grp/putgrent.c

   1 /* Copyright (C) 1991, 1992, 1996, 1998, 1999 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 not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <errno.h>
  20 #include <stdio.h>
  21 #include <grp.h>
  22
  23 #ifdef USE_IN_LIBIO
  24 # define flockfile(s) _IO_flockfile (s)
  25 # define funlockfile(s) _IO_funlockfile (s)
  26 #endif
  27
  28 #define _S(x)   x ? x : ""
  29
  30 /* Write an entry to the given stream.
  31    This must know the format of the group file.  */
  32 int
  33 putgrent (gr, stream)
  34      const struct group *gr;
  35      FILE *stream;
  36 {
  37   int retval;
  38
  39   if (gr == NULL || stream == NULL)
  40     {
  41       __set_errno (EINVAL);
  42       return -1;
  43     }
  44
  45   flockfile (stream);
  46
  47   retval = fprintf (stream, "%s:%s:%u:",
  48                     gr->gr_name, _S (gr->gr_passwd), gr->gr_gid);
  49   if (retval < 0)
  50     return -1;
  51
  52   if (gr->gr_mem != NULL)
  53     {
  54       int i;
  55
  56       for (i = 0 ; gr->gr_mem[i] != NULL; i++)
  57         if (fprintf (stream, i == 0 ? "%s" : ",%s", gr->gr_mem[i]) < 0)
  58           {
  59             /* What else can we do?  */
  60             funlockfile (stream);
  61             return -1;
  62           }
  63     }
  64
  65   retval = fputc_unlocked ('\n', stream);
  66
  67   funlockfile (stream);
  68
  69   return retval < 0 ? -1 : 0;
  70 }