src/udev/udevadm-util.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (C) 2008-2009 Kay Sievers <kay@vrfy.org>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program 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
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "path-util.h"
  20 #include "string-util.h"
  21 #include "udevadm-util.h"
  22
  23 struct udev_device *find_device(struct udev *udev,
  24                                 const char *id,
  25                                 const char *prefix) {
  26
  27         assert(udev);
  28         assert(id);
  29
  30         if (prefix && !startswith(id, prefix))
  31                 id = strjoina(prefix, id);
  32
  33         if (path_startswith(id, "/dev/")) {
  34                 struct stat statbuf;
  35                 char type;
  36
  37                 if (stat(id, &statbuf) < 0)
  38                         return NULL;
  39
  40                 if (S_ISBLK(statbuf.st_mode))
  41                         type = 'b';
  42                 else if (S_ISCHR(statbuf.st_mode))
  43                         type = 'c';
  44                 else
  45                         return NULL;
  46
  47                 return udev_device_new_from_devnum(udev, type, statbuf.st_rdev);
  48         } else if (path_startswith(id, "/sys/"))
  49                 return udev_device_new_from_syspath(udev, id);
  50         else
  51                 return NULL;
  52 }