1/*  Part of SWI-Prolog
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  1985-2002, University of Amsterdam
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(files,
   36        [ can_open_file/2,              % +Path, +Mode
   37          chdir/1                       % +Dir
   38        ]).

 can_open_file(+Path, +Mode)

Succeeds if the user has access to `File' in mode `Mode'. Fails silently if this is not the case. `Mode' is one of {read, write, both}. This used to be difficult. Since we have access_file/2 it is merely a Quintus compatibility predicate and should be in quintus.pl. We will leave it here for compatibility reasons.

deprecated

- Use access_file/2.

   51can_open_file(File, read) :-
   52    !,
   53    access_file(File, read).
   54can_open_file(File, write) :-
   55    !,
   56    (   exists_file(File)
   57    ->  access_file(File, write)
   58    ;   path_dir_name(File, Dir),
   59        access_file(Dir, write)
   60    ).
   61can_open_file(File, both) :-
   62    access_file(File, read),
   63    access_file(File, write).
   64
   65path_dir_name(File, Dir) :-
   66    file_base_name(File, Base),
   67    atom_concat(RawDir, Base, File),
   68    (   RawDir == ''
   69    ->  Dir = '.'
   70    ;   Dir = RawDir
   71    ).

 chdir(+Dir) is det

Change Working Directory.

deprecated

- Use using working_directory/2.

   79chdir(Dir) :-
   80    working_directory(_Old, Dir)