Hi,
How can I know what number descriptor is used by my usb device indicate via libusb_device_handle structure ? I can't find declaration of libusb_device_handle structure. I need this information to use poll() function where I need decripttion number of device. Thanks for help.

use lsusb


my computer output
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 06f2:0011 Emine Technology Co. KVM Switch Keyboard
Bus 003 Device 003: ID 046d:c016 Logitech, Inc. Optical Wheel Mouse
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 002: ID 0a5c:2101 Broadcom Corp. Bluetooth Controller

I hope this is enough information for you

there is another way to get extended information if you have the correct permissions.
somewhere in /proc/bus/usb are some ro files:

You can `cat' them and get extended information. Be careful please whilst in /proc.

Best I can do

Thanks for reply. But I must know number of file descriptor type of integer, assigned to interesting me usb device to use in code C/C++ with libusb library.

I know almost nothing about libusb. But do these links help?

link
link
link
link

http://www.beyondlogic.org/usbnutshe...iceDescriptors

I am not sure if you got your answer from the previous respondent but the above link is informative.

I don't know your system but on mine I can find all the information per USB device this way.

'cat /proc/bus/usb/devices' and then > to-a-file

It should look something like this. Of course you will need to interpret this information and I can't help you there. Let me know how you get on.


T: Bus=05 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2
B: Alloc= 0/900 us ( 0%), #Int= 0, #Iso= 0
D: Ver= 1.10 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0001 Rev= 2.06
S: Manufacturer=Linux 2.6.33.4-smp uhci_hcd
S: Product=UHCI Host Controller
S: SerialNumber=0000:00:1d.3
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 2 Ivl=255ms

T: Bus=05 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=0a5c ProdID=2101 Rev= 0.00
S: Manufacturer=Broadcom Corp
S: Product=BCM92045DG-Flash
C:* #Ifs= 4 Cfg#= 1 Atr=a0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=81(I) Atr=03(Int.) MxPS= 16 Ivl=1ms
E: Ad=82(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=83(I) Atr=01(Isoc) MxPS= 0 Ivl=1ms
E: Ad=03(O) Atr=01(Isoc) MxPS= 0 Ivl=1ms
I: If#= 1 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=83(I) Atr=01(Isoc) MxPS= 9 Ivl=1ms
E: Ad=03(O) Atr=01(Isoc) MxPS= 9 Ivl=1ms
I: If#= 1 Alt= 2 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=83(I) Atr=01(Isoc) MxPS= 17 Ivl=1ms
E: Ad=03(O) Atr=01(Isoc) MxPS= 17 Ivl=1ms
I: If#= 1 Alt= 3 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=83(I) Atr=01(Isoc) MxPS= 25 Ivl=1ms
E: Ad=03(O) Atr=01(Isoc) MxPS= 25 Ivl=1ms
I: If#= 1 Alt= 4 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=83(I) Atr=01(Isoc) MxPS= 33 Ivl=1ms
E: Ad=03(O) Atr=01(Isoc) MxPS= 33 Ivl=1ms
I: If#= 1 Alt= 5 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=83(I) Atr=01(Isoc) MxPS= 49 Ivl=1ms
E: Ad=03(O) Atr=01(Isoc) MxPS= 49 Ivl=1ms
I:* If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
E: Ad=84(I) Atr=02(Bulk) MxPS= 32 Ivl=0ms
E: Ad=04(O) Atr=02(Bulk) MxPS= 32 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 0 Cls=fe(app. ) Sub=01 Prot=00 Driver=(none)

T: Bus=04 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2
B: Alloc= 0/900 us ( 0%), #Int= 0, #Iso= 0
D: Ver= 1.10 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0001 Rev= 2.06
S: Manufacturer=Linux 2.6.33.4-smp uhci_hcd
S: Product=UHCI Host Controller
S: SerialNumber=0000:00:1d.2
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 2 Ivl=255ms

T: Bus=03 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2
B: Alloc= 41/900 us ( 5%), #Int= 3, #Iso= 0
D: Ver= 1.10 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0001 Rev= 2.06
S: Manufacturer=Linux 2.6.33.4-smp uhci_hcd
S: Product=UHCI Host Controller
S: SerialNumber=0000:00:1d.1
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 2 Ivl=255ms

T: Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=1.5 MxCh= 0
D: Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
P: Vendor=06f2 ProdID=0011 Rev= 1.00
S: Manufacturer=USB KVM Switch
S: Product=USB KVM Switch
C:* #Ifs= 2 Cfg#= 1 Atr=a0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=01 Driver=usbhid
E: Ad=81(I) Atr=03(Int.) MxPS= 8 Ivl=10ms
I:* If#= 1 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=usbhid
E: Ad=82(I) Atr=03(Int.) MxPS= 8 Ivl=10ms

T: Bus=03 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 3 Spd=1.5 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
P: Vendor=046d ProdID=c016 Rev= 3.40
S: Manufacturer=Logitech
S: Product=Optical USB Mouse
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=usbhid
E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=10ms

T: Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2
B: Alloc= 0/900 us ( 0%), #Int= 0, #Iso= 0
D: Ver= 1.10 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0001 Rev= 2.06
S: Manufacturer=Linux 2.6.33.4-smp uhci_hcd
S: Product=UHCI Host Controller
S: SerialNumber=0000:00:1d.0
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 2 Ivl=255ms

T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 8
B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0
D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1d6b ProdID=0002 Rev= 2.06
S: Manufacturer=Linux 2.6.33.4-smp ehci_hcd
S: Product=EHCI Host Controller
S: SerialNumber=0000:00:1d.7
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=256ms