linux usb设备通信

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

int main() {
    libusb_device **devs;
    libusb_device_handle *dev_handle;
    ssize_t cnt;
    int r;

    r = libusb_init(NULL);
    if (r < 0) {
        fprintf(stderr, "Init Error %d\n", r);
        return 1;
    }

    cnt = libusb_get_device_list(NULL, &devs);
    if (cnt < 0) {
        fprintf(stderr, "Get Device Error\n");
        libusb_exit(NULL);
        return 1;
    }

    for (ssize_t i = 0; i < cnt; ++i) {
        libusb_device *dev = devs[i];
        struct libusb_device_descriptor desc;
        r = libusb_get_device_descriptor(dev, &desc);
        if (r < 0) {
            fprintf(stderr, "Failed to get device descriptor\n");
            continue;
        }
        printf("Device Descriptor:\n"
               "  bLength             %5d\n"
               "  bDescriptorType     %5d\n"
               "  bcdUSB              %2x.%02x\n"
               "  idVendor            0x%04x\n"
               "  idProduct           0x%04x\n"
               "  bcdDevice           %2x.%02x\n",
               desc.bLength,
               desc.bDescriptorType,
               desc.bcdUSB >> 8, desc.bcdUSB & 0xff,
               desc.idVendor, desc.idProduct,
               desc.bcdDevice >> 8, desc.bcdDevice & 0xff);
    }

    libusb_free_device_list(devs, 1);
    libusb_exit(NULL);
    return 0;
}