C 使用libusb的输出不正确

我用libusb做了一个程序。我怀疑输出是否正确，因为所有条目都显示相同的供应商和产品id。代码如下：

#include <stdio.h>
#include <stdlib.h>
#include <libusb-1.0/libusb.h>

void print_devices(libusb_device *dev)
{
    struct libusb_device_descriptor desc;
    struct libusb_config_descriptor *config;

    const struct libusb_interface *inter;
    const struct libusb_interface_descriptor *interdesc;
    const struct libusb_endpoint_descriptor *endpointdesc;

    int ret;
    int i,j,k;

    if(ret<0)
    {   
        fprintf(stderr,"error in getting device descriptor\n");
        return;
    }

    printf("Number of possible configs is %d\n",desc.bNumConfigurations);
    printf("Vendor: %d\n",desc.idVendor);
    printf("Product ID: %d\n",desc.idProduct);

    libusb_get_config_descriptor(dev, 0, &config);

    printf("Interface: %d\n", config->bNumInterfaces);
    printf("\n\n"); 
}


int main(int argc,char *argv[])
{
    libusb_device **devs;
    libusb_context *context = NULL;

    size_t list;
    size_t i;

    int ret,temp;

    ret = libusb_init(&context);

    if(ret < 0)
    {
        perror("libusb_init");
        exit(1);
    }

    list = libusb_get_device_list(context, &devs);

    if(list < 0)
    {
        fprintf(stderr, "Error in getting device list\n");
        libusb_free_device_list(devs, 1);
        libusb_exit(context);
        exit(1);
    }

    temp=(int)list;
    printf("\n%d devices found\n\n",temp);

    for(i=0;i<temp;i++)
    {
        //print devices
        print_devices(devs[i]);
    }

    libusb_free_device_list(devs, 1);
    libusb_exit(context);

    return 0;
}

这是lsusb显示的内容：

anubhav@anubhav-Inspiron-3421:~/Desktop/usb$ lsusb
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 004: ID 064e:812c Suyin Corp. 
Bus 001 Device 007: ID 0a5c:21d7 Broadcom Corp. BCM43142 Bluetooth 4.0
Bus 001 Device 003: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

---

需要帮助查找错误（如果有）。

一定是在某个地方意外跳过了一行。。。我建议您添加以下行，否则

ret

将被单位化：

int ret;
int i,j,k;

ret = libusb_get_device_descriptor(dev, &desc);//this line !
if(ret<0)
{   
    fprintf(stderr,"error in getting device descriptor\n");
    return;
}

---

下面的问题有助于找到丢失的行。这一行帮助我链接了

libusb

it建议通过

gcc-main.c-o-main-lusb-1.0

进行编译是的，您提到的那一行应该被添加。我得到了预期的输出。谢谢。我可以通过libusb而不是lsusb命令获取有关usb设备的任何信息吗？

lsusb

似乎基于

libusb

…如果键入

lsusb-v

，您将获得大量有关usb设备的数据。在程序中使用它的方式比调用

system

和解析文件更干净、更优雅……我无法告诉您

libusb

是否能够提供比

lsusb

更多的数据。

int ret;
int i,j,k;

ret = libusb_get_device_descriptor(dev, &desc);//this line !
if(ret<0)
{   
    fprintf(stderr,"error in getting device descriptor\n");
    return;
}

printf("Vendor: %x\n",desc.idVendor);
printf("Product ID: %x\n",desc.idProduct);