arch/all-pc/boot/grub2-aros/grub-core/commands/echo.c

   1 /* echo.c - Command to display a line of text  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2006,2007,2010  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/dl.h>
  21 #include <grub/misc.h>
  22 #include <grub/extcmd.h>
  23 #include <grub/i18n.h>
  24 #include <grub/term.h>
  25
  26 GRUB_MOD_LICENSE ("GPLv3+");
  27
  28 static const struct grub_arg_option options[] =
  29   {
  30     {0, 'n', 0, N_("Do not output the trailing newline."), 0, 0},
  31     {0, 'e', 0, N_("Enable interpretation of backslash escapes."), 0, 0},
  32     {0, 0, 0, 0, 0, 0}
  33   };
  34
  35 static grub_err_t
  36 grub_cmd_echo (grub_extcmd_context_t ctxt, int argc, char **args)
  37 {
  38   struct grub_arg_list *state = ctxt->state;
  39   int newline = 1;
  40   int i;
  41
  42   /* Check if `-n' was used.  */
  43   if (state[0].set)
  44     newline = 0;
  45
  46   for (i = 0; i < argc; i++)
  47     {
  48       char *arg = *args;
  49       /* Unescaping results in a string no longer than the original.  */
  50       char *unescaped = grub_malloc (grub_strlen (arg) + 1);
  51       char *p = unescaped;
  52       args++;
  53
  54       if (!unescaped)
  55         return grub_errno;
  56
  57       while (*arg)
  58         {
  59           /* In case `-e' is used, parse backslashes.  */
  60           if (*arg == '\\' && state[1].set)
  61             {
  62               arg++;
  63               if (*arg == '\0')
  64                 break;
  65
  66               switch (*arg)
  67                 {
  68                 case '\\':
  69                   *p++ = '\\';
  70                   break;
  71
  72                 case 'a':
  73                   *p++ = '\a';
  74                   break;
  75
  76                 case 'c':
  77                   newline = 0;
  78                   break;
  79
  80                 case 'f':
  81                   *p++ = '\f';
  82                   break;
  83
  84                 case 'n':
  85                   *p++ = '\n';
  86                   break;
  87
  88                 case 'r':
  89                   *p++ = '\r';
  90                   break;
  91
  92                 case 't':
  93                   *p++ = '\t';
  94                   break;
  95
  96                 case 'v':
  97                   *p++ = '\v';
  98                   break;
  99                 }
 100               arg++;
 101               continue;
 102             }
 103
 104           /* This was not an escaped character, or escaping is not
 105              enabled.  */
 106           *p++ = *arg;
 107           arg++;
 108         }
 109
 110       *p = '\0';
 111       grub_xputs (unescaped);
 112       grub_free (unescaped);
 113
 114       /* If another argument follows, insert a space.  */
 115       if (i != argc - 1)
 116         grub_printf (" " );
 117     }
 118
 119   if (newline)
 120     grub_printf ("\n");
 121
 122   grub_refresh ();
 123
 124   return 0;
 125 }
 126
 127 static grub_extcmd_t cmd;
 128 \f
 129 GRUB_MOD_INIT(echo)
 130 {
 131   cmd = grub_register_extcmd ("echo", grub_cmd_echo,
 132                               GRUB_COMMAND_ACCEPT_DASH
 133                               | GRUB_COMMAND_OPTIONS_AT_START,
 134                               N_("[-e|-n] STRING"), N_("Display a line of text."),
 135                               options);
 136 }
 137
 138 GRUB_MOD_FINI(echo)
 139 {
 140   grub_unregister_extcmd (cmd);
 141 }