/************************************************************************* * * * YAP Prolog * * * * Yap Prolog was developed at NCCUP - Universidade do Porto * * * * Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-2014 * * * *************************************************************************/ /** @file absf.yap @defgroup abs_file_name File Name Resolution Support for file name resolution through absolute_file_name/3 and friends. These utility built-ins describe a list of directories that are used by load_files/2 to search. They include pre-compiled paths plus user-defined directories, directories based on environment variables and registry information to search for files. @{ */ :- system_module( absolute_file_name, [absolute_file_name/2, absolute_file_name/3, add_to_path/1, add_to_path/2, path/1, remove_from_path/1], ['$full_filename'/3, '$system_library_directories'/2]). :- use_system_module( '$_boot', ['$system_catch'/4]). :- use_system_module( '$_errors', ['$do_error'/2]). :- use_system_module( '$_lists', [member/2]). /** absolute_file_name(+File:atom, +Options:list, +Path:atom) is nondet absolute_file_name(-File:atom, +Path:atom, +Options:list) is nondet _Options_ is a list of options to guide the conversion: - extensions(+ _ListOfExtensions_) List of file-extensions to try. Default is `''`. For each extension, absolute_file_name/3 will first add the extension and then verify the conditions imposed by the other options. If the condition fails, the next extension of the list is tried. Extensions may be specified both with dot, as `.ext`, or without, as plain `ext`. - relative_to(+ _FileOrDir_ ) Resolve the path relative to the given directory or directory the holding the given file. Without this option, paths are resolved relative to the working directory (see working_directory/2) or, if _Spec_ is atomic and absolute_file_name/3 is executed in a directive, it uses the current source-file as reference. - access(+ _Mode_ ) Imposes the condition access_file( _File_ , _Mode_ ). _Mode_ is one of `read`, `write`, `append`, `exist` or `none` (default). See also access_file/2. - file_type(+ _Type_ ) Defines suffixes matching one of several pre-specified type of files. Default mapping is as follows: 1. `txt` implies `[ '' ]`, 2. `prolog` implies `['.yap', '.pl', '.prolog', '']`, 3. `executable` implies `['.so', ',dylib', '.dll']` depending on the Operating system, 4. `qlf` implies `['.qlf', '']`, 5. `directory` implies `['']`, 6. The file-type `source` is an alias for `prolog` designed to support compatibility with SICStus Prolog. See also prolog_file_type/2. Notice that this predicate only returns non-directories, unless the option `file_type(directory)` is specified, or unless `access(none)`. - file_errors(`fail`/`error`) If `error` (default), throw and `existence_error` exception if the file cannot be found. If `fail`, stay silent. - solutions(`first`/`all`) If `first` (default), the search cannot backtrack. leaves no choice-point. Otherwise a choice-point will be left and backtracking may yield more solutions. - expand(`true`/`false`) If `true` (default is `false`) and _Spec_ is atomic, call expand_file_name/2 followed by member/2 on _Spec_ before proceeding. This is originally a SWI-Prolog extension. Compatibility considerations to common argument-order in ISO as well as SICStus absolute_file_name/3 forced us to be flexible here. If the last argument is a list and the second not, the arguments are swapped, making the call ~~~~~~~~~~~prolog