linux下使用libusb 进行获取设备描述符c代码

在Linux环境下使用libusb进行设备描述符的获取，首先需要包含必要的库头文件并初始化libusb环境。以下是一个简单的C语言示例代码片段，展示了如何连接到USB设备并读取其描述符：

#include <stdio.h>
#include <libusb.h>

int main(int argc, char* argv[]) {
    // 初始化libusb库
    int result = libusb_init(NULL);
    if (result != LIBUSB_SUCCESS) {
        fprintf(stderr, "Failed to initialize libusb: %s\n",
                libusb_error_name(result));
        return 1;
    }

    // 找到USB设备
    struct libusb_device* device;
    result = libusb_get_device_list(NULL, &device_list);
    if (result != LIBUSB_SUCCESS) {
        fprintf(stderr, "Failed to get devices: %s\n",
                libusb_error_name(result));
        goto exit_with_cleanup;
    }
    
    // 遍历找到的设备
    for (struct libusb_device *d = device_list; d != NULL; d = d->next) {
        // 检查设备是否为我们需要的
        const char* vendor_id = libusb_get_device_string(d, USB_DESC_ID_VENDOR);
        const char* product_id = libusb_get_device_string(d, USB_DESC_ID_PRODUCT);
        
        // 如果设备ID匹配，尝试打开设备
        if (strcmp(vendor_id, VENDOR_ID) == 0 && strcmp(product_id, PRODUCT_ID) == 0) {
            result = libusb_open(d, &device_handle);
            if (result == LIBUSB_SUCCESS) {
                break;
            } else {
                fprintf(stderr, "Failed to open device: %s\n",
                        libusb_error_name(result));
            }
        }
    }

    // 如果设备打开成功，获取描述符
    if (result == LIBUSB_SUCCESS) {
        libusb_device_descriptor desc;
        memset(&desc, 0, sizeof(desc));
        result = libusb_get_device_descriptor(device_handle, &desc);
        if (result == LIBUSB_SUCCESS) {
            printf("Device Descriptor:\n");
            printf("\tClass: %x\n", desc.bDeviceClass);
            // ... 打印其他描述符信息
        } else {
            fprintf(stderr, "Failed to get device descriptor: %s\n",
                    libusb_error_name(result));
        }
    }

exit_with_cleanup:
    // 清理并关闭资源
    libusb_free_device_list(device_list, 1);
    if (device_handle != NULL) {
        libusb_close(device_handle);
    }
    libusb_exit(NULL);

    return result == LIBUSB_SUCCESS ? 0 : 1;
}

在这个例子中，你需要替换 `VENDOR_ID` 和 `PRODUCT_ID` 为实际的USB设备厂商ID和产品ID。记得在运行前安装libusb开发库 (`sudo apt-1.0-0-dev`)。