lib/hasmntopt.c

   1 /* hasmntopt() function: test for the presence of a mount option.
   2
   3    Copyright (C) 1995-2024 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include <mntent.h>
  22
  23 #include <string.h>
  24
  25 char *
  26 hasmntopt (const struct mntent *mnt, const char *opt)
  27 {
  28   const size_t optlen = strlen (opt);
  29   char *rest = mnt->mnt_opts, *p;
  30
  31   while ((p = strstr (rest, opt)) != NULL)
  32     {
  33       if ((p == rest || p[-1] == ',')
  34           && (p[optlen] == '\0' || p[optlen] == '=' || p[optlen] == ','))
  35         return p;
  36
  37       rest = strchr (p, ',');
  38       if (rest == NULL)
  39         break;
  40       ++rest;
  41     }
  42
  43   return NULL;
  44 }