bash/builtins/type.def

This file is type.def, from which is created type.c.
It implements the builtin "type" in Bash.

Copyright (C) 1987, 1989, 1991, 1992 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

Bash is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 1, or (at your option) any later
version.

Bash is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with Bash; see the file COPYING.  If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

$PRODUCES type.c

$BUILTIN type
$FUNCTION type_builtin
$SHORT_DOC type [-apt] name [name ...]
For each NAME, indicate how it would be interpreted if used as a
command name.

If the -t option is used, `type' outputs a single word which is one of
`alias', `keyword', `function', `builtin', `file' or `', if NAME is an
alias, shell reserved word, shell function, shell builtin, disk file,
or unfound, respectively.

If the -p flag is used, `type' either returns the name of the disk
file that would be executed, or nothing if `type -t NAME' would not
return `file'.

If the -a flag is used, `type' displays all of the places that contain
an executable named `file'.  This includes aliases and functions, if
and only if the -p flag is not also used.
$END

#include <config.h>

#include "../bashtypes.h"
#include "../posixstat.h"

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#include <stdio.h>
#include "../bashansi.h"

#include "../shell.h"
#include "../findcmd.h"
#include "../hashcmd.h"

#if defined (ALIAS)
#include "../alias.h"
#endif /* ALIAS */

#include "common.h"

extern int find_reserved_word ();

/* For each word in LIST, find out what the shell is going to do with
   it as a simple command. i.e., which file would this shell use to
   execve, or if it is a builtin command, or an alias.  Possible flag
   arguments:
	-type		Returns the "type" of the object, one of
			`alias', `keyword', `function', `builtin',
			or `file'.

	-path		Returns the pathname of the file if -type is
			a file.

	-all		Returns all occurrences of words, whether they
			be a filename in the path, alias, function,
			or builtin.
   Order of evaluation:
	alias
	keyword
	function
	builtin
	file
 */
int
type_builtin (list)
     WORD_LIST *list;
{
  int path_only, type_only, all, verbose;
  int successful_finds;

  if (list == 0)
    return (EXECUTION_SUCCESS);

  path_only = type_only = all = 0;
  successful_finds = 0;

  while (list && *(list->word->word) == '-')
    {
      char *flag = &(list->word->word[1]);

      if (flag[0] == 't' && (!flag[1] || strcmp (flag + 1, "ype") == 0))
	{
	  type_only = 1;
	  path_only = 0;
	}
      else if (flag[0] == 'p' && (!flag[1] || strcmp (flag + 1, "ath") == 0))
	{
	  path_only = 1;
	  type_only = 0;
	}
      else if (flag[0] == 'a' && (!flag[1] || strcmp (flag + 1, "ll") == 0))
	{
	  all = 1;
	}
      else
	{
	  bad_option (flag);
	  builtin_usage ();
	  return (EX_USAGE);
	}
      list = list->next;
    }

  if (type_only)
    verbose = 1;
  else if (path_only == 0)
    verbose = 2;
  else if (path_only)
    verbose = 3;
  else
    verbose = 0;

  while (list)
    {
      int found;

      found = describe_command (list->word->word, verbose, all);

      if (!found && !path_only && !type_only)
	builtin_error ("%s: not found", list->word->word);

      successful_finds += found;
      list = list->next;
    }

  fflush (stdout);

  if (successful_finds != 0)
    return (EXECUTION_SUCCESS);
  else
    return (EXECUTION_FAILURE);
}

/*
 * Describe COMMAND as required by the type builtin.
 *
 * If VERBOSE == 0, don't print anything
 * If VERBOSE == 1, print short description as for `type -t'
 * If VERBOSE == 2, print long description as for `type' and `command -V'
 * If VERBOSE == 3, print path name only for disk files
 * If VERBOSE == 4, print string used to invoke COMMAND, for `command -v'
 *
 * ALL says whether or not to look for all occurrences of COMMAND, or
 * return after finding it once.
 */
int
describe_command (command, verbose, all)
     char *command;
     int verbose, all;
{
  int found, i, found_file;
  char *full_path;
  SHELL_VAR *func;
#if defined (ALIAS)
  alias_t *alias;
#endif

  found = found_file = 0;
  full_path = (char *)NULL;

