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glibc  2.9
putgrent.c
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00001 /* Copyright (C) 1991,92,96,98,99,2000,2005 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <errno.h>
00020 #include <stdio.h>
00021 #include <grp.h>
00022 
00023 #ifdef USE_IN_LIBIO
00024 # define flockfile(s) _IO_flockfile (s)
00025 # define funlockfile(s) _IO_funlockfile (s)
00026 #endif
00027 
00028 #define _S(x) x ? x : ""
00029 
00030 /* Write an entry to the given stream.
00031    This must know the format of the group file.  */
00032 int
00033 putgrent (gr, stream)
00034      const struct group *gr;
00035      FILE *stream;
00036 {
00037   int retval;
00038 
00039   if (__builtin_expect (gr == NULL, 0) || __builtin_expect (stream == NULL, 0))
00040     {
00041       __set_errno (EINVAL);
00042       return -1;
00043     }
00044 
00045   flockfile (stream);
00046 
00047   if (gr->gr_name[0] == '+' || gr->gr_name[0] == '-')
00048     retval = fprintf (stream, "%s:%s::",
00049                     gr->gr_name, _S (gr->gr_passwd));
00050   else
00051     retval = fprintf (stream, "%s:%s:%lu:",
00052                     gr->gr_name, _S (gr->gr_passwd),
00053                     (unsigned long int) gr->gr_gid);
00054   if (__builtin_expect (retval, 0) < 0)
00055     {
00056       funlockfile (stream);
00057       return -1;
00058     }
00059 
00060   if (gr->gr_mem != NULL)
00061     {
00062       int i;
00063 
00064       for (i = 0 ; gr->gr_mem[i] != NULL; i++)
00065        if (fprintf (stream, i == 0 ? "%s" : ",%s", gr->gr_mem[i]) < 0)
00066          {
00067            /* What else can we do?  */
00068            funlockfile (stream);
00069            return -1;
00070          }
00071     }
00072 
00073   retval = fputc_unlocked ('\n', stream);
00074 
00075   funlockfile (stream);
00076 
00077   return retval < 0 ? -1 : 0;
00078 }