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