grp/putgrent.c

   1 /* Copyright (C) 1991,92,96,98,99,2000,2005,2011 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <stdio.h>
  21 #include <grp.h>
  22
  23 #define flockfile(s) _IO_flockfile (s)
  24 #define funlockfile(s) _IO_funlockfile (s)
  25
  26 #define _S(x)   x ? x : ""
  27
  28 /* Write an entry to the given stream.
  29    This must know the format of the group file.  */
  30 int
  31 putgrent (gr, stream)
  32      const struct group *gr;
  33      FILE *stream;
  34 {
  35   int retval;
  36
  37   if (__builtin_expect (gr == NULL, 0) || __builtin_expect (stream == NULL, 0))
  38     {
  39       __set_errno (EINVAL);
  40       return -1;
  41     }
  42
  43   flockfile (stream);
  44
  45   if (gr->gr_name[0] == '+' || gr->gr_name[0] == '-')
  46     retval = fprintf (stream, "%s:%s::",
  47                       gr->gr_name, _S (gr->gr_passwd));
  48   else
  49     retval = fprintf (stream, "%s:%s:%lu:",
  50                       gr->gr_name, _S (gr->gr_passwd),
  51                       (unsigned long int) gr->gr_gid);
  52   if (__builtin_expect (retval, 0) < 0)
  53     {
  54       funlockfile (stream);
  55       return -1;
  56     }
  57
  58   if (gr->gr_mem != NULL)
  59     {
  60       int i;
  61
  62       for (i = 0 ; gr->gr_mem[i] != NULL; i++)
  63         if (fprintf (stream, i == 0 ? "%s" : ",%s", gr->gr_mem[i]) < 0)
  64           {
  65             /* What else can we do?  */
  66             funlockfile (stream);
  67             return -1;
  68           }
  69     }
  70
  71   retval = fputc_unlocked ('\n', stream);
  72
  73   funlockfile (stream);
  74
  75   return retval < 0 ? -1 : 0;
  76 }