grub-core/kern/rescue_reader.c

   1 /* rescue_reader.c - rescue mode reader  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2009,2010  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/types.h>
  21 #include <grub/reader.h>
  22 #include <grub/parser.h>
  23 #include <grub/misc.h>
  24 #include <grub/term.h>
  25 #include <grub/mm.h>
  26
  27 #define GRUB_RESCUE_BUF_SIZE    256
  28
  29 static char linebuf[GRUB_RESCUE_BUF_SIZE];
  30
  31 /* Prompt to input a command and read the line.  */
  32 static grub_err_t
  33 grub_rescue_read_line (char **line, int cont,
  34                        void *data __attribute__ ((unused)))
  35 {
  36   int c;
  37   int pos = 0;
  38   char str[4];
  39
  40   grub_printf ((cont) ? "> " : "grub rescue> ");
  41   grub_memset (linebuf, 0, GRUB_RESCUE_BUF_SIZE);
  42
  43   while ((c = grub_getkey ()) != '\n' && c != '\r')
  44     {
  45       if (grub_isprint (c))
  46         {
  47           if (pos < GRUB_RESCUE_BUF_SIZE - 1)
  48             {
  49               str[0] = c;
  50               str[1] = 0;
  51               linebuf[pos++] = c;
  52               grub_xputs (str);
  53             }
  54         }
  55       else if (c == '\b')
  56         {
  57           if (pos > 0)
  58             {
  59               str[0] = c;
  60               str[1] = ' ';
  61               str[2] = c;
  62               str[3] = 0;
  63               linebuf[--pos] = 0;
  64               grub_xputs (str);
  65             }
  66         }
  67       grub_refresh ();
  68     }
  69
  70   grub_xputs ("\n");
  71   grub_refresh ();
  72
  73   *line = grub_strdup (linebuf);
  74
  75   return 0;
  76 }
  77
  78 void __attribute__ ((noreturn))
  79 grub_rescue_run (void)
  80 {
  81 #ifdef QUIET_BOOT
  82   grub_printf ("Entering rescue mode...\n");
  83 #endif
  84
  85   while (1)
  86     {
  87       char *line;
  88
  89       /* Print an error, if any.  */
  90       grub_print_error ();
  91       grub_errno = GRUB_ERR_NONE;
  92
  93       grub_rescue_read_line (&line, 0, NULL);
  94       if (! line || line[0] == '\0')
  95         continue;
  96
  97       grub_rescue_parse_line (line, grub_rescue_read_line, NULL);
  98       grub_free (line);
  99     }
 100 }