/* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@vu.nl
WWW: http://www.swi-prolog.org
Copyright (c) 1985-2018, University of Amsterdam
VU University Amsterdam
CWI, Amsterdam
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
:- module(shell,
[ shell/0,
ls/0,
ls/1, % +Pattern
cd/0,
cd/1, % +Dir
pushd/0,
pushd/1, % +Dir
dirs/0,
pwd/0,
popd/0,
mv/2, % +File1, +File2
rm/1 % +File1
]).
:- autoload(library(apply),[maplist/3,maplist/2]).
:- autoload(library(error),
[existence_error/2,instantiation_error/1,must_be/2]).
:- autoload(library(lists),[nth1/3]).
:- set_prolog_flag(generate_debug_info, false).
/** <module> Elementary shell commands
This library provides some basic (POSIX) shell commands defined in
Prolog, such as `pwd` and `ls` for situations where there is no shell
available or the shell output cannot be captured.
*/
%! shell
%
% Execute an interactive shell. The following options are tried to
% find a suitable shell command:
%
% 1. The Prolog flag `shell`
% 2. The environment variable ``$SHELL``
% 3. The Prolog flag `posix_shell`
% 4. The environment variable ``%comspec%`` (Windows only)
%
% @error existence_error(config, shell) if no suitable shell can be
% found.
shell :-
interective_shell(Shell),
access_file(Shell, execute),
!,
shell(Shell).
shell :-
existence_error(config, shell).
interective_shell(Shell) :-
current_prolog_flag(shell, Shell).
interective_shell(Shell) :-
getenv('SHELL', Shell).
interective_shell(Shell) :-
current_prolog_flag(posix_shell, Shell).
interective_shell(Shell) :-
current_prolog_flag(windows, true),
getenv(comspec, Shell). % Windows
%! cd.
%! cd(Dir).
%
% Change working directory
cd :-
cd(~).
cd(Dir) :-
name_to_file(Dir, Name),
working_directory(_, Name).
%! pushd.
%! pushd(+Dir).
%! popd.
%! dirs.
%
% Manage the _directory stack_:
%
% - pushd/1 is as cd/1, pushing th old directory on a stack
% - pushd/0 swaps the current directory with the top of the
% stack
% - popd/0 pops to the top of the stack
% - dirs/0 lists the current directory and the stack.
:- dynamic
stack/1.
pushd :-
pushd(+1).
pushd(N) :-
integer(N),
!,
findall(D, stack(D), Ds),
( nth1(N, Ds, Go),
retract(stack(Go))
-> pushd(Go),
print_message(information, shell(directory(Go)))
; warning('Directory stack not that deep', []),
fail
).
pushd(Dir) :-
name_to_file(Dir, Name),
working_directory(Old, Name),
asserta(stack(Old)).
popd :-
retract(stack(Dir)),
!,
working_directory(_, Dir),
print_message(information, shell(directory(Dir))).
popd :-
warning('Directory stack empty', []),
fail.
dirs :-
working_directory(WD, WD),
findall(D, stack(D), Dirs),
maplist(dir_name, [WD|Dirs], Results),
print_message(information, shell(file_set(Results))).
%! pwd
%
% Print current working directory
pwd :-
working_directory(WD, WD),
print_message(information, format('~w', [WD])).
dir_name('/', '/') :- !.
dir_name(Path, Name) :-
atom_concat(P, /, Path),
!,
dir_name(P, Name).
dir_name(Path, Name) :-
current_prolog_flag(unix, true),
expand_file_name('~', [Home0]),
( atom_concat(Home, /, Home0)
-> true
; Home = Home0
),
atom_concat(Home, FromHome, Path),
!,
atom_concat('~', FromHome, Name).
dir_name(Path, Path).
%! ls.
%! ls(+Pattern).
%
% Listing similar to Unix =ls -F=, flagging directories with =/=.
ls :-
ls('.').
ls(Spec) :-
name_to_files(Spec, Matches),
ls_(Matches).
ls_([]) :-
!,
warning('No Match', []).
ls_([Dir]) :-
exists_directory(Dir),
!,
atom_concat(Dir, '/*', Pattern),
expand_file_name(Pattern, Files),
maplist(tagged_file_in_dir, Files, Results),
print_message(information, shell(file_set(Results))).
ls_(Files) :-
maplist(tag_file, Files, Results),
print_message(information, shell(file_set(Results))).
tagged_file_in_dir(File, Result) :-
file_base_name(File, Base),
( exists_directory(File)
-> atom_concat(Base, /, Result)
; Result = Base
).
tag_file(File, Dir) :-
exists_directory(File),
!,
atom_concat(File, /, Dir).
tag_file(File, File).
%! mv(+From, +To) is det.
