1  /* Parsing of Suboptions Example
       2     Copyright (C) 1991-2023 Free Software Foundation, Inc.
       3  
       4     This program is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU General Public License
       6     as published by the Free Software Foundation; either version 2
       7     of the License, or (at your option) any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program; if not, see <https://www.gnu.org/licenses/>.
      16  */
      17  
      18  #include <stdio.h>
      19  #include <stdlib.h>
      20  #include <unistd.h>
      21  
      22  int do_all;
      23  const char *type;
      24  int read_size;
      25  int write_size;
      26  int read_only;
      27  
      28  enum
      29  {
      30    RO_OPTION = 0,
      31    RW_OPTION,
      32    READ_SIZE_OPTION,
      33    WRITE_SIZE_OPTION,
      34    THE_END
      35  };
      36  
      37  const char *mount_opts[] =
      38  {
      39    [RO_OPTION] = "ro",
      40    [RW_OPTION] = "rw",
      41    [READ_SIZE_OPTION] = "rsize",
      42    [WRITE_SIZE_OPTION] = "wsize",
      43    [THE_END] = NULL
      44  };
      45  
      46  int
      47  main (int argc, char **argv)
      48  {
      49    char *subopts, *value;
      50    int opt;
      51  
      52    while ((opt = getopt (argc, argv, "at:o:")) != -1)
      53      switch (opt)
      54        {
      55        case 'a':
      56          do_all = 1;
      57          break;
      58        case 't':
      59          type = optarg;
      60          break;
      61        case 'o':
      62          subopts = optarg;
      63          while (*subopts != '\0')
      64            switch (getsubopt (&subopts, mount_opts, &value))
      65              {
      66              case RO_OPTION:
      67                read_only = 1;
      68                break;
      69              case RW_OPTION:
      70                read_only = 0;
      71                break;
      72              case READ_SIZE_OPTION:
      73                if (value == NULL)
      74                  abort ();
      75                read_size = atoi (value);
      76                break;
      77              case WRITE_SIZE_OPTION:
      78                if (value == NULL)
      79                  abort ();
      80                write_size = atoi (value);
      81                break;
      82              default:
      83                /* Unknown suboption.  */
      84                printf ("Unknown suboption `%s'\n", value);
      85                break;
      86              }
      87          break;
      88        default:
      89          abort ();
      90        }
      91  
      92    /* Do the real work.  */
      93  
      94    return 0;
      95  }