builtins/type.def

   1 This file is type.def, from which is created type.c.
   2 It implements the builtin "type" in Bash.
   3
   4 Copyright (C) 1987-2002 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 type.c
  23
  24 $BUILTIN type
  25 $FUNCTION type_builtin
  26 $SHORT_DOC type [-afptP] name [name ...]
  27 For each NAME, indicate how it would be interpreted if used as a
  28 command name.
  29
  30 If the -t option is used, `type' outputs a single word which is one of
  31 `alias', `keyword', `function', `builtin', `file' or `', if NAME is an
  32 alias, shell reserved word, shell function, shell builtin, disk file,
  33 or unfound, respectively.
  34
  35 If the -p flag is used, `type' either returns the name of the disk
  36 file that would be executed, or nothing if `type -t NAME' would not
  37 return `file'.
  38
  39 If the -a flag is used, `type' displays all of the places that contain
  40 an executable named `file'.  This includes aliases, builtins, and
  41 functions, if and only if the -p flag is not also used.
  42
  43 The -f flag suppresses shell function lookup.
  44
  45 The -P flag forces a PATH search for each NAME, even if it is an alias,
  46 builtin, or function, and returns the name of the disk file that would
  47 be executed.
  48 $END
  49
  50 #include <config.h>
  51
  52 #include "../bashtypes.h"
  53 #include "posixstat.h"
  54
  55 #if defined (HAVE_UNISTD_H)
  56 #  include <unistd.h>
  57 #endif
  58
  59 #include <stdio.h>
  60 #include "../bashansi.h"
  61
  62 #include "../shell.h"
  63 #include "../findcmd.h"
  64 #include "../hashcmd.h"
  65
  66 #if defined (ALIAS)
  67 #include "../alias.h"
  68 #endif /* ALIAS */
  69
  70 #include "common.h"
  71 #include "bashgetopt.h"
  72
  73 extern int find_reserved_word __P((char *));
  74
  75 extern char *this_command_name;
  76
  77 /* For each word in LIST, find out what the shell is going to do with
  78    it as a simple command. i.e., which file would this shell use to
  79    execve, or if it is a builtin command, or an alias.  Possible flag
  80    arguments:
  81         -t              Returns the "type" of the object, one of
  82                         `alias', `keyword', `function', `builtin',
  83                         or `file'.
  84
  85         -p              Returns the pathname of the file if -type is
  86                         a file.
  87
  88         -a              Returns all occurrences of words, whether they
  89                         be a filename in the path, alias, function,
  90                         or builtin.
  91
  92         -f              Suppress shell function lookup, like `command'.
  93
  94         -P              Force a path search even in the presence of other
  95                         definitions.
  96
  97    Order of evaluation:
  98         alias
  99         keyword
 100         function
 101         builtin
 102         file
 103  */
 104
 105 int
 106 type_builtin (list)
 107      WORD_LIST *list;
 108 {
 109   int dflags, successful_finds, opt;
 110   WORD_LIST *this;
 111
 112   if (list == 0)
 113     return (EXECUTION_SUCCESS);
 114
 115   dflags = CDESC_SHORTDESC;     /* default */
 116   successful_finds = 0;
 117
 118   /* Handle the obsolescent `-type', `-path', and `-all' by prescanning
 119      the arguments and converting those options to the form that
 120      internal_getopt recognizes. Converts `--type', `--path', and `--all'
 121      also. THIS SHOULD REALLY GO AWAY. */
 122   for (this = list; this && this->word->word[0] == '-'; this = this->next)
 123     {
 124       char *flag = &(this->word->word[1]);
 125
 126       if (STREQ (flag, "type") || STREQ (flag, "-type"))
 127         {
 128           this->word->word[1] = 't';
 129           this->word->word[2] = '\0';
 130         }
 131       else if (STREQ (flag, "path") || STREQ (flag, "-path"))
 132         {
 133           this->word->word[1] = 'p';
 134           this->word->word[2] = '\0';
 135         }
 136       else if (STREQ (flag, "all") || STREQ (flag, "-all"))
 137         {
 138           this->word->word[1] = 'a';
