commands/help.c

   1 /* help.c - command to show a help text.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2005,2007,2008,2009  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/term.h>
  23 #include <grub/extcmd.h>
  24 #include <grub/i18n.h>
  25 #include <grub/mm.h>
  26 #include <grub/normal.h>
  27 #include <grub/charset.h>
  28
  29 static grub_err_t
  30 grub_cmd_help (grub_extcmd_t ext __attribute__ ((unused)), int argc,
  31                char **args)
  32 {
  33   int cnt = 0;
  34   char *currarg;
  35
  36   if (argc == 0)
  37     {
  38       grub_command_t cmd;
  39       FOR_COMMANDS(cmd)
  40       {
  41         if ((cmd->prio & GRUB_PRIO_LIST_FLAG_ACTIVE) &&
  42             (cmd->flags & GRUB_COMMAND_FLAG_CMDLINE))
  43           {
  44             struct grub_term_output *term;
  45             const char *summary_translated = _(cmd->summary);
  46             char *command_help;
  47             grub_uint32_t *unicode_command_help;
  48             grub_uint32_t *unicode_last_position;
  49
  50             command_help = grub_xasprintf ("%s %s", cmd->name, summary_translated);
  51             if (!command_help)
  52               break;
  53
  54             grub_utf8_to_ucs4_alloc (command_help, &unicode_command_help,
  55                                      &unicode_last_position);
  56
  57             FOR_ACTIVE_TERM_OUTPUTS(term)
  58             {
  59               unsigned stringwidth;
  60               grub_uint32_t *unicode_last_screen_position;
  61
  62               unicode_last_screen_position = unicode_command_help;
  63
  64               stringwidth = 0;
  65
  66               while (unicode_last_screen_position < unicode_last_position &&
  67                      stringwidth < ((grub_term_width (term) / 2) - 2))
  68                 {
  69                   struct grub_unicode_glyph glyph;
  70                   unicode_last_screen_position
  71                     += grub_unicode_aglomerate_comb (unicode_last_screen_position,
  72                                                      unicode_last_position
  73                                                      - unicode_last_screen_position,
  74                                                      &glyph);
  75
  76                   stringwidth
  77                     += grub_term_getcharwidth (term, &glyph);
  78                 }
  79
  80               grub_print_ucs4 (unicode_command_help,
  81                                unicode_last_screen_position, 0, 0, term);
  82               if (!(cnt % 2))
  83                 grub_print_spaces (term, grub_term_width (term) / 2
  84                                    - stringwidth);
  85             }
  86
  87             if (cnt % 2)
  88               grub_printf ("\n");
  89             cnt++;
  90
  91             grub_free (command_help);
  92             grub_free (unicode_command_help);
  93           }
  94       }
  95       if (!(cnt % 2))
  96         grub_printf ("\n");
  97     }
  98   else
  99     {
 100       int i;
 101       grub_command_t cmd;
 102
 103       for (i = 0; i < argc; i++)
 104         {
 105           currarg = args[i];
 106           FOR_COMMANDS(cmd)
 107           {
 108             if (cmd->prio & GRUB_PRIO_LIST_FLAG_ACTIVE)
 109               {
 110                 if (! grub_strncmp (cmd->name, currarg, grub_strlen (currarg)))
 111                   {
 112                     if (cnt++ > 0)
 113                       grub_printf ("\n\n");
 114
 115                     if (cmd->flags & GRUB_COMMAND_FLAG_EXTCMD)
 116                       grub_arg_show_help ((grub_extcmd_t) cmd->data);
 117                     else
 118                       grub_printf ("%s %s %s\n%s\n", _("Usage:"), cmd->name, _(cmd->summary),
 119                                    _(cmd->description));
 120                   }
 121               }
 122           }
 123         }
 124     }
 125
 126   return 0;
 127 }
 128
 129 static grub_extcmd_t cmd;
 130 \f
 131 GRUB_MOD_INIT(help)
 132 {
 133   cmd = grub_register_extcmd ("help", grub_cmd_help,
 134                               GRUB_COMMAND_FLAG_CMDLINE,
 135                               N_("[PATTERN ...]"),
 136                               N_("Show a help message."), 0);
 137 }
 138
 139 GRUB_MOD_FINI(help)
 140 {
 141   grub_unregister_extcmd (cmd);
 142 }