223 lines
4.8 KiB
Prolog
223 lines
4.8 KiB
Prolog
/*************************************************************************
|
|
* *
|
|
* YAP Prolog *
|
|
* *
|
|
* Yap Prolog was developed at NCCUP - Universidade do Porto *
|
|
* *
|
|
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
|
|
* *
|
|
*************************************************************************/
|
|
|
|
|
|
:- system_module( '$os', [
|
|
cd/0,
|
|
cd/1,
|
|
getcwd/1,
|
|
ls/0,
|
|
pwd/0,
|
|
unix/1,
|
|
putenv/2,
|
|
getenv/2,
|
|
setenv/2
|
|
], [] ).
|
|
:- use_system_module( '$_errors', ['$do_error'/2]).
|
|
|
|
/**
|
|
@defgroup YAPOS Access to Operating System Functionality
|
|
@ingroup builtins
|
|
|
|
The following built-in predicates allow access to underlying
|
|
Operating System functionality.
|
|
|
|
%% @{
|
|
|
|
*/
|
|
|
|
/** @pred cd
|
|
|
|
Changes the current directory (on UNIX environments) to the user's home directory.
|
|
|
|
|
|
*/
|
|
cd :-
|
|
cd('~').
|
|
|
|
/** @pred cd(+ _D_)
|
|
|
|
|
|
Changes the current directory (on UNIX environments).
|
|
|
|
|
|
*/
|
|
cd(F) :-
|
|
absolute_file_name(F, Dir, [file_type(directory),file_errors(fail),access(execute),expand(true)]),
|
|
working_directory(_, Dir).
|
|
|
|
/** @pred getcwd(- _D_)
|
|
|
|
|
|
Unify the current directory, represented as an atom, with the argument
|
|
_D_.
|
|
|
|
|
|
*/
|
|
getcwd(Dir) :- working_directory(Dir, Dir).
|
|
|
|
/** @pred ls
|
|
|
|
|
|
Prints a list of all files in the current directory.
|
|
|
|
|
|
*/
|
|
ls :-
|
|
getcwd(X),
|
|
'$load_system_ls'(X,L),
|
|
'$do_print_files'(L).
|
|
|
|
'$load_system_ls'(X,L) :-
|
|
'$undefined'(directory_files(X, L), system),
|
|
load_files(library(system),[silent(true)]),
|
|
fail.
|
|
'$load_system_ls'(X,L) :-
|
|
system:directory_files(X, L).
|
|
|
|
|
|
'$do_print_files'([]) :-
|
|
nl.
|
|
'$do_print_files'([F| Fs]) :-
|
|
'$do_print_file'(F),
|
|
'$do_print_files'(Fs).
|
|
|
|
'$do_print_file'('.') :- !.
|
|
'$do_print_file'('..') :- !.
|
|
'$do_print_file'(F) :- atom_concat('.', _, F), !.
|
|
'$do_print_file'(F) :-
|
|
write(F), write(' ').
|
|
|
|
/** @pred pwd
|
|
|
|
|
|
Prints the current directory.
|
|
|
|
|
|
*/
|
|
pwd :-
|
|
getcwd(X),
|
|
write(X), nl.
|
|
|
|
/** @pred unix(+ _S_)
|
|
|
|
|
|
Access to Unix-like functionality:
|
|
|
|
+ argv/1
|
|
Return a list of arguments to the program. These are the arguments that
|
|
follow a `--`, as in the usual Unix convention.
|
|
+ cd/0
|
|
Change to home directory.
|
|
+ cd/1
|
|
Change to given directory. Acceptable directory names are strings or
|
|
atoms.
|
|
+ environ/2
|
|
If the first argument is an atom, unify the second argument with the
|
|
value of the corresponding environment variable.
|
|
+ getcwd/1
|
|
Unify the first argument with an atom representing the current directory.
|
|
+ putenv/2
|
|
Set environment variable _E_ to the value _S_. If the
|
|
environment variable _E_ does not exist, create a new one. Both the
|
|
environment variable and the value must be atoms.
