manual/examples/db.c

   1 #include <grp.h>
   2 #include <pwd.h>
   3 #include <sys/types.h>
   4 #include <unistd.h>
   5 #include <stdlib.h>
   6
   7 int
   8 main (void)
   9 {
  10   uid_t me;
  11   struct passwd *my_passwd;
  12   struct group *my_group;
  13   char **members;
  14
  15   /* Get information about the user ID. */
  16   me = getuid ();
  17   my_passwd = getpwuid (me);
  18   if (!my_passwd)
  19     {
  20       printf ("Couldn't find out about user %d.\n", (int) me);
  21       exit (EXIT_FAILURE);
  22     }
  23
  24   /* Print the information. */
  25   printf ("I am %s.\n", my_passwd->pw_gecos);
  26   printf ("My login name is %s.\n", my_passwd->pw_name);
  27   printf ("My uid is %d.\n", (int) (my_passwd->pw_uid));
  28   printf ("My home directory is %s.\n", my_passwd->pw_dir);
  29   printf ("My default shell is %s.\n", my_passwd->pw_shell);
  30
  31   /* Get information about the default group ID. */
  32   my_group = getgrgid (my_passwd->pw_gid);
  33   if (!my_group)
  34     {
  35       printf ("Couldn't find out about group %d.\n",
  36               (int) my_passwd->pw_gid);
  37       exit (EXIT_FAILURE);
  38     }
  39
  40   /* Print the information. */
  41   printf ("My default group is %s (%d).\n",
  42           my_group->gr_name, (int) (my_passwd->pw_gid));
  43   printf ("The members of this group are:\n");
  44   members = my_group->gr_mem;
  45   while (*members)
  46     {
  47       printf ("  %s\n", *(members));
  48       members++;
  49     }
  50
  51   return EXIT_SUCCESS;
  52 }