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;
  28
  29         while ((dev = devs[i++]) != NULL) {
  30                 struct libusb_device_descriptor desc;
  31                 int r = libusb_get_device_descriptor(dev, &desc);
  32                 if (r < 0) {
  33                         fprintf(stderr, "failed to get device descriptor");
  34                         return;
  35                 }
  36
  37                 printf("%04x:%04x (bus %d, device %d)\n",
  38                         desc.idVendor, desc.idProduct,
  39                         libusb_get_bus_number(dev), libusb_get_device_address(dev));
  40         }
  41 }
  42
  43 int main(void)
  44 {
  45         libusb_device **devs;
  46         int r;
  47         ssize_t cnt;
  48
  49         r = libusb_init(NULL);
  50         if (r < 0)
  51                 return r;
  52
  53         cnt = libusb_get_device_list(NULL, &devs);
  54         if (cnt < 0)
  55                 return (int) cnt;
  56
  57         print_devs(devs);
  58         libusb_free_device_list(devs, 1);
  59
  60         libusb_exit(NULL);
  61         return 0;
  62 }