|
|
+ shell/1
|
|
Execute command under current shell. Acceptable commands are strings or
|
|
atoms.
|
|
+ system/1
|
|
Execute command with `/bin/sh`. Acceptable commands are strings or
|
|
atoms.
|
|
+ shell/0
|
|
Execute a new shell.
|
|
|
|
|
|
|
|
*/
|
|
unix(V) :- var(V), !,
|
|
'$do_error'(instantiation_error,unix(V)).
|
|
unix(argv(L)) :-
|
|
current_prolog_flag(argv, L).
|
|
unix(cd) :- cd('~').
|
|
unix(cd(A)) :- cd(A).
|
|
unix(environ(X,Y)) :- '$do_environ'(X,Y).
|
|
unix(getcwd(X)) :- getcwd(X).
|
|
unix(shell(V)) :- var(V), !,
|
|
'$do_error'(instantiation_error,unix(shell(V))).
|
|
unix(shell(A)) :- atom(A), !, '$shell'(A).
|
|
unix(shell(A)) :- string(A), !, '$shell'(A).
|
|
unix(shell(V)) :-
|
|
'$do_error'(type_error(atomic,V),unix(shell(V))).
|
|
unix(system(V)) :- var(V), !,
|
|
'$do_error'(instantiation_error,unix(system(V))).
|
|
unix(system(A)) :- atom(A), !, system(A).
|
|
unix(system(A)) :- string(A), !, system(A).
|
|
unix(system(V)) :-
|
|
'$do_error'(type_error(atom,V),unix(system(V))).
|
|
unix(shell) :- sh.
|
|
unix(putenv(X,Y)) :- '$putenv'(X,Y).
|
|
|
|
|
|
'$is_list_of_atoms'(V,_) :- var(V),!.
|
|
'$is_list_of_atoms'([],_) :- !.
|
|
'$is_list_of_atoms'([H|L],L0) :- !,
|
|
'$check_if_head_may_be_atom'(H,L0),
|
|
'$is_list_of_atoms'(L,L0).
|
|
'$is_list_of_atoms'(H,L0) :-
|
|
'$do_error'(type_error(list,H),unix(argv(L0))).
|
|
|
|
'$check_if_head_may_be_atom'(H,_) :-
|
|
var(H), !.
|
|
'$check_if_head_may_be_atom'(H,_) :-
|
|
atom(H), !.
|
|
'$check_if_head_may_be_atom'(H,L0) :-
|
|
'$do_error'(type_error(atom,H),unix(argv(L0))).
|
|
|
|
|
|
'$do_environ'(X, Y) :-
|
|
var(X), !,
|
|
'$do_error'(instantiation_error,unix(environ(X,Y))).
|
|
'$do_environ'(X, Y) :- atom(X), !,
|
|
'$getenv'(X,Y).
|
|
'$do_environ'(X, Y) :-
|
|
'$do_error'(type_error(atom,X),unix(environ(X,Y))).
|
|
|
|
|
|
/** @pred putenv(+ _E_,+ _S_)
|
|
|
|
|
|
Set environment variable _E_ to the value _S_. If the
|
|
environment variable _E_ does not exist, create a new one. Both the
|
|
environment variable and the value must be atoms.
|
|
|
|
|
|
*/
|
|
putenv(Na,Val) :-
|
|
'$putenv'(Na,Val).
|
|
|
|
getenv(Na,Val) :-
|
|
'$getenv'(Na,Val).
|
|
|
|
/** @pred setenv(+ _Name_,+ _Value_)
|
|
|
|
|
|
Set environment variable. _Name_ and _Value_ should be
|
|
instantiated to atoms or integers. The environment variable will be
|
|
passed to `shell/[0-2]` and can be requested using `getenv/2`.
|
|
They also influence expand_file_name/2.
|
|
|
|
|
|
*/
|
|
setenv(Na,Val) :-
|
|
'$putenv'(Na,Val).
|
|
|
|
/**
|
|
@}
|
|
*/
|