#if defined (ALIAS)
  /* Command is an alias? */
  alias = find_alias (command);

  if (alias)
    {
      if (verbose == 1)
	puts ("alias");
      else if (verbose == 2)
	printf ("%s is aliased to `%s'\n", command, alias->value);
      else if (verbose == 4)
	{
	  char *x = single_quote (alias->value);
	  printf ("alias %s=%s\n", command, x);
	  free (x);
	}

      found = 1;

      if (!all)
	return (1);
    }
#endif /* ALIAS */

  /* Command is a shell reserved word? */
  i = find_reserved_word (command);
  if (i >= 0)
    {
      if (verbose == 1)
	puts ("keyword");
      else if (verbose == 2)
	printf ("%s is a shell keyword\n", command);
      else if (verbose == 4)
	printf ("%s\n", command);

      found = 1;

      if (!all)
	return (1);
    }

  /* Command is a function? */
  func = find_function (command);

  if (func)
    {
      if (verbose == 1)
	puts ("function");
      else if (verbose == 2)
	{
#define PRETTY_PRINT_FUNC 1
	  char *result;

	  printf ("%s is a function\n", command);

	  /* We're blowing away THE_PRINTED_COMMAND here... */

	  result = named_function_string (command,
					  (COMMAND *) function_cell (func),
					  PRETTY_PRINT_FUNC);
	  printf ("%s\n", result);
#undef PRETTY_PRINT_FUNC
	}
      else if (verbose == 4)
	printf ("%s\n", command);

      found = 1;

      if (!all)
	return (1);
    }

  /* Command is a builtin? */
  if (find_shell_builtin (command))
    {
      if (verbose == 1)
	puts ("builtin");
      else if (verbose == 2)
	printf ("%s is a shell builtin\n", command);
      else if (verbose == 4)
	printf ("%s\n", command);

      found = 1;

      if (!all)
	return (1);
    }

  /* Command is a disk file? */
  /* If the command name given is already an absolute command, just
     check to see if it is executable. */
  if (absolute_program (command))
    {
      int f = file_status (command);
      if (f & FS_EXECABLE)
        {
	  if (verbose == 1)
	    puts ("file");
	  else if (verbose == 2)
	    printf ("%s is %s\n", command, command);
	  else if (verbose == 3 || verbose == 4)
	    printf ("%s\n", command);

	  /* There's no use looking in the hash table or in $PATH,
	     because they're not consulted when an absolute program
	     name is supplied. */
	  return (1);
        }
    }

  /* If the user isn't doing "-all", then we might care about
     whether the file is present in our hash table. */
  if (!all)
    {
      if ((full_path = find_hashed_filename (command)) != (char *)NULL)
	{
	  if (verbose == 1)
	    puts ("file");
	  else if (verbose == 2)
	    printf ("%s is hashed (%s)\n", command, full_path);
	  else if (verbose == 3 || verbose == 4)
	    printf ("%s\n", full_path);

	  free (full_path);
	  return (1);
	}
    }

  /* Now search through $PATH. */
  while (1)
    {
      if (!all)
	full_path = find_user_command (command);
      else
	full_path =
	  user_command_matches (command, FS_EXEC_ONLY, found_file);
	  /* XXX - should that be FS_EXEC_PREFERRED? */

      if (!full_path)
	break;

      found_file++;
      found = 1;

      if (verbose == 1)
	puts ("file");
      else if (verbose == 2)
	printf ("%s is %s\n", command, full_path);
      else if (verbose == 3 || verbose == 4)
	printf ("%s\n", full_path);

      free (full_path);
      full_path = (char *)NULL;

      if (!all)
	break;
    }

  return (found);
}