text: #include <stdio.h>
  #include <unistd.h>
  #include <grp.h>
  #include <pwd.h>
  #include <sys/types.h>
  
  int main(int argc, char **argv)
  {
  	int result, ngroups, i;
  	gid_t *groups;
  	struct passwd *pw;
  
  	if (!(pw = getpwnam(argv[1]))) {
  		printf("FAIL: no passwd entry for %s\n", argv[1]);
  		return 1;
  	}
  
  	result = initgroups(argv[1], pw->pw_gid);
  
  	if (result == -1) {
  		printf("FAIL");
  		return 1;
  	}
  
  	ngroups = getgroups(0, NULL);
  
  	groups = (gid_t *)malloc(sizeof(gid_t) * ngroups);
  	ngroups = getgroups(ngroups, groups);
  
  	printf("%s is a member of groups:\n", argv[1]);
  
  	for (i = 0; i < ngroups; i++) {
  		struct group *grp;
  
  		grp = getgrgid(groups[i]);
  
  		printf("%d (%s)\n", groups[i], grp ? grp->gr_name : "?");
  	}
  
  	printf("PASS\n");
  	return 0;
  }
  