/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@cs.vu.nl WWW: http://www.swi-prolog.org Copyright (C): 2002-2015, University of Amsterdam Vu University Amsterdam This program 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 2 of the License, or (at your option) any later version. This program 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 Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA As a special exception, if you link this library with other files, compiled with a Free Software compiler, to produce an executable, this library does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ :- module(files_ex, [ set_time_file/3, % +File, -OldTimes, +NewTimes link_file/3, % +OldPath, +NewPath, +Type relative_file_name/3, % +AbsPath, +RelTo, -RelPath directory_file_path/3, % +Dir, +File, -Path copy_file/2, % +From, +To make_directory_path/1, % +Directory copy_directory/2, % +Source, +Destination delete_directory_and_contents/1, % +Dir delete_directory_contents/1 % +Dir ]). /** Extended operations on files This module provides additional operations on files. This covers both more obscure and possible non-portable low-level operations and high-level utilities. Using these Prolog primitives is typically to be preferred over using operating system primitives through shell/1 or process_create/3 because (1) there are no potential file name quoting issues, (2) there is no dependency on operating system commands and (3) using the implementations from this library is usually faster. */ :- use_foreign_library(foreign(files), install_files). %% set_time_file(+File, -OldTimes, +NewTimes) is det. % % Query and set POSIX time attributes of a file. Both OldTimes and % NewTimes are lists of option-terms. Times are represented in % SWI-Prolog's standard floating point numbers. New times may be % specified as =now= to indicate the current time. Defined options % are: % % * access(Time) % Describes the time of last access of the file. This value % can be read and written. % % * modified(Time) % Describes the time the contents of the file was last % modified. This value can be read and written. % % * changed(Time) % Describes the time the file-structure itself was changed by % adding (link()) or removing (unlink()) names. % % Below are some example queries. The first retrieves the % access-time, while the second sets the last-modified time to the % current time. % % == % ?- set_time_file(foo, [access(Access)], []). % ?- set_time_file(foo, [], [modified(now)]). % == %% link_file(+OldPath, +NewPath, +Type) is det. % % Create a link in the filesystem from NewPath to OldPath. Type % defines the type of link and is one of =hard= or =symbolic=. % % With some limitations, these functions also work on Windows. % First of all, the unerlying filesystem must support links. This % requires NTFS. Second, symbolic links are only supported in % Vista and later. % % @error domain_error(link_type, Type) if the requested link-type % is unknown or not supported on the target OS. %% relative_file_name(+Path:atom, +RelTo:atom, -RelPath:atom) is det. % % True when RelPath is Path, relative to RelTo. Path and RelTo are % first handed to absolute_file_name/2, which makes the absolute % *and* canonical. Below is an example: % % == % ?- relative_file_name('/home/janw/nice', % '/home/janw/deep/dir/file', Path). % Path = '../../nice'. % == % % @param All paths must be in canonical POSIX notation, i.e., % using / to separate segments in the path. See % prolog_to_os_filename/2. % @bug This predicate is defined as a _syntactical_ operation. relative_file_name(Path, RelTo, RelPath) :- absolute_file_name(Path, AbsPath), absolute_file_name(RelTo, AbsRelTo), atomic_list_concat(PL, /, AbsPath), atomic_list_concat(RL, /, AbsRelTo), delete_common_prefix(PL, RL, PL1, PL2), to_dot_dot(PL2, DotDot, PL1), atomic_list_concat(DotDot, /, RelPath). delete_common_prefix([H|T01], [H|T02], T1, T2) :- !, delete_common_prefix(T01, T02, T1, T2). delete_common_prefix(T1, T2, T1, T2). to_dot_dot([], Tail, Tail). to_dot_dot([_], Tail, Tail) :- !. to_dot_dot([_|T0], ['..'