absolute_file_name(+ _Spec_ , - _Path_ ,+ _Options_ ) ~~~~~~~~~~~ valid as well. */ absolute_file_name(File,TrueFileName,Opts) :- ( var(TrueFileName) -> true ; atom(TrueFileName), TrueFileName \= [] ), !, absolute_file_name(File,Opts,TrueFileName). absolute_file_name(File,Opts,TrueFileName) :- '$absolute_file_name'(File,Opts,TrueFileName,absolute_file_name(File,Opts,TrueFileName)). /** absolute_file_name(+Name:atom,+Path:atom) is nondet Converts the given file specification into an absolute path, using default options. See absolute_file_name/3 for details on the options. */ absolute_file_name(V,Out) :- var(V), !, % absolute_file_name needs commenting. '$do_error'(instantiation_error, absolute_file_name(V, Out)). absolute_file_name(user,user) :- !. absolute_file_name(File0,File) :- '$absolute_file_name'(File0,[access(none),file_type(txt),file_errors(fail),solutions(first)],File,absolute_file_name(File0,File)). '$full_filename'(F0,F,G) :- '$absolute_file_name'(F0,[access(read),file_type(source),file_errors(fail),solutions(first),expand(true)],F,G). '$absolute_file_name'(File, _Opts, _TrueFileName, G) :- var(File), !, '$do_error'(instantiation_error, G). '$absolute_file_name'(File,Opts,TrueFileName, G) :- '$process_fn_opts'(Opts,Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,G), /* our own local findall */ nb:nb_queue(Ref), ( '$find_in_path'(File,opts(Extensions,RelTo,Type,Access,FErrors,Expand,Debug),TrueFileName,G), nb:nb_queue_enqueue(Ref, TrueFileName), fail ; nb:nb_queue_close(Ref, FileNames, []) ), '$absolute_file_names'(Solutions, FileNames, FErrors, TrueFileName, File, G). '$absolute_file_names'(_Solutions, [], error, _, File, G) :- !, '$do_error'(existence_error(file,File),G). '$absolute_file_names'(Solutions, FileNames, _, TrueFileName, _, _) :- lists:member(TrueFileName, FileNames), (Solutions == first -> ! ; true). '$process_fn_opts'(V,_,_,_,_,_,_,_,_,G) :- var(V), !, '$do_error'(instantiation_error, G). '$process_fn_opts'([],[],_,txt,none,error,first,false,false,_) :- !. '$process_fn_opts'([Opt|Opts],Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,G) :- !, '$process_fn_opt'(Opt,Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions0,RelTo0,Type0,Access0,FErrors0,Solutions0,Expand0,Debug0,G), '$process_fn_opts'(Opts,Extensions0,RelTo0,Type0,Access0,FErrors0,Solutions0,Expand0,Debug0,G). '$process_fn_opts'(Opts,_Extensions,_RelTo,_Type,_Access,_FErrors,_Solutions,_Expand,_Debug,G) :- !, '$do_error'(type_error(list,Opts),G). '$process_fn_opt'(Opt,Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,G) :- var(Opt), !, '$do_error'(instantiation_error, G). '$process_fn_opt'(extensions(Extensions),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,_,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,G) :- !, '$check_fn_extensions'(Extensions,G). '$process_fn_opt'(relative_to(RelTo),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,_,Type,Access,FErrors,Solutions,Expand,Debug,G) :- !, '$check_atom'(RelTo,G). '$process_fn_opt'(access(Access),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,Type,_,FErrors,Solutions,Expand,Debug,G) :- !, '$check_atom'(Access,G). '$process_fn_opt'(file_type(Type),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,_,Access,FErrors,Solutions,Expand,Debug,G) :- !, '$check_fn_type'(Type,G). '$process_fn_opt'(file_errors(FErrors),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,Type,Access,_,Solutions,Expand,Debug,G) :- !, '$check_fn_errors'(FErrors,G). '$process_fn_opt'(solutions(Solutions