English 中文(简体)
Getting mount point when a USB device is inserted Mac OS X and linux
原标题:

I am trying to develop a program in Mac OS and Linux which lists the files and folders in USB drive. I need to get the some events when USB device is connected and removed. I know that in Mac OS X I can use IOKit. But I do n t know how to get the mount point where the device is mounted. Can I get it using IOkit? Is there any cross platform solution for Linux and Mac?

问题回答

No, there isn t. Under Linux you may use HAL or DeviceKit-disks D-Bus interfaces. Note those are optional components and may be absent. HAL is older and DeviceKit-disks is newer implementations, with DK-d replacing HAL.

The approach I used for getting the available mount-points (with Java) pipes the output of the "system_profiler SPUSBDataType -xml" command to dd-plist processor. It subsequently recurses over the USB hierarchy, matching those having a "volumes" key. For each item in this array, retrieve the "mount_point" key to retrieve the location where it is mounted. See the code sample below:

/*
Copyright © 2014 Edwin de Jong. All Rights Reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY [LICENSOR] "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/
package nl.topicuszorg.laos.util.osx;

import java.io.IOException;
import java.io.InputStream;
import java.text.ParseException;
import java.util.List;
import java.util.Map;

import javax.xml.parsers.ParserConfigurationException;

import nl.topicuszorg.laos.model.response.MountState;
import nl.topicuszorg.laos.model.response.MountedDevice;

import org.xml.sax.SAXException;

import com.dd.plist.NSArray;
import com.dd.plist.NSDictionary;
import com.dd.plist.NSObject;
import com.dd.plist.NSString;
import com.dd.plist.PropertyListFormatException;
import com.dd.plist.PropertyListParser;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableList.Builder;

public class USBHelpers
{
  private static final String SYSTEM_PROFILER_COMMAND = "/usr/sbin/system_profiler";

  private static final String SPUSB_DATA_TYPE = "SPUSBDataType";

  private interface SpUSBDataTypeIdentifiers
  {
    String ITEMS = "_items";

    String VOLUMES = "volumes";

    String VENDOR_ID = "vendor_id";

    String MOUNT_POINT = "mount_point";

    String NAME = "_name";
  }

  public static List<MountedDevice> findMountedDevicesOsX() throws IOException, PropertyListFormatException,
    ParseException, ParserConfigurationException, SAXException
  {
    final Process process = new ProcessBuilder(SYSTEM_PROFILER_COMMAND, SPUSB_DATA_TYPE, "-xml")
      .start();
    return findMountedDevicesInConfiguration(process.getInputStream());
  }

  private static List<MountedDevice> findMountedDevicesInConfiguration(final InputStream processInputStream)
    throws IOException, PropertyListFormatException, ParseException, ParserConfigurationException, SAXException
  {
    // Root is an array, the USB devices are hierarchical in _items (and eg. _items(0)._items)
    final NSArray array = (NSArray) (PropertyListParser.parse(processInputStream));
    final NSDictionary dict = (NSDictionary) array.objectAtIndex(0);
    final NSArray itemsArray = (NSArray) dict.get(SpUSBDataTypeIdentifiers.ITEMS);
    return recurseUSBDevices(itemsArray);
  }

  public static List<MountedDevice> recurseUSBDevices(NSArray items)
  {
    final Builder<MountedDevice> builder = ImmutableList.builder();
    for (NSObject item : items.getArray())
    {
      builder.addAll(recurseUSBDevice((NSDictionary) item));
    }

    return builder.build();
  }

  private static List<MountedDevice> recurseUSBDevice(final NSDictionary dict)
  {
    final Builder<MountedDevice> builder = ImmutableList.builder();
    for (final Map.Entry<String, NSObject> entry : dict.entrySet())
    {
      if (entry.getKey().equals(SpUSBDataTypeIdentifiers.ITEMS))
      {
        // The USB device is a hub
        builder.addAll(recurseUSBDevices((NSArray) entry.getValue()));
      }
      if (entry.getKey().equals(SpUSBDataTypeIdentifiers.VOLUMES))
      {
        // This is a mountable device. We need to get the volumes, and for each volume, return it.
        List<MountedDevice> mountedDeviceOpt = parseVolumes((NSArray) (entry.getValue()));
        for (MountedDevice mountedDevice : mountedDeviceOpt)
        {
          mountedDevice.setVendorId(((NSString) dict.get(SpUSBDataTypeIdentifiers.VENDOR_ID)).toString());
          builder.add(mountedDevice);
        }
      }
    }
    return builder.build();
  }

  private static List<MountedDevice> parseVolumes(final NSArray nsArray)
  {
    final Builder<MountedDevice> builder = ImmutableList.builder();
    for (final NSObject item : nsArray.getArray())
    {
      builder.add(parseVolume((NSDictionary) item));
    }
    return builder.build();

  }

  private static MountedDevice parseVolume(final NSDictionary item)
  {
    final String mountPoint = ((NSString) item.get(SpUSBDataTypeIdentifiers.MOUNT_POINT)).toString();
    final String name = ((NSString) item.get(SpUSBDataTypeIdentifiers.NAME)).toString();
    return new MountedDevice(mountPoint, name, null, null, MountState.MOUNTED);
  }

}




相关问题
Designing Web Interface for Embedded System

OS : Linux. I m trying to find possible ways to implement web interface for my embedded system. Currently there is a shell (text based) and a small set of commands are implemented to query the ...

How bind socket to device in windows?

I have same network cards in computer. All cards has identical IP. I need to bind socket to specific card. In linux I can use flag SO_BINDTODEVICE. How I can do this in windows. P.S. This needed for ...

Choose between multiple devices in XCode

I ve 2 devices (iPhone + iPod) connected to my Mac and both are available as developper devices in XCode. How can I choose which one to use for testing purpose and switch from one to the other when I ...

Simulate a faulty block device with read errors?

I m looking for an easier way to test my application against faulty block devices that generate i/o read errors when certain blocks are read. Trying to use a physical hard drive with known bad blocks ...

Is there software or code to alter USB power output

I had a look at this and this but no one sounded particularly sure of their ideas and I m kind of after a different thing anyway. I want to hook my usb power cables (red and black) up to my phone so I ...

热门标签