gnu/dist/gdb6/sim/m32c/safe-fgets.c

   1 /* safe-fgets.c --- like fgets, but allocates its own static buffer.
   2
   3 Copyright (C) 2005 Free Software Foundation, Inc.
   4 Contributed by Red Hat, Inc.
   5
   6 This file is part of the GNU simulators.
   7
   8 The GNU simulators are free software; you can redistribute them and/or
   9 modify them under the terms of the GNU General Public License as
  10 published by the Free Software Foundation; either version 2 of the
  11 License, or (at your option) any later version.
  12
  13 The GNU simulators are distributed in the hope that they will be
  14 useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16 General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with the GNU simulators; if not, write to the Free Software
  20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21 02110-1301, USA  */
  22
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26
  27 #include "safe-fgets.h"
  28
  29 static char *line_buf = 0;
  30 static int line_buf_size = 0;
  31
  32 #define LBUFINCR 100
  33
  34 char *
  35 safe_fgets (FILE *f)
  36 {
  37   char *line_ptr;
  38
  39   if (line_buf == 0)
  40     {
  41       line_buf = (char *) malloc (LBUFINCR);
  42       line_buf_size = LBUFINCR;
  43     }
  44
  45   /* points to last byte */
  46   line_ptr = line_buf + line_buf_size - 1;
  47
  48   /* so we can see if fgets put a 0 there */
  49   *line_ptr = 1;
  50   if (fgets (line_buf, line_buf_size, f) == 0)
  51     return 0;
  52
  53   /* we filled the buffer? */
  54   while (line_ptr[0] == 0 && line_ptr[-1] != '\n')
  55     {
  56       /* Make the buffer bigger and read more of the line */
  57       line_buf_size += LBUFINCR;
  58       line_buf = (char *) realloc (line_buf, line_buf_size);
  59
  60       /* points to last byte again */
  61       line_ptr = line_buf + line_buf_size - 1;
  62       /* so we can see if fgets put a 0 there */
  63       *line_ptr = 1;
  64
  65       if (fgets (line_buf + line_buf_size - LBUFINCR - 1, LBUFINCR + 1, f) ==
  66           0)
  67         return 0;
  68     }
  69
  70   return line_buf;
  71 }