 139           this->word->word[2] = '\0';
 140         }
 141     }
 142
 143   reset_internal_getopt ();
 144   while ((opt = internal_getopt (list, "afptP")) != -1)
 145     {
 146       switch (opt)
 147         {
 148         case 'a':
 149           dflags |= CDESC_ALL;
 150           break;
 151         case 'f':
 152           dflags |= CDESC_NOFUNCS;
 153           break;
 154         case 'p':
 155           dflags |= CDESC_PATH_ONLY;
 156           dflags &= ~(CDESC_TYPE|CDESC_SHORTDESC);
 157           break;
 158         case 't':
 159           dflags |= CDESC_TYPE;
 160           dflags &= ~(CDESC_PATH_ONLY|CDESC_SHORTDESC);
 161           break;
 162         case 'P':       /* shorthand for type -ap */
 163           dflags |= (CDESC_PATH_ONLY|CDESC_FORCE_PATH);
 164           dflags &= ~(CDESC_TYPE|CDESC_SHORTDESC);
 165           break;
 166         default:
 167           builtin_usage ();
 168           return (EX_USAGE);
 169         }
 170     }
 171   list = loptend;
 172
 173   while (list)
 174     {
 175       int found;
 176
 177       found = describe_command (list->word->word, dflags);
 178
 179       if (!found && (dflags & (CDESC_PATH_ONLY|CDESC_TYPE)) == 0)
 180         sh_notfound (list->word->word);
 181
 182       successful_finds += found;
 183       list = list->next;
 184     }
 185
 186   fflush (stdout);
 187
 188   return ((successful_finds != 0) ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
 189 }
 190
 191 /*
 192  * Describe COMMAND as required by the type and command builtins.
 193  *
 194  * Behavior is controlled by DFLAGS.  Flag values are
 195  *      CDESC_ALL       print all descriptions of a command
 196  *      CDESC_SHORTDESC print the description for type and command -V
 197  *      CDESC_REUSABLE  print in a format that may be reused as input
 198  *      CDESC_TYPE      print the type for type -t
 199  *      CDESC_PATH_ONLY print the path for type -p
 200  *      CDESC_FORCE_PATH        force a path search for type -P
 201  *      CDESC_NOFUNCS   skip function lookup for type -f
 202  *
 203  * CDESC_ALL says whether or not to look for all occurrences of COMMAND, or
 204  * return after finding it once.
 205  */
 206 int
 207 describe_command (command, dflags)
 208      char *command;
 209      int dflags;
 210 {
 211   int found, i, found_file, f, all;
 212   char *full_path, *x;
 213   SHELL_VAR *func;
 214 #if defined (ALIAS)
 215   alias_t *alias;
 216 #endif
 217
 218   all = (dflags & CDESC_ALL) != 0;
 219   found = found_file = 0;
 220   full_path = (char *)NULL;
 221
 222 #if defined (ALIAS)
 223   /* Command is an alias? */
 224   if (((dflags & CDESC_FORCE_PATH) == 0) && (alias = find_alias (command)))
 225     {
 226       if (dflags & CDESC_TYPE)
 227         puts ("alias");
 228       else if (dflags & CDESC_SHORTDESC)
 229         printf ("%s is aliased to `%s'\n", command, alias->value);
 230       else if (dflags & CDESC_REUSABLE)
 231         {
 232           x = sh_single_quote (alias->value);
 233           printf ("alias %s=%s\n", command, x);
 234           free (x);
 235         }
 236
 237       found = 1;
 238
 239       if (all == 0)
 240         return (1);
 241     }
 242 #endif /* ALIAS */
 243
 244   /* Command is a shell reserved word? */
 245   if (((dflags & CDESC_FORCE_PATH) == 0) && (i = find_reserved_word (command)) >= 0)
 246     {
 247       if (dflags & CDESC_TYPE)
 248         puts ("keyword");
 249       else if (dflags & CDESC_SHORTDESC)
 250         printf ("%s is a shell keyword\n", command);
 251       else if (dflags & CDESC_REUSABLE)
 252         printf ("%s\n", command);
 253
 254       found = 1;
 255
 256       if (all == 0)
 257         return (1);
 258     }
 259
 260   /* Command is a function? */
 261   if (((dflags & (CDESC_FORCE_PATH|CDESC_NOFUNCS)) == 0) && (func = find_function (command)))
 262     {
 263       if (dflags & CDESC_TYPE)
 264         puts ("function");
 265       else if (dflags & CDESC_SHORTDESC)
 266         {
 267 #define PRETTY_PRINT_FUNC 1
 268           char *result;
 269
 270           printf ("%s is a function\n", command);