),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,Type,Access,FErrors,_,Expand,Debug,G) :- !, '$check_fn_solutions'(Solutions,G). '$process_fn_opt'(expand(Expand),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,Type,Access,FErrors,Solutions,_,Debug,G) :- !, '$check_true_false'(Expand,G). '$process_fn_opt'(verbose_file_search(Debug),Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,_,G) :- !, '$check_true_false'(Debug,G). '$process_fn_opt'(Opt,Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,Extensions,RelTo,Type,Access,FErrors,Solutions,Expand,Debug,G) :- !, '$do_error'(domain_error(file_name_option,Opt),G). '$check_fn_extensions'(V,G) :- var(V), !, '$do_error'(instantiation_error, G). '$check_fn_extensions'([],_) :- !. '$check_fn_extensions'([A|L],G) :- !, '$check_atom'(A,G), '$check_fn_extensions'(L,G). '$check_fn_extensions'(T,G) :- !, '$do_error'(type_error(list,T),G). '$check_atom'(V,G) :- var(V), !, '$do_error'(instantiation_error, G). '$check_atom'(A,_G) :- atom(A), !. '$check_atom'(T,G) :- !, '$do_error'(type_error(atom,T),G). '$check_fn_type'(V,G) :- var(V), !, '$do_error'(instantiation_error, G). '$check_fn_type'(txt,_) :- !. '$check_fn_type'(prolog,_) :- !. '$check_fn_type'(source,_) :- !. '$check_fn_type'(executable,_) :- !. '$check_fn_type'(qlf,_) :- !. '$check_fn_type'(directory,_) :- !. '$check_fn_type'(T,G) :- atom(T), !, '$do_error'(domain_error(file_type,T),G). '$check_fn_type'(T,G) :- !, '$do_error'(type_error(atom,T),G). '$check_fn_errors'(V,G) :- var(V), !, '$do_error'(instantiation_error, G). '$check_fn_errors'(fail,_) :- !. '$check_fn_errors'(error,_) :- !. '$check_fn_errors'(T,G) :- atom(T), !, '$do_error'(domain_error(file_errors,T),G). '$check_fn_errors'(T,G) :- !, '$do_error'(type_error(atom,T),G). '$check_fn_solutions'(V,G) :- var(V), !, '$do_error'(instantiation_error, G). '$check_fn_solutions'(first,_) :- !. '$check_fn_solutions'(all,_) :- !. '$check_fn_solutions'(T,G) :- atom(T), !, '$do_error'(domain_error(solutions,T),G). '$check_fn_solutions'(T,G) :- !, '$do_error'(type_error(atom,T),G). '$check_true_false'(V,G) :- var(V), !, '$do_error'(instantiation_error, G). '$check_true_false'(true,_) :- !. '$check_true_false'(false,_) :- !. '$check_true_false'(T,G) :- atom(T), !, '$do_error'(domain_error(boolean,T),G). '$check_true_false'(T,G) :- !, '$do_error'(type_error(atom,T),G). % This sequence must be followed: % user and user_input are special; % library(F) must check library_directories % T(F) must check file_search_path % all must try search in path '$find_in_path'(user,_,user_input, _) :- !. '$find_in_path'(user_input,_,user_input, _) :- !. '$find_in_path'(S, Opts, NewFile, Call) :- S =.. [Name,File0], '$cat_file_name'(File0,File), !, '$dir_separator'(D), atom_codes(A,[D]), '$extend_path_directory'(Name, A, File, Opts, NewFile, Call). '$find_in_path'(File0,Opts,NewFile,_) :- '$cat_file_name'(File0,File), !, '$add_path'(File,PFile), '$get_abs_file'(PFile,Opts,AbsFile), '$search_in_path'(AbsFile,Opts,NewFile). '$find_in_path'(File,_,_,Call) :- '$do_error'(domain_error(source_sink,File),Call). % allow paths in File Name '$cat_file_name'(File0,File) :- atom(File0), !, File = File0. '$cat_file_name'(Atoms, File) :- '$to_list_of_atoms'(Atoms, List, []), atom_concat(List, File). '$to_list_of_atoms'(V, _, _) :- var(V), !, fail. '$to_list_of_atoms'(Atom, [Atom|L], L) :- atom(Atom), !. '$to_list_of_atoms'(Atoms, L1, LF) :- Atoms =.. [A,As,Bs], atom_codes(A,[D]), '$dir_separator'(D), '$to_list_of_atoms'(As, L1, [A|L2]), '$to_list_of_atoms'(Bs, L2, LF). '$get_abs_file'(File,opts(_,RelTo,_,_,_,Expand,_),AbsFile) :- '$swi_current_prolog_flag'(file_name_variables, OldF), '$swi_set_prolog_flag'(file_name_variables, Expand), ( '$absolute_file_name'(File,ExpFile) -> '$swi_set_prolog_flag'(file_name_variables, OldF) ; '$swi_set_prolog_flag'(file_name_variables, OldF), fail ), ( nonvar(RelTo) -> ( is_absolute_file_name(ExpFile) -> AbsFile = ExpFile ; '$dir_separator'(D), atom_codes(DA,[D]), atom_concat([RelTo, DA, ExpFile], AbsFile) ) ; AbsFile = ExpFile ). '$search_in_path'(File,opts(Extensions,_,Type,Access,_,_,_),F) :- '$add_extensions'(Extensions, File, F0), '$check_file'(F0, Type, Access, F). '$search_in_path'(File,opts(_,_,Type,Access,_,_,_),F) :- '$add_type_extensions'(Type, File, F0), '$check_file'(F0, Type, Access, F). '$check_file'(F, _Type, none, F) :- !. '$check_file'(F0, _Type, _Access, F0) :- % format('IN ~w~n', [F0]), yap_flag( c_cc, Flag), sub_atom( Flag, _, _, _, android), sub_atom( F0, 0, _, _, '/assets'), catch( open( F0, Access, S ), _, fail ), % format('~w~n', [F0]), !. '$check_file'(F0, Type, Access, F0) :- access_file(F0, Access), (Type == directory -> exists_directory(F0) ; \+ exists_directory(F0) % if it has a type cannot be a directory. ). '$add_extensions'([Ext|_],File,F) :- '$mk_sure_true_ext'(Ext,NExt), atom_concat([File,NExt],F). '$add_extensions'([_|Extensions],File,F) :- '$add_extensions'(Extensions,File,F). '$mk_sure_true_ext'(Ext,NExt) :- atom_codes(Ext,[C|L]), C \= 0'., !, atom_codes(NExt,[0'.,C|L]). '$mk_sure_true_ext'(Ext,Ext). '$add_type_extensions'(Type,File,F) :- ( Type == source -> NType = prolog ; NType = Type ), user:prolog_file_type(Ext, NType), atom_concat([File,'.',Ext],F). '$add_type_extensions'(_,File,File). '$add_path'(File,File) :- '$dir_separator'(D), atom_codes(DA,[D]), sub_atom(File, 0, 1, _, DA), !. '$add_path'(File,File). '$add_path'(File,PFile) :- recorded('$path',Path,_), atom_concat([Path,File],PFile). '$system_library_directories'(library, Dir) :- getenv('YAPSHAREDIR', Dirs), '$split_by_sep'(0, 0, Dirs, Dir). '$system_library_directories'(foreign, Dir) :- getenv('YAPLIBDIR', Dirs), '$split_by_sep'(0, 0, Dirs, Dir). '$system_library_directories'(commons, Dir) :- getenv('YAPCOMMONSDIR', Dirs), '$split_by_sep'(0, 0, Dirs, Dir). % windows has stuff installed in the registry '$system_library_directories'(Library, Dir) :- '$swi_current_prolog_flag'(windows, true), ( ( '$swi_current_prolog_flag'(address_bits, 64) -> ( HKEY='HKEY_LOCAL_MACHINE/Software/YAP/Prolog64'; HKEY='HKEY_CURRENT_USER/Software/YAP/Prolog64' ) ; ( HKEY='HKEY_LOCAL_MACHINE/Software/YAP/Prolog'; HKEY='HKEY_CURRENT_USER/Software/YAP/Prolog' ) ), % do not use once/1 % sanity check: are we running the binary mentioned in the registry? '$system_catch'(win_registry_get_value(HKEY,'bin', Bin), prolog,_,fail) ) -> true, '$swi_current_prolog_flag'(executable, Bin1), same_file(Bin, Bin1), '$system_catch'(win_registry_get_value(HKEY, Library, Dir), prolog,_,fail). % not installed on registry '$system_library_directories'(Library, Dir) :- '$yap_paths'(_DLLs, ODir1, OBinDir ), % '$absolute_file_name'( OBinDir, BinDir ), % '$swi_current_prolog_flag'(executable, Bin1), % prolog_to_os_filename( Bin2, Bin1 ), % file_directory_name( Bin2, BinDir1 ), % same_file( BinDir, BinDir1 ), ( Library == library -> atom_concat( ODir1, '/Yap' , ODir ) ; atom_concat( ODir1, '/PrologCommons' , ODir ) ), '$absolute_file_name'( ODir, Dir ), exists_directory( Dir ), !. % desperation: