builtins/help.def

   1 This file is help.def, from which is created help.c.
   2 It implements the builtin "help" in Bash.
   3
   4 Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
   5
   6 This file is part of GNU Bash, the Bourne Again SHell.
   7
   8 Bash is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 1, or (at your option) any later
  11 version.
  12
  13 Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License along
  19 with Bash; see the file COPYING.  If not, write to the Free Software
  20 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 $PRODUCES help.c
  23
  24 $BUILTIN help
  25 $FUNCTION help_builtin
  26 $DEPENDS_ON HELP_BUILTIN
  27 $SHORT_DOC help [pattern ...]
  28 Display helpful information about builtin commands.  If PATTERN is
  29 specified, gives detailed help on all commands matching PATTERN,
  30 otherwise a list of the builtins is printed.
  31 $END
  32
  33 #include <config.h>
  34
  35 #if defined (HELP_BUILTIN)
  36 #include <stdio.h>
  37
  38 #if defined (HAVE_UNISTD_H)
  39 #  include <unistd.h>
  40 #endif
  41
  42 #include "../shell.h"
  43 #include "../builtins.h"
  44 #include "bashgetopt.h"
  45
  46 #include <glob/fnmatch.h>
  47 #include <glob/glob.h>
  48
  49 static void show_builtin_command_help ();
  50
  51 /* Print out a list of the known functions in the shell, and what they do.
  52    If LIST is supplied, print out the list which matches for each pattern
  53    specified. */
  54 int
  55 help_builtin (list)
  56      WORD_LIST *list;
  57 {
  58   register int i, j;
  59   char *pattern, *name;
  60   int plen, match_found;
  61
  62   if (list == 0)
  63     {
  64       show_shell_version (0);
  65       show_builtin_command_help ();
  66       return (EXECUTION_SUCCESS);
  67     }
  68
  69   /* Placeholder for future options. */
  70   reset_internal_getopt ();
  71   while ((i = internal_getopt (list, "")) != -1)
  72     {
  73       switch (i)
  74         {
  75         default:
  76           builtin_usage ();
  77           return (EX_USAGE);
  78         }
  79     }
  80   list = loptend;
  81
  82   /* We should consider making `help bash' do something. */
  83
  84   if (glob_pattern_p (list->word->word))
  85     {
  86       printf ("Shell commands matching keyword%s `", list->next ? "s" : "");
  87       print_word_list (list, ", ");
  88       printf ("'\n\n");
  89     }
  90
  91   for (match_found = 0, pattern = ""; list; list = list->next)
  92     {
  93       pattern = list->word->word;
  94       plen = strlen (pattern);
  95
  96       for (i = 0; name = shell_builtins[i].name; i++)
  97         {
  98           QUIT;
  99           if ((strncmp (pattern, name, plen) == 0) ||
 100               (fnmatch (pattern, name, 0) != FNM_NOMATCH))
 101             {
 102               printf ("%s: %s\n", name, shell_builtins[i].short_doc);
 103
 104               for (j = 0; shell_builtins[i].long_doc[j]; j++)
 105                 printf ("    %s\n", shell_builtins[i].long_doc[j]);
 106
 107               match_found++;
 108             }
 109         }
 110     }
 111
 112   if (match_found == 0)
 113     {
 114       builtin_error ("no help topics match `%s'.  Try `help help'.", pattern);
 115       return (EXECUTION_FAILURE);
 116     }
 117
 118   fflush (stdout);
 119   return (EXECUTION_SUCCESS);
 120 }
 121
 122 static void
 123 show_builtin_command_help ()
 124 {
 125   int i, j;
 126   char blurb[36];
 127
 128   printf (
 129 "These shell commands are defined internally.  Type `help' to see this list.\n\
 130 Type `help name' to find out more about the function `name'.\n\
 131 Use `info bash' to find out more about the shell in general.\n\
 132 \n\
 133 A star (*) next to a name means that the command is disabled.\n\
 134 \n");
 135
 136   for (i = 0; i < num_shell_builtins; i++)
 137     {
 138       QUIT;
 139       blurb[0] = (shell_builtins[i].flags & BUILTIN_ENABLED) ? ' ' : '*';
 140       strncpy (blurb + 1, shell_builtins[i].short_doc, 34);
 141       blurb[35] = '\0';
 142       printf ("%s", blurb);
 143
 144       if (i % 2)
 145         printf ("\n");
 146       else
 147         for (j = strlen (blurb); j < 35; j++)
 148           putc (' ', stdout);
 149     }
 150   if (i % 2)
 151     printf ("\n");
 152 }
 153 #endif /* HELP_BUILTIN */