grp/getgrent.c

   1 /* Copyright (C) 1991 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <stddef.h>
  21 #include <stdio.h>
  22 #include <grp.h>
  23
  24 static FILE *stream = NULL;
  25
  26 /* Rewind the stream.  */
  27 void
  28 DEFUN_VOID(setgrent)
  29 {
  30   if (stream != NULL)
  31     rewind(stream);
  32 }
  33
  34
  35 /* Close the stream.  */
  36 void
  37 DEFUN_VOID(endgrent)
  38 {
  39   if (stream != NULL)
  40     {
  41       (void) fclose(stream);
  42       stream = NULL;
  43     }
  44 }
  45
  46
  47 /* Read an entry from the stream.  */
  48 struct group *
  49 DEFUN_VOID(getgrent)
  50 {
  51   static PTR info = NULL;
  52   if (info == NULL)
  53     {
  54       info = __grpalloc();
  55       if (info == NULL)
  56         return(NULL);
  57     }
  58
  59   if (stream == NULL)
  60     {
  61       stream = __grpopen();
  62       if (stream == NULL)
  63         return(NULL);
  64     }
  65
  66   return(__grpread(stream, info));
  67 }