let's check the executable directory '$system_library_directories'(Library, Dir) :- '$swi_current_prolog_flag'(executable, Bin1), prolog_to_os_filename( Bin2, Bin1 ), file_directory_name( Bin2, Dir1 ), ( Library == library -> atom_concat( Dir1, '../share/Yap' , Dir ) ; atom_concat( Dir1, '../share/PrologCommons' , Dir ) ), exists_directory( Dir ), !. '$split_by_sep'(Start, Next, Dirs, Dir) :- '$swi_current_prolog_flag'(windows, true), '$split_by_sep'(Start, Next, Dirs, ';', Dir), !. '$split_by_sep'(Start, Next, Dirs, Dir) :- '$split_by_sep'(Start, Next, Dirs, ':', Dir). '$split_by_sep'(Start, Next, Dirs, Sep, Dir) :- sub_atom(Dirs, Next, 1, _, Let), !, '$continue_split_by_sep'(Let, Start, Next, Dirs, Sep, Dir). '$split_by_sep'(Start, Next, Dirs, _Sep, Dir) :- Next > Start, Len is Next-Start, sub_atom(Dirs, Start, Len, _, Dir). % closed a directory '$continue_split_by_sep'(Sep, Start, Next, Dirs, Sep, Dir) :- Sz is Next-Start, Sz > 0, sub_atom(Dirs, Start, Sz, _, Dir). % next dir '$continue_split_by_sep'(Sep , _Start, Next, Dirs, Sep, Dir) :- !, N1 is Next+1, '$split_by_sep'(N1, N1, Dirs, Dir). % same dir '$continue_split_by_sep'(_Let, Start, Next, Dirs, Sep, Dir) :- N1 is Next+1, '$split_by_sep'(Start, N1, Dirs, Sep, Dir). '$extend_path_directory'(_Name, D, File, _Opts, File, Call) :- is_absolute_file_name(File), !. '$extend_path_directory'(Name, D, File, Opts, NewFile, Call) :- user:file_search_path(Name, IDirs), ( atom(IDirs) -> '$split_by_sep'(0, 0, IDirs, Dir) ; Dir = IDirs ), '$extend_pathd'(Dir, D, File, Opts, NewFile, Call). '$extend_pathd'(Dir, A, File, Opts, NewFile, Goal) :- atom(Dir), !, '$add_file_to_dir'(Dir,A,File,NFile), '$find_in_path'(NFile, Opts, NewFile, Goal), !. '$extend_pathd'(Name, A, File, Opts, OFile, Goal) :- nonvar(Name), Name =.. [N,P0], '$add_file_to_dir'(P0,A,File,NFile), NewName =.. [N,NFile], '$find_in_path'(NewName, Opts, OFile, Goal). '$add_file_to_dir'(P0,A,Atoms,NFile) :- atom_concat([P0,A,Atoms],NFile). /** path(-Directories:list) is det,deprecated YAP specific procedure that returns a list of user-defined directories in the library search-path.We suggest using user:file_search_path/2 for compatibility with other Prologs. */ path(Path) :- findall(X,'$in_path'(X),Path). '$in_path'(X) :- recorded('$path',Path,_), atom_codes(Path,S), ( S = "" -> X = '.' ; atom_codes(X,S) ). /** add_to_path(+Directory:atom) is det,deprecated YAP-specific predicate to include directory in library search path. We suggest using user:file_search_path/2 for compatibility with other Prologs. */ add_to_path(New) :- add_to_path(New,last). /** add_to_path(+Directory:atom, +Position:atom) is det,deprecated YAP-specific predicate to include directory in front or back of library search path. We suggest using user:file_search_path/2 for compatibility with other Prologs and more extensive functionality. */ add_to_path(New,Pos) :- atom(New), !, '$check_path'(New,Str), atom_codes(Path,Str), '$add_to_path'(Path,Pos). '$add_to_path'(New,_) :- recorded('$path',New,R), erase(R), fail. '$add_to_path'(New,last) :- !, recordz('$path',New,_). '$add_to_path'(New,first) :- recorda('$path',New,_). /** remove_from_path(+Directory:atom) is det,deprecated */ remove_from_path(New) :- '$check_path'(New,Path), recorded('$path',Path,R), erase(R). '$check_path'(At,SAt) :- atom(At), !, atom_codes(At,S), '$check_path'(S,SAt). '$check_path'([],[]). '$check_path'([Ch],[Ch]) :- '$dir_separator'(Ch), !. '$check_path'([Ch],[Ch,A]) :- !, integer(Ch), '$dir_separator'(A). '$check_path'([N|S],[N|SN]) :- integer(N), '$check_path'(S,SN). /** user:library_directory(?Directory:atom) is