sim/m32c/safe-fgets.c

   1 /* safe-fgets.c --- like fgets, but allocates its own static buffer.
   2
   3 Copyright (C) 2005, 2007, 2008, 2009, 2010, 2011
   4 Free Software Foundation, Inc.
   5 Contributed by Red Hat, Inc.
   6
   7 This file is part of the GNU simulators.
   8
   9 This program is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 This program is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25
  26 #include "safe-fgets.h"
  27
  28 static char *line_buf = 0;
  29 static int line_buf_size = 0;
  30
  31 #define LBUFINCR 100
  32
  33 char *
  34 safe_fgets (FILE * f)
  35 {
  36   char *line_ptr;
  37
  38   if (line_buf == 0)
  39     {
  40       line_buf = (char *) malloc (LBUFINCR);
  41       line_buf_size = LBUFINCR;
  42     }
  43
  44   /* points to last byte */
  45   line_ptr = line_buf + line_buf_size - 1;
  46
  47   /* so we can see if fgets put a 0 there */
  48   *line_ptr = 1;
  49   if (fgets (line_buf, line_buf_size, f) == 0)
  50     return 0;
  51
  52   /* we filled the buffer? */
  53   while (line_ptr[0] == 0 && line_ptr[-1] != '\n')
  54     {
  55       /* Make the buffer bigger and read more of the line */
  56       line_buf_size += LBUFINCR;
  57       line_buf = (char *) realloc (line_buf, line_buf_size);
  58
  59       /* points to last byte again */
  60       line_ptr = line_buf + line_buf_size - 1;
  61       /* so we can see if fgets put a 0 there */
  62       *line_ptr = 1;
  63
  64       if (fgets (line_buf + line_buf_size - LBUFINCR - 1, LBUFINCR + 1, f) ==
  65           0)
  66         return 0;
  67     }
  68
  69   return line_buf;
  70 }