linux - Determine USB device file Path -

-

how can usb device file path correctly in linux. used command: find / -iname "usb" , got result below:

/dev/bus/usb /sys/bus/usb /sys/bus/usb/drivers/usb /sys/kernel/debug/usb

under /dev/bus/usb see:

001  002  003  004  005  006

but think aren't files need.

under /sys/bus/usb/devices/:

sh-3.2# ls /sys/bus/usb/devices/ 1-0:1.0  1-1:1.0  3-0:1.0  5-0:1.0  usb1     usb3     usb5 1-1      2-0:1.0  4-0:1.0  6-0:1.0  usb2     usb4     usb6

and under /sys/bus/scsi/devices/ when pluged usb see:

2:0:0:0      host0        host2        target2:0:0

and when removed usb see:

sh-3.2# ls host0

so device file used usb? how can indentify it? need make c program usb device file...

further more, explain me number 1-1:1.0? mean?

thank you.

so device file used usb? how can indentify it?

what see behind /sys/ configuration/information devices. /dev/bus/usb looking for. think following article can you

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

is quite old, still can you. (in article speak /proc/bus/usb, today have /dev/bus/usb)

further more, explain me number 1-1:1.0? mean?

the generic form is

x-y.z:a.b

each field identify connection point of device. first 2 field mandatory:

  • x usb bus of motherboard connected usb system.
  • y port in use on bus system

so usb device identified string 3-3 device connected on port 3 of bus 3.

if connect usb hub, extending connection capability of single usb port. linux kernel identify situation appending z field.

  • z port use on hub

so, usb device identified string 1-2.5 device connected on port 5 of hub connected on port 2 of bus 1.

usb specification allow connect in cascade more 1 usb hub, linux kernel continue append port in use on different hubs. so, usb device identified string 1-2.1.1 device connected on port 1 of hub connected on port 1 of hub connected port 2 of bus 1.

a fast way retrieve these information read kernel messages (if 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, last 2 fields of pattern (after colon) identify internal section of usb device :

  • a configuration number of device
  • b interface number of configuration

so, string 4-1:1.1 means: interface 1, on configuration 1 connected on port 1 of bus 4.

you can retrieve these information command lsusb.


Comments

Post a Comment

Popular posts from this blog

javascript - Chart.js (Radar Chart) different scaleLineColor for each scaleLine -

-
Image
i try , create radar chart using chart.js has various colours each scaleline, or coloured between scalelines. wondering if possible? from: to: i have working graph, though there doesn't seem method change individual scale lines. kind regards leigh you can extend radar chart type this, so chart.types.radar.extend({ name: "radaralt", initialize: function (data) { chart.types.radar.prototype.initialize.apply(this, arguments); var originalscaledraw = this.scale.draw; var ctx = this.chart.ctx; this.scale.draw = function () { var linewidth = this.linewidth; // bypasses line drawing in originalscaledraw this.linewidth = linewidth; originalscaledraw.apply(this, arguments); ctx.linewidth = this.linewidth; var scale = this; // draw chart.helpers.each(scale.ylabels, function (label, index) { // color of ...
Read more

apache - Error with PHP mail(): Multiple or malformed newlines found in additional_header -

-
suddenly have started receiving above error without changes having been made script. host 1and1 (i know...) the script still works fine on different server, , suspicion there must have been server config change has lead this, although hosts plead ignorance. there's no information on above error @ in google can find - have ideas? server running apache if helps. had similar problem. came out of blue. no php code changed. what changed: php upgraded 5.5.25-1 5.5.26. a security risk in php mail() function has been fixed , newlines in additional_headers allowed no more. because newlines mean: starts email message (and surely don't want inject newlines through headers followed evil message). what have worked fine, e.g. having newlines after headers or passing whole message additional_headers , function no more. solution : sanitize headers. no multiple newlines in additional_headers argument. these count "multiple or malformed newlines":...
Read more

java - Android – MapFragment overlay button shadow, just like MyLocation button -

-
Image
i'm struggling add shadow custom overlay button on google map. goal make custom button google's mylocation button. here's how app looks now: layout.xml <relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:map="http://schemas.android.com/apk/res-auto" android:layout_height="match_parent" android:layout_width="match_parent" style="@style/apptheme"> <fragment android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/map" tools:context=".mapsactivity" android:name="com.google.android.gms.maps.supportmapfragment" android:layout_alignparentend="true" android:layout_alignparentstart="true" android:layout_alignparentbottom="true" ...
Read more