nondet, dynamic Dynamic, multi-file predicate that succeeds when _Directory_ is a current library directory name. Asserted in the user module. Library directories are the places where files specified in the form `library( _File_ )` are searched by the predicates consult/1, reconsult/1, use_module/1, ensure_loaded/1, and load_files/2. */ :- multifile user:library_directory/1. :- dynamic user:library_directory/1. /** user:commons_directory(?Directory:atom) is nondet, dynamic */ :- multifile user:commons_directory/1. :- dynamic user:commons_directory/1. /** user:prolog_file_type(?Suffix:atom, ?Handler:atom) is nondet, dynamic This multifile/dynamic predicate relates a file extension _Suffix_ to a language or file type _Handler_. By default, it supports the extensions yap, pl, and prolog for prolog files and uses one of dll, so, or dylib for shared objects. Initial definition is: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~prolog prolog_file_type(yap, prolog). prolog_file_type(pl, prolog). prolog_file_type(prolog, prolog). prolog_file_type(A, prolog) :- current_prolog_flag(associate, A), A \== prolog, A \==pl, A \== yap. prolog_file_type(A, executable) :- current_prolog_flag(shared_object_extension, A). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ :- multifile user:prolog_file_type/2. :- dynamic user:prolog_file_type/2. user:prolog_file_type(yap, prolog). user:prolog_file_type(pl, prolog). user:prolog_file_type(prolog, prolog). user:prolog_file_type(A, prolog) :- current_prolog_flag(associate, A), A \== prolog, A \==pl, A \== yap. %user:prolog_file_type(qlf, prolog). %user:prolog_file_type(qlf, qlf). user:prolog_file_type(A, executable) :- current_prolog_flag(shared_object_extension, A). /** user:file_search_path(+Name:atom, -Directory:atom) is nondet Allows writing file names as compound terms. The _Name_ and _DIRECTORY_ must be atoms. The predicate may generate multiple solutions. The predicate is originally defined as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~prolog file_search_path(library, Dir) :- library_directory(Dir). file_search_path(commons, Dir) :- commons_directory(Dir). file_search_path(swi, Home) :- current_prolog_flag(home, Home). file_search_path(yap, Home) :- current_prolog_flag(home, Home). file_search_path(system, Dir) :- prolog_flag(host_type, Dir). file_search_path(foreign, yap('lib/Yap')). file_search_path(path, C) :- ( getenv('PATH', A), ( current_prolog_flag(windows, true) -> atomic_list_concat(B, ;, A) ; atomic_list_concat(B, :, A) ), lists:member(C, B) ). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Thus, `compile(library(A))` will search for a file using library_directory/1 to obtain the prefix, whereas 'compile(system(A))` would look at the `host_type` flag. @} */ :- multifile user:file_search_path/2. :- dynamic user:file_search_path/2. user:file_search_path(library, Dir) :- library_directory(Dir). user:file_search_path(commons, Dir) :- commons_directory(Dir). user:file_search_path(swi, Home) :- current_prolog_flag(home, Home). user:file_search_path(yap, Home) :- current_prolog_flag(home, Home). user:file_search_path(system, Dir) :- prolog_flag(host_type, Dir). user:file_search_path(foreign, yap('lib/Yap')). user:file_search_path(path, C) :- ( getenv('PATH', A), ( current_prolog_flag(windows, true) -> atomic_list_concat(B, ;, A) ; atomic_list_concat(B, :, A) ), lists:member(C, B) ).