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我正在运行 Ubuntu 12.04 编译具有以下代码的 c++ 文件

#include <iostream>
#include <libusb-1.0/libusb.h>

using namespace std;

int main(){
    //pointer to pointer of device used to retrieve a list of devices
    libusb_device **devs;
    libusb_device_handle *dev_handle; //a device handle
    libusb_context *ctx = NULL; //A LIBUSB session
    int r;// for return values
    ssize_t cnt; //holding number of devices in list
    r = libusb_init(&ctx); // initialize the library for the session we just declared

    if(r < 0){
        cout <<"init error "<<r<< endl;
        return 1;
    }

    libusb_set_debug(ctx, 3); // set verbosity level to 3, as suggested in the documentation
    cnt = libusb_get_device_list(ctx, &devs); //get the list of devices

    if (cnt < 0) {
        cout <<"Get Device Error "<< endl; // there was an error
        return 1;
    }

    cout << cnt <<" Device in list " << endl;
    //dev_handle = libusb_open_device_with_vid_pid(ctx, 0951, 1689); // these are vendor id and product id   //simon's usb(duracell)1516:1213
    dev_handle = libusb_open_device_with_vid_pid(ctx, 0951, 1689); //these are vendorID and productID I found for my usb device

    if (dev_handle == NULL){
        cout <<"Cannot open device "<< endl;
    }else{
        cout << "Device opened" << endl;
    }

    libusb_free_device_list(devs, 1);// free the list unref the devices in it

    unsigned char *data = new unsigned char[4];//data to write
    data[0] = 'a'; data[1] = 'b'; data[2] = 'c'; data[3] = 'd';//some dummy values

    int actual; //used to find how many bytes were written

    if (libusb_kernel_driver_active(dev_handle, 0) == 1){// findout if kernal driver attached
        cout << "Kernal Driver Active" << endl;
        if (libusb_detach_kernel_driver(dev_handle, 0) == 0 ){  //detach it
            cout<< "Kernal Driver Detached" << endl;
        }
    }

    r = libusb_claim_interface(dev_handle, 0);// claim interface 0 (the first) of devices

    if(r < 0){
        cout <<"Cannot claim interface "<<endl;
        return 1;
    }

    cout <<"Claimed interface "<<endl;

    cout<<"data->"<<data<<"<-"<<endl; // just to see the data we want to write : abcd
    cout<<"Writing data..."<<endl;

    r = libusb_bulk_transfer(dev_handle, (2 | LIBUSB_ENDPOINT_OUT), data, 4, &actual, 0);//my device's out endpoint was 2, found withe trial - the device had two endpoints: 2 and 129

    if(r == 0 && actual == 4){  // we wrote 4 bytes successfully
        cout<<"Writing successfull"<<endl;
    }else{
        cout<<"write error"<<endl;
    }

    r = libusb_release_interface(dev_handle, 0); // release the claimed interface

    if(r!=0) {
        cout<<"Cannot Release Interface"<<endl;
        return 1;
    }
    cout<<"Released interface"<<endl;
    libusb_close(dev_handle); // close the device we opened
    libusb_exit(ctx); // need to be called to end the

    delete[] data;// delete the allocated memory for data
    return 0;
}

但是当我使用以下命令行编译上述代码时(这些是我的 USB 的产品 ID 和供应商 ID)

dev_handle = libusb_open_device_with_vid_pid(ctx, 0951, 1689);

编译器抛出以下错误

transfer_data_libusb.cpp:30:55: error: invalid digit "9" in octal constant

有人建议我删除前导零,即(“951”而不是“0951”)但是当我这样做时,文件被成功编译,但是当我运行编译版本时,这会引发以下错误

7 Device in list 
Cannot open device 
Segmentation fault (core dumped)

不知道我该怎么办你能帮忙顺便说一句我使用下面的命令来编译上面的代码

g++ transfer_data_libusb.cpp $(pkg-config --libs libusb-1.0) -o transfer_data_libusb

非常感谢你的时间

4

2 回答 2

3

你的号码可能是十六进制的。采用:

0x951

而不是你的0951.

和:

0x1689

而不是你的1689.

如果您看到其他数字(我假设它是您的产品):

http://usbspeed.nirsoft.net/?g=32gb

他们必须af字符,所以这意味着格式应该是十六进制。

于 2013-02-26T11:23:02.350 回答
0

当您的通话失败时

dev_handle = libusb_open_device_with_vid_pid(ctx, 0951, 1689); 

dev_handle将为 NULL。

if (dev_handle == NULL){
    cout <<"Cannot open device "<< endl;
    //treat error here and quit

那时你需要停止操作dev_handle

于 2013-02-26T11:25:00.403 回答