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) 1987-2003 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 <errno.h>
  48
  49 #include <filecntl.h>
  50
  51 #include "../bashintl.h"
  52
  53 #include "../shell.h"
  54 #include "../builtins.h"
  55 #include "../pathexp.h"
  56 #include "common.h"
  57 #include "bashgetopt.h"
  58
  59 #include <glob/strmatch.h>
  60 #include <glob/glob.h>
  61
  62 #ifndef errno
  63 extern int errno;
  64 #endif
  65
  66 static void show_builtin_command_help __P((void));
  67 static void show_longdoc __P((int));
  68
  69 /* Print out a list of the known functions in the shell, and what they do.
  70    If LIST is supplied, print out the list which matches for each pattern
  71    specified. */
  72 int
  73 help_builtin (list)
  74      WORD_LIST *list;
  75 {
  76   register int i;
  77   char *pattern, *name;
  78   int plen, match_found, sflag;
  79
  80   sflag = 0;
  81   reset_internal_getopt ();
  82   while ((i = internal_getopt (list, "s")) != -1)
  83     {
  84       switch (i)
  85         {
  86         case 's':
  87           sflag = 1;
  88           break;
  89         default:
  90           builtin_usage ();
  91           return (EX_USAGE);
  92         }
  93     }
  94   list = loptend;
  95
  96   if (list == 0)
  97     {
  98       show_shell_version (0);
  99       show_builtin_command_help ();
 100       return (EXECUTION_SUCCESS);
 101     }
 102
 103   /* We should consider making `help bash' do something. */
 104
 105   if (glob_pattern_p (list->word->word))
 106     {
 107       if (list->next)
 108         printf (_("Shell commands matching keywords `"));
 109       else
 110         printf (_("Shell commands matching keyword `"));
 111       print_word_list (list, ", ");
 112       printf ("'\n\n");
 113     }
 114
 115   for (match_found = 0, pattern = ""; list; list = list->next)
 116     {
 117       pattern = list->word->word;
 118       plen = strlen (pattern);
 119
 120       for (i = 0; name = shell_builtins[i].name; i++)
 121         {
 122           QUIT;
 123           if ((strncmp (pattern, name, plen) == 0) ||
 124               (strmatch (pattern, name, FNMATCH_EXTFLAG) != FNM_NOMATCH))
 125             {
 126               printf ("%s: %s\n", name, shell_builtins[i].short_doc);
 127
 128               if (sflag == 0)
 129                 show_longdoc (i);
 130
 131               match_found++;
 132             }
 133         }
 134     }
 135
 136   if (match_found == 0)
 137     {
 138       builtin_error (_("no help topics match `%s'.  Try `help help' or `man -k %s' or `info %s'."), pattern, pattern, pattern);
 139       return (EXECUTION_FAILURE);
 140     }
 141
 142   fflush (stdout);
 143   return (EXECUTION_SUCCESS);
 144 }
 145
 146 /* By convention, enforced by mkbuiltins.c, if separate help files are being
 147    used, the long_doc array contains one string -- the full pathname of the
 148    help file for this builtin.  */
 149 static void
 150 show_longdoc (i)
 151      int i;
 152 {
 153   register int j;
 154   char * const *doc;
 155   int fd;
 156
 157   doc = shell_builtins[i].long_doc;
 158
 159   if (doc && doc[0] && *doc[0] == '/' && doc[1] == (char *)NULL)
 160     {
 161       fd = open (doc[0], O_RDONLY);
 162       if (fd == -1)
 163         {
 164           builtin_error (_("%s: cannot open: %s"), doc[0], strerror (errno));
 165           return;
 166         }
 167       zcatfd (fd, 1, doc[0]);
 168       close (fd);
 169     }
 170   else
 171     for (j = 0; doc[j]; j++)
 172       printf ("%*s%s\n", BASE_INDENT, " ", _(doc[j]));
 173 }
 174
 175 static void
 176 show_builtin_command_help ()
 177 {
 178   int i, j;
 179   char blurb[36];
 180
 181   printf (
 182 _("These shell commands are defined internally.  Type `help' to see this list.\n\
 183 Type `help name' to find out more about the function `name'.\n\
 184 Use `info bash' to find out more about the shell in general.\n\
 185 Use `man -k' or `info' to find out more about commands not in this list.\n\
 186 \n\
 187 A star (*) next to a name means that the command is disabled.\n\
 188 \n"));
 189
 190   for (i = 0; i < num_shell_builtins; i++)
 191     {
 192       QUIT;
 193       blurb[0] = (shell_builtins[i].flags & BUILTIN_ENABLED) ? ' ' : '*';
 194       strncpy (blurb + 1, shell_builtins[i].short_doc, 34);
 195       blurb[35] = '\0';
 196       printf ("%s", blurb);
 197
 198       if (i % 2)
 199         printf ("\n");
 200       else
 201         for (j = strlen (blurb); j < 35; j++)
 202           putc (' ', stdout);
 203     }
 204   if (i % 2)
 205     printf ("\n");
 206 }
 207 #endif /* HELP_BUILTIN */