getgrent_replace.c

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