 271
 272           /* We're blowing away THE_PRINTED_COMMAND here... */
 273
 274           result = named_function_string (command,
 275                                           (COMMAND *) function_cell (func),
 276                                           PRETTY_PRINT_FUNC);
 277           printf ("%s\n", result);
 278 #undef PRETTY_PRINT_FUNC
 279         }
 280       else if (dflags & CDESC_REUSABLE)
 281         printf ("%s\n", command);
 282
 283       found = 1;
 284
 285       if (all == 0)
 286         return (1);
 287     }
 288
 289   /* Command is a builtin? */
 290   if (((dflags & CDESC_FORCE_PATH) == 0) && find_shell_builtin (command))
 291     {
 292       if (dflags & CDESC_TYPE)
 293         puts ("builtin");
 294       else if (dflags & CDESC_SHORTDESC)
 295         printf ("%s is a shell builtin\n", command);
 296       else if (dflags & CDESC_REUSABLE)
 297         printf ("%s\n", command);
 298
 299       found = 1;
 300
 301       if (all == 0)
 302         return (1);
 303     }
 304
 305   /* Command is a disk file? */
 306   /* If the command name given is already an absolute command, just
 307      check to see if it is executable. */
 308   if (absolute_program (command))
 309     {
 310       f = file_status (command);
 311       if (f & FS_EXECABLE)
 312         {
 313           if (dflags & CDESC_TYPE)
 314             puts ("file");
 315           else if (dflags & CDESC_SHORTDESC)
 316             printf ("%s is %s\n", command, command);
 317           else if (dflags & (CDESC_REUSABLE|CDESC_PATH_ONLY))
 318             printf ("%s\n", command);
 319
 320           /* There's no use looking in the hash table or in $PATH,
 321              because they're not consulted when an absolute program
 322              name is supplied. */
 323           return (1);
 324         }
 325     }
 326
 327   /* If the user isn't doing "-a", then we might care about
 328      whether the file is present in our hash table. */
 329   if (all == 0 || (dflags & CDESC_FORCE_PATH))
 330     {
 331       if (full_path = phash_search (command))
 332         {
 333           if (dflags & CDESC_TYPE)
 334             puts ("file");
 335           else if (dflags & CDESC_SHORTDESC)
 336             printf ("%s is hashed (%s)\n", command, full_path);
 337           else if (dflags & (CDESC_REUSABLE|CDESC_PATH_ONLY))
 338             printf ("%s\n", full_path);
 339
 340           free (full_path);
 341           return (1);
 342         }
 343     }
 344
 345   /* Now search through $PATH. */
 346   while (1)
 347     {
 348       if (all == 0)
 349         full_path = find_user_command (command);
 350       else
 351         full_path =
 352           user_command_matches (command, FS_EXEC_ONLY, found_file);
 353           /* XXX - should that be FS_EXEC_PREFERRED? */
 354
 355       if (!full_path)
 356         break;
 357
 358       /* If we found the command as itself by looking through $PATH, it
 359          probably doesn't exist.  Check whether or not the command is an
 360          executable file.  If it's not, don't report a match. */
 361       if (STREQ (full_path, command))
 362         {
 363           f = file_status (full_path);
 364           if ((f & FS_EXECABLE) == 0)
 365             {
 366               free (full_path);
 367               full_path = (char *)NULL;
 368               if (all == 0)
 369                 break;
 370             }
 371           else if (dflags & (CDESC_REUSABLE|CDESC_PATH_ONLY|CDESC_SHORTDESC))
 372             full_path = sh_makepath ((char *)NULL, full_path, MP_DOCWD);
 373         }
 374
 375       found_file++;
 376       found = 1;
 377
 378       if (dflags & CDESC_TYPE)
 379         puts ("file");
 380       else if (dflags & CDESC_SHORTDESC)
 381         printf ("%s is %s\n", command, full_path);
 382       else if (dflags & (CDESC_REUSABLE|CDESC_PATH_ONLY))
 383         printf ("%s\n", full_path);
 384
 385       free (full_path);
 386       full_path = (char *)NULL;
 387
 388       if (all == 0)
 389         break;
 390     }
 391
 392   return (found);
 393 }