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 2, 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, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
  21
  22 $PRODUCES help.c
  23
  24 $BUILTIN help
  25 $FUNCTION help_builtin
  26 $DEPENDS_ON HELP_BUILTIN
  27 $SHORT_DOC help [-s] [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.  The -s option
  31 restricts the output for each builtin command matching PATTERN to
  32 a short usage synopsis.
  33 $END
  34
  35 #include <config.h>
  36
  37 #if defined (HELP_BUILTIN)
  38 #include <stdio.h>
  39
  40 #if defined (HAVE_UNISTD_H)
  41 #  ifdef _MINIX
  42 #    include <sys/types.h>
  43 #  endif
  44 #  include <unistd.h>
  45 #endif
  46
  47 #include "../shell.h"
  48 #include "../builtins.h"
  49 #include "../pathexp.h"
  50 #include "bashgetopt.h"
  51
  52 #include <glob/fnmatch.h>
  53 #include <glob/glob.h>
  54
  55 extern void builtin_error ();
  56 extern void builtin_usage ();
  57
  58 static  void show_builtin_command_help ();
  59
  60 /* Print out a list of the known functions in the shell, and what they do.
  61    If LIST is supplied, print out the list which matches for each pattern
  62    specified. */
  63 int
  64 help_builtin (list)
  65      WORD_LIST *list;
  66 {
  67   register int i, j;
  68   char *pattern, *name;
  69   int plen, match_found, sflag;
  70
  71   sflag = 0;
  72   reset_internal_getopt ();
  73   while ((i = internal_getopt (list, "s")) != -1)
  74     {
  75       switch (i)
  76         {
  77         case 's':
  78           sflag = 1;
  79           break;
  80         default:
  81           builtin_usage ();
  82           return (EX_USAGE);
  83         }
  84     }
  85   list = loptend;
  86
  87   if (list == 0)
  88     {
  89       show_shell_version (0);
  90       show_builtin_command_help ();
  91       return (EXECUTION_SUCCESS);
  92     }
  93
  94   /* We should consider making `help bash' do something. */
  95
  96   if (glob_pattern_p (list->word->word))
  97     {
  98       printf ("Shell commands matching keyword%s `", list->next ? "s" : "");
  99       print_word_list (list, ", ");
 100       printf ("'\n\n");
 101     }
 102
 103   for (match_found = 0, pattern = ""; list; list = list->next)
 104     {
 105       pattern = list->word->word;
 106       plen = strlen (pattern);
 107
 108       for (i = 0; name = shell_builtins[i].name; i++)
 109         {
 110           QUIT;
 111           if ((strncmp (pattern, name, plen) == 0) ||
 112               (fnmatch (pattern, name, FNMATCH_EXTFLAG) != FNM_NOMATCH))
 113             {
 114               printf ("%s: %s\n", name, shell_builtins[i].short_doc);
 115
 116               if (sflag == 0)
 117                 for (j = 0; shell_builtins[i].long_doc[j]; j++)
 118                   printf ("    %s\n", shell_builtins[i].long_doc[j]);
 119
 120               match_found++;
 121             }
 122         }
 123     }
 124
 125   if (match_found == 0)
 126     {
 127       builtin_error ("no help topics match `%s'.  Try `help help'.", pattern);
 128       return (EXECUTION_FAILURE);
 129     }
 130
 131   fflush (stdout);
 132   return (EXECUTION_SUCCESS);
 133 }
 134
 135 static void
 136 show_builtin_command_help ()
 137 {
 138   int i, j;
 139   char blurb[36];
 140
 141   printf (
 142 "These shell commands are defined internally.  Type `help' to see this list.\n\
 143 Type `help name' to find out more about the function `name'.\n\
 144 Use `info bash' to find out more about the shell in general.\n\
 145 \n\
 146 A star (*) next to a name means that the command is disabled.\n\
 147 \n");
 148
 149   for (i = 0; i < num_shell_builtins; i++)
 150     {
 151       QUIT;
 152       blurb[0] = (shell_builtins[i].flags & BUILTIN_ENABLED) ? ' ' : '*';
 153       strncpy (blurb + 1, shell_builtins[i].short_doc, 34);
 154       blurb[35] = '\0';
 155       printf ("%s", blurb);
 156
 157       if (i % 2)
 158         printf ("\n");
 159       else
 160         for (j = strlen (blurb); j < 35; j++)
 161           putc (' ', stdout);
 162     }
 163   if (i % 2)
 164     printf ("\n");
 165 }
 166 #endif /* HELP_BUILTIN */