|T], Tail) :- to_dot_dot(T0, T, Tail). %% directory_file_path(+Directory, +File, -Path) is det. %% directory_file_path(?Directory, ?File, +Path) is det. % % True when Path is the full path-name for File in Dir. This is % comparable to atom_concat(Directory, File, Path), but it ensures % there is exactly one / between the two parts. Notes: % % * In mode (+,+,-), if File is given and absolute, Path % is unified to File. % * Mode (-,-,+) uses file_directory_name/2 and file_base_name/2 directory_file_path(Dir, File, Path) :- nonvar(Dir), nonvar(File), !, ( ( is_absolute_file_name(File) ; Dir == '.' ) -> Path = File ; sub_atom(Dir, _, _, 0, /) -> atom_concat(Dir, File, Path) ; atomic_list_concat([Dir, /, File], Path) ). directory_file_path(Dir, File, Path) :- nonvar(Path), !, ( nonvar(Dir) -> ( sub_atom(Dir, _, _, 0, /) -> atom_concat(Dir, File, Path) ; atom_concat(Dir, /, TheDir), atom_concat(TheDir, File, Path) ) ; nonvar(File) -> atom_concat(Dir, File, Path) ; file_directory_name(Path, Dir), file_base_name(Path, File) ). directory_file_path(_, _, _) :- throw(error(instantiation_error(_), _)). %% copy_file(From, To) is det. % % Copy a file into a new file or directory. The data is copied as % binary data. copy_file(From, To) :- destination_file(To, From, Dest), setup_call_cleanup(open(Dest, write, Out, [type(binary)]), copy_from(From, Out), close(Out)). copy_from(File, Stream) :- setup_call_cleanup( open(File, read, In, [type(binary)]), copy_stream_data(In, Stream), close(In)). destination_file(Dir, File, Dest) :- exists_directory(Dir), !, file_base_name(File, Base), directory_file_path(Dir, Base, Dest). destination_file(Dest, _, Dest). %% make_directory_path(+Dir) is det. % % Create Dir and all required components (like mkdir -p). Can % raise various file-specific exceptions. make_directory_path(Dir) :- make_directory_path_2(Dir), !. make_directory_path(Dir) :- permission_error(create, directory, Dir). make_directory_path_2(Dir) :- exists_directory(Dir), !. make_directory_path_2(Dir) :- Dir \== (/), !, file_directory_name(Dir, Parent), make_directory_path_2(Parent), make_directory(Dir). %% copy_directory(+From, +To) is det. % % Copy the contents of the directory From to To (recursively). If % To is the name of an existing directory, the _contents_ of From % are copied into To. I.e., no subdirectory using the basename of % From is created. copy_directory(From, To) :- ( exists_directory(To) -> true ; make_directory(To) ), directory_files(From, Entries), maplist(copy_directory_content(From, To), Entries). copy_directory_content(_From, _To, Special) :- special(Special), !. copy_directory_content(From, To, Entry) :- directory_file_path(From, Entry, Source), directory_file_path(To, Entry, Dest), ( exists_directory(Source) -> copy_directory(Source, Dest) ; copy_file(Source, Dest) ). special(.). special(..). %% delete_directory_and_contents(+Dir) is det. % % Recursively remove the directory Dir and its contents. If Dir is % a symbolic link or symbolic links inside Dir are encountered, % the links are removed rather than their content. Use with care! delete_directory_and_contents(Dir) :- read_link(Dir, _, _), !, delete_file(Dir). delete_directory_and_contents(Dir) :- directory_files(Dir, Files), maplist(delete_directory_contents(Dir), Files), delete_directory(Dir). delete_directory_contents(_, Entry) :- special(Entry), !. delete_directory_contents(Dir, Entry) :- directory_file_path(Dir, Entry, Delete), ( exists_directory(Delete) -> delete_directory_and_contents(Delete) ; delete_file(Delete) ). %% delete_directory_contents(+Dir) is det. % % Remove all content from directory Dir, without removing Dir % itself. Similar to delete_directory_and_contents/2, if symbolic % links are encountered in Dir, the links are removed rather than % their content. delete_directory_contents(Dir) :- directory_files(Dir, Files), maplist(delete_directory_contents(Dir), Files).