grub/kern/rescue_reader.c

/* rescue_reader.c - rescue mode reader  */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2009  Free Software Foundation, Inc.
 *
 *  GRUB 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.
 *
 *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <grub/types.h>
#include <grub/reader.h>
#include <grub/misc.h>
#include <grub/term.h>

#define GRUB_RESCUE_BUF_SIZE	256

static char linebuf[GRUB_RESCUE_BUF_SIZE];

static grub_err_t
grub_rescue_init (void)
{
  grub_printf ("Entering rescue mode...\n");
  return 0;
}

/* Prompt to input a command and read the line.  */
static grub_err_t
grub_rescue_read_line (char **line, int cont)
{
  int c;
  int pos = 0;

  grub_printf ((cont) ? "> " : "grub rescue> ");
  grub_memset (linebuf, 0, GRUB_RESCUE_BUF_SIZE);

  while ((c = GRUB_TERM_ASCII_CHAR (grub_getkey ())) != '\n' && c != '\r')
    {
      if (grub_isprint (c))
	{
	  if (pos < GRUB_RESCUE_BUF_SIZE - 1)
	    {
	      linebuf[pos++] = c;
	      grub_putchar (c);
	    }
	}
      else if (c == '\b')
	{
	  if (pos > 0)
	    {
	      linebuf[--pos] = 0;
	      grub_putchar (c);
	      grub_putchar (' ');
	      grub_putchar (c);
	    }
	}
      grub_refresh ();
    }

  grub_putchar ('\n');
  grub_refresh ();

  *line = grub_strdup (linebuf);

  return 0;
}

static struct grub_reader grub_rescue_reader =
  {
    .name = "rescue",
    .init = grub_rescue_init,
    .read_line = grub_rescue_read_line
  };

void
grub_register_rescue_reader (void)
{
  grub_reader_register ("rescue", &grub_rescue_reader);
}