examples/listdevs.c

   1 /*
   2  * libusbx example program to list devices on the bus
   3  * Copyright © 2007 Daniel Drake <dsd@gentoo.org>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include <stdio.h>
  21
  22 #include "libusb.h"
  23
  24 static void print_devs(libusb_device **devs)
  25 {
  26         libusb_device *dev;
  27         int i = 0, j = 0;
  28         uint8_t path[8];
  29
  30         while ((dev = devs[i++]) != NULL) {
  31                 struct libusb_device_descriptor desc;
  32                 int r = libusb_get_device_descriptor(dev, &desc);
  33                 if (r < 0) {
  34                         fprintf(stderr, "failed to get device descriptor");
  35                         return;
  36                 }
  37
  38                 printf("%04x:%04x (bus %d, device %d)",
  39                         desc.idVendor, desc.idProduct,
  40                         libusb_get_bus_number(dev), libusb_get_device_address(dev));
  41
  42                 r = libusb_get_port_numbers(dev, path, sizeof(path));
  43                 if (r > 0) {
  44                         printf(" path: %d", path[0]);
  45                         for (j = 1; j < r; j++)
  46                                 printf(".%d", path[j]);
  47                 }
  48                 printf("\n");
  49         }
  50 }
  51
  52 int main(void)
  53 {
  54         libusb_device **devs;
  55         int r;
  56         ssize_t cnt;
  57
  58         r = libusb_init(NULL);
  59         if (r < 0)
  60                 return r;
  61
  62         cnt = libusb_get_device_list(NULL, &devs);
  63         if (cnt < 0)
  64                 return (int) cnt;
  65
  66         print_devs(devs);
  67         libusb_free_device_list(devs, 1);
  68
  69         libusb_exit(NULL);
  70         return 0;
  71 }