/* safe-fgets.c --- like fgets, but allocates its own static buffer.

Copyright (C) 2005, 2007 Free Software Foundation, Inc.
Contributed by Red Hat, Inc.

This file is part of the GNU simulators.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.  */


#include <stdio.h>
#include <stdlib.h>

#include "safe-fgets.h"

static char *line_buf = 0;
static int line_buf_size = 0;

#define LBUFINCR 100

char *
safe_fgets (FILE *f)
{
  char *line_ptr;

  if (line_buf == 0)
    {
      line_buf = (char *) malloc (LBUFINCR);
      line_buf_size = LBUFINCR;
    }

  /* points to last byte */
  line_ptr = line_buf + line_buf_size - 1;

  /* so we can see if fgets put a 0 there */
  *line_ptr = 1;
  if (fgets (line_buf, line_buf_size, f) == 0)
    return 0;

  /* we filled the buffer? */
  while (line_ptr[0] == 0 && line_ptr[-1] != '\n')
    {
      /* Make the buffer bigger and read more of the line */
      line_buf_size += LBUFINCR;
      line_buf = (char *) realloc (line_buf, line_buf_size);

      /* points to last byte again */
      line_ptr = line_buf + line_buf_size - 1;
      /* so we can see if fgets put a 0 there */
      *line_ptr = 1;

      if (fgets (line_buf + line_buf_size - LBUFINCR - 1, LBUFINCR + 1, f) ==
	  0)
	return 0;
    }

  return line_buf;
}