grp/fgetgrent_r.c

   1 /* Copyright (C) 1991, 1996-1999, 2000, 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 <ctype.h>
  20 #include <errno.h>
  21 #include <grp.h>
  22 #include <stdio.h>
  23
  24 #include <libio/iolibio.h>
  25 #define flockfile(s) _IO_flockfile (s)
  26 #define funlockfile(s) _IO_funlockfile (s)
  27
  28 /* Define a line parsing function using the common code
  29    used in the nss_files module.  */
  30
  31 #define STRUCTURE       group
  32 #define ENTNAME         grent
  33 struct grent_data {};
  34
  35 #define TRAILING_LIST_MEMBER            gr_mem
  36 #define TRAILING_LIST_SEPARATOR_P(c)    ((c) == ',')
  37 #include <nss/nss_files/files-parse.c>
  38 LINE_PARSER
  39 (,
  40  STRING_FIELD (result->gr_name, ISCOLON, 0);
  41  if (line[0] == '\0'
  42      && (result->gr_name[0] == '+' || result->gr_name[0] == '-'))
  43    {
  44      result->gr_passwd = NULL;
  45      result->gr_gid = 0;
  46    }
  47  else
  48    {
  49      STRING_FIELD (result->gr_passwd, ISCOLON, 0);
  50      if (result->gr_name[0] == '+' || result->gr_name[0] == '-')
  51        INT_FIELD_MAYBE_NULL (result->gr_gid, ISCOLON, 0, 10, , 0)
  52      else
  53        INT_FIELD (result->gr_gid, ISCOLON, 0, 10,)
  54    }
  55  )
  56
  57
  58 /* Read one entry from the given stream.  */
  59 int
  60 __fgetgrent_r (FILE *stream, struct group *resbuf, char *buffer, size_t buflen,
  61                struct group **result)
  62 {
  63   char *p;
  64   int parse_result;
  65
  66   flockfile (stream);
  67   do
  68     {
  69       buffer[buflen - 1] = '\xff';
  70       p = fgets_unlocked (buffer, buflen, stream);
  71       if (__builtin_expect (p == NULL, 0) && feof_unlocked (stream))
  72         {
  73           funlockfile (stream);
  74           *result = NULL;
  75           __set_errno (ENOENT);
  76           return errno;
  77         }
  78       if (__builtin_expect (p == NULL, 0) || buffer[buflen - 1] != '\xff')
  79         {
  80           funlockfile (stream);
  81           *result = NULL;
  82           __set_errno (ERANGE);
  83           return errno;
  84         }
  85
  86       /* Skip leading blanks.  */
  87       while (isspace (*p))
  88         ++p;
  89     } while (*p == '\0' || *p == '#'    /* Ignore empty and comment lines.  */
  90              /* Parse the line.  If it is invalid, loop to
  91                 get the next line of the file to parse.  */
  92              || ! (parse_result = parse_line (p, resbuf,
  93                                               (void *) buffer, buflen,
  94                                               &errno)));
  95
  96   funlockfile (stream);
  97
  98   if (__builtin_expect (parse_result, 0) == -1)
  99     {
 100       /* The parser ran out of space.  */
 101       *result = NULL;
 102       return errno;
 103     }
 104
 105   *result = resbuf;
 106   return 0;
 107 }
 108 weak_alias (__fgetgrent_r, fgetgrent_r)