getpwent_replace.c

   1 /*
   2   a replacement for getpwent() on AIX that enumerates
   3   all user databases, not just /etc/passwd
   4
   5   Andrew Tridgell tridge@au.ibm.com
   6   February 2004
   7 */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <pwd.h>
  13 #include <usersec.h>
  14 #include <sys/types.h>
  15
  16
  17 static struct {
  18         char *all_users;
  19         char *next;
  20 } getpwent_state;
  21
  22
  23 /*
  24   free up any resources associated with getpwent()
  25 */
  26 void endpwent(void)
  27 {
  28         if (getpwent_state.all_users) {
  29                 free(getpwent_state.all_users);
  30         }
  31         getpwent_state.all_users = NULL;
  32         getpwent_state.next = NULL;
  33 }
  34
  35
  36 /*
  37   reset the state to the start of the user database
  38 */
  39 void setpwent(void)
  40 {
  41         char *s;
  42         endpwent();
  43         /* getuserattr returns a null separated list of users,
  44            with each user being of the form REGISTRY:USERNAME */
  45         if (getuserattr("ALL", "users", &s, SEC_CHAR) == 0) {
  46                 getpwent_state.all_users = s;
  47                 getpwent_state.next = getpwent_state.all_users;
  48         }
  49
  50 }
  51
  52 /*
  53   get the next user
  54 */
  55 struct passwd *getpwent(void)
  56 {
  57         char *user;
  58         struct passwd *pwd;
  59         if (!getpwent_state.all_users) {
  60                 setpwent();
  61                 if (!getpwent_state.all_users) {
  62                         return NULL;
  63                 }
  64         }
  65         do {
  66                 user = getpwent_state.next;
  67                 if (!*user) {
  68                         endpwent();
  69                         return NULL;
  70                 }
  71                 user = strchr(user, ':');
  72                 if (!user) {
  73                         endpwent();
  74                         return NULL;
  75                 }
  76                 pwd = getpwnam(user+1);
  77                 getpwent_state.next += strlen(getpwent_state.next)+1;
  78         } while (!pwd);
  79
  80         return pwd;
  81 }
  82
  83
  84 #if TEST_PROGRAM
  85 int main(void)
  86 {
  87         struct passwd *pwd;
  88
  89         setpwent();
  90
  91         while ((pwd = getpwent())) {
  92                 printf("%s\n", pwd->pw_name);
  93         }
  94
  95         endpwent();
  96
  97         return 0;
  98 }
  99 #endif