%
% Move (Rename) a file. If To is a directory, From is moved into
% the directory. Uses expand_file_name/2 on the From argument.
mv(From, To) :-
name_to_files(From, Src),
name_to_new_file(To, Dest),
mv_(Src, Dest).
mv_([One], Dest) :-
\+ exists_directory(Dest),
!,
rename_file(One, Dest).
mv_(Multi, Dest) :-
( exists_directory(Dest)
-> maplist(mv_to_dir(Dest), Multi)
; print_message(warning, format('Not a directory: ~w', [Dest])),
fail
).
mv_to_dir(Dest, Src) :-
file_base_name(Src, Name),
atomic_list_concat([Dest, Name], /, Target),
rename_file(Src, Target).
%! rm(+File) is det.
%
% Remove (unlink) a file
rm(File) :-
name_to_file(File, A),
delete_file(A).
%! name_to_file(+Name, -File)
%
% Convert Name into a single file.
name_to_file(Spec, File) :-
name_to_files(Spec, Files),
( Files = [File]
-> true
; print_message(warning, format('Ambiguous: ~w', [Spec])),
fail
).
name_to_new_file(Spec, File) :-
name_to_files(Spec, Files, false),
( Files = [File]
-> true
; print_message(warning, format('Ambiguous: ~w', [Spec])),
fail
).
name_to_files(Spec, Files) :-
name_to_files(Spec, Files, true).
name_to_files(Spec, Files, Exists) :-
name_to_files_(Spec, Files, Exists),
( Files == []
-> print_message(warning, format('No match: ~w', [Spec])),
fail
; true
).
name_to_files_(Spec, Files, _) :-
compound(Spec),
compound_name_arity(Spec, _Alias, 1),
!,
findall(File,
( absolute_file_name(Spec, File,
[ access(exist),
file_type(directory),
file_errors(fail),
solutions(all)
])
; absolute_file_name(Spec, File,
[ access(exist),
file_errors(fail),
solutions(all)
])
),
Files).
name_to_files_(Spec, Files, Exists) :-
file_name_to_atom(Spec, S1),
expand_file_name(S1, Files0),
( Exists == true,
Files0 == [S1],
\+ access_file(S1, exist)
-> warning('"~w" does not exist', [S1]),
fail
; Files = Files0
).
file_name_to_atom(Spec, File) :-
atomic(Spec),
!,
atom_string(File, Spec).
file_name_to_atom(Spec, File) :-
phrase(segments(Spec), L),
atomic_list_concat(L, /, File).
segments(Var) -->
{ var(Var),
!,
instantiation_error(Var)
}.
segments(A/B) -->
!,
segments(A),
segments(B).
segments(A) -->
{ must_be(atomic, A) },
[ A ].
%! warning(+Fmt, +Args:list) is det.
warning(Fmt, Args) :-
print_message(warning, format(Fmt, Args)).
:- multifile prolog:message//1.
prolog:message(shell(file_set(Files))) -->
{ catch(tty_size(_, Width), _, Width = 80)
},
table(Files, Width).
prolog:message(shell(directory(Path))) -->
{ dir_name(Path, Name) },
[ '~w'-[Name] ].
%! table(+List, +Width)//
%
% Produce a tabular layout to list all elements of List on lines
% with a maximum width of Width. Elements are placed as =ls= does:
%
% ==
% 1 4 7
% 2 5 8
% 3 6
% ==
table(List, Width) -->
{ table_layout(List, Width, Layout),
compound_name_arguments(Array, a, List)
},
table(0, Array, Layout).
table(I, Array, Layout) -->
{ Cols = Layout.cols,
Index is I // Cols + (I mod Cols) * Layout.rows + 1,
( (I+1) mod Cols =:= 0
-> NL = true
; NL = false
)
},
( { arg(Index, Array, Atom) }
-> ( { NL == false }
-> [ '~|~w~t~*+'-[Atom, Layout.col_width] ]
; [ '~w'-[Atom] ]
)
; []
),
( { I2 is I+1,
I2 < Cols*Layout.rows
}
-> ( { NL == true }
-> [ nl ]
; []
),
table(I2, Array, Layout)
; []
).
table_layout(Atoms, Width, _{cols:Cols, rows:Rows, col_width:ColWidth}) :-
length(Atoms, L),
longest(Atoms, Longest),
Cols is max(1, Width // (Longest + 3)),
Rows is integer(L / Cols + 0.49999), % should be ceil/1
ColWidth is Width // Cols.
longest(List, Longest) :-
longest(List, 0, Longest).
longest([], M, M) :- !.
longest([H|T], Sofar, M) :-
atom_length(H, L),
L >= Sofar,
!,
longest(T, L, M).
longest([_|T], S, M) :-
longest(T, S, M).