:

get path for my .exe

other option is to check the name of you device. Use the code described here:

Path of the USB devices which are connected to the machine?

How to detect the path for usb in QNX

Please follow this thread. This will solve your problem I hope.

Usb mass storage file system location on QNX

Find current connected USB storage path in C++

First you need to get removable drives:

void EnumUsbDrives() {
    DWORD drv = ::GetLogicalDrives();
    if (drv == 0) return;

    DWORD mask = 1;
    TCHAR szDrive[] = _TEXT("?:\\");

    for (uint_t i = 0; i < ('Z' - 'A' + 1); i++, mask <<= 1) {
        if (drv & mask) {
            szDrive[0] = (TCHAR)(_T('A') + i);
            if (::GetDriveType(szDrive) == DRIVE_REMOVABLE) {
                bool bUSB = IsDriveUSB(szDrive);
                if (bUSB) {
                    // Time do to something useful
                }
            }
        }
    }
}

Function IsDriveUSB is a bit more complicated. I have teared it from an in-house library; the function uses custom helper classes xregistry and xstring_nocase. Their purpose is pretty obvious, I believe you will have no trouble replacing it with other similar classes or API calls.

bool IsDriveUSB (LPCTSTR szDrive) throw() {
    TCHAR szLogicalDrive[] = _TEXT("\\\\.\\x:");
    szLogicalDrive[4] = szDrive[0];
    HANDLE hDrive = ::CreateFile(szLogicalDrive, FILE_READ_ATTRIBUTES, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
    if (hDrive == INVALID_HANDLE_VALUE) return false;       // Can't open drive so we have to assume the drive is fixed

    VOLUME_DISK_EXTENTS vde;
    DWORD dwBytesReturned = 0;
    BOOL br = ::DeviceIoControl(hDrive, IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS, NULL, 0, &vde, sizeof(vde), &dwBytesReturned, NULL);
    ::CloseHandle(hDrive);
    if (!br) return false;      // Can't get extents info so we have to assume the drive is fixed

    if (vde.NumberOfDiskExtents != 1) return false;
    ULONG uPhysDrive = vde.Extents[0].DiskNumber;
    TCHAR szPhysDrive[16];
    _stprintf(szPhysDrive, _TEXT("%u"), uPhysDrive);

    try {
        xregistry rk(HKEY_LOCAL_MACHINE, OS.Is64bit());
        rk.open(_TEXT("SYSTEM\\CurrentControlSet\\services\\Disk\\Enum"), KEY_QUERY_VALUE);
        if (!rk.value_exists(szPhysDrive)) return false;
        xstring_nocase strInterface = rk.get_string(szPhysDrive).substring(0, 7);
        return strInterface == _TEXT("USBSTOR");
    }
    catch (...) {
        return false;
    }
}

How to find my USB flash drive's path with PowerShell

I added a VolumeLabel("MyToolBox") to my usb Stick and put following line in the profile.ps1:

Get-DriveInfo | % { if( $_.VolumeLabel -eq "MyToolBox"){ Set-Location $_.Name; ./Startup.ps1}}

Get-DriveInfo comes from the module Pscx: http://pscx.codeplex.com/
You need to import this in you profile too...

The Startup.ps1 script is in the root of my usb stick and registers aliases on the stick for use in the session...

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