source/tests/getgroups.c

   1 /* this tests whether getgroups actually returns lists of integers
   2    rather than gid_t. The test only works if the user running
   3    the test is in at least 1 group
   4
   5    The test is designed to check for those broken OSes that define
   6    getgroups() as returning an array of gid_t but actually return a
   7    array of ints! Ultrix is one culprit
   8   */
   9
  10 #include <sys/types.h>
  11 #include <stdio.h>
  12 #include <unistd.h>
  13 #include <grp.h>
  14
  15 main()
  16 {
  17         int i;
  18         int *igroups;
  19         char *cgroups;
  20         int grp = 0;
  21         int  ngroups = getgroups(0,&grp);
  22
  23         if (sizeof(gid_t) == sizeof(int)) {
  24                 fprintf(stderr,"gid_t and int are the same size\n");
  25                 exit(1);
  26         }
  27
  28         if (ngroups <= 0)
  29                 ngroups = 32;
  30
  31         igroups = (int *)malloc(sizeof(int)*ngroups);
  32
  33         for (i=0;i<ngroups;i++)
  34                 igroups[i] = 0x42424242;
  35
  36         ngroups = getgroups(ngroups,(gid_t *)igroups);
  37
  38         if (igroups[0] == 0x42424242)
  39                 ngroups = 0;
  40
  41         if (ngroups == 0) {
  42                 printf("WARNING: can't determine getgroups return type\n");
  43                 exit(1);
  44         }
  45
  46         cgroups = (char *)igroups;
  47
  48         if (ngroups == 1 &&
  49             cgroups[2] == 0x42 && cgroups[3] == 0x42) {
  50                 fprintf(stderr,"getgroups returns gid_t\n");
  51                 exit(1);
  52         }
  53
  54         for (i=0;i<ngroups;i++) {
  55                 if (igroups[i] == 0x42424242) {
  56                         fprintf(stderr,"getgroups returns gid_t\n");
  57                         exit(1);
  58                 }
  59         }
  60
  61         exit(0);
  62 }