popen support
This commit is contained in:
Vitor Santos Costa
@@ -2,9 +2,9 @@
|
||||
* *
|
||||
* YAP Prolog *
|
||||
* *
|
||||
* Yap Prolog was developed at NCCUP - Universidade do Porto *
|
||||
* Yap Prolog was developed at NCCUP - Universidade do Porto *
|
||||
* *
|
||||
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
|
||||
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
|
||||
* *
|
||||
**************************************************************************
|
||||
* *
|
||||
@@ -74,44 +74,7 @@ are available through the `use_module(library(system))` command.
|
||||
|
||||
*/
|
||||
|
||||
/**
|
||||
|
||||
@pred datime(datime(- _Year_, - _Month_, - _DayOfTheMonth_, - _Hour_, - _Minute_, - _Second_)
|
||||
|
||||
The datime/1 procedure returns the current date and time, with
|
||||
information on _Year_, _Month_, _DayOfTheMonth_,
|
||||
_Hour_, _Minute_, and _Second_. The _Hour_ is returned
|
||||
on local time. This function uses the WIN32
|
||||
`GetLocalTime` function or the Unix `localtime` function.
|
||||
|
||||
~~~~~
|
||||
?- datime(X).
|
||||
|
||||
X = datime(2001,5,28,15,29,46) ?
|
||||
~~~~~
|
||||
|
||||
|
||||
*/
|
||||
|
||||
|
||||
/** @pred environ(+ _E_,- _S_)
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
Given an environment variable _E_ this predicate unifies the second argument _S_ with its value.
|
||||
|
||||
|
||||
*/
|
||||
/** @pred system(+ _S_)
|
||||
|
||||
|
||||
Passes command _S_ to the Bourne shell (on UNIX environments) or the
|
||||
current command interpreter in WIN32 environments.
|
||||
|
||||
|
||||
*/
|
||||
/** @pred working_directory(- _CurDir_,? _NextDir_)
|
||||
|
||||
|
||||
@@ -176,27 +139,6 @@ X = 'C:\\cygwin\\home\\administrator' ?
|
||||
~~~~~
|
||||
|
||||
|
||||
*/
|
||||
/** @pred exec(+ _Command_, _StandardStreams_,- _PID_)
|
||||
|
||||
|
||||
Execute command _Command_ with its standard streams connected to
|
||||
the list [_InputStream_, _OutputStream_, _ErrorStream_]. The
|
||||
process that executes the command is returned as _PID_. The
|
||||
command is executed by the default shell `bin/sh -c` in Unix.
|
||||
|
||||
The following example demonstrates the use of exec/3 to send a
|
||||
command and process its output:
|
||||
|
||||
~~~~~
|
||||
exec(ls,[std,pipe(S),null],P),repeat, get0(S,C), (C = -1, close(S) ! ; put(C)).
|
||||
~~~~~
|
||||
|
||||
The streams may be one of standard stream, `std`, null stream,
|
||||
`null`, or `pipe(S)`, where _S_ is a pipe stream. Note
|
||||
that it is up to the user to close the pipe.
|
||||
|
||||
|
||||
*/
|
||||
/** @pred file_exists(+ _File_)
|
||||
|
||||
@@ -289,37 +231,7 @@ process. An interface to the <tt>getpid</tt> function.
|
||||
|
||||
|
||||
*/
|
||||
/** @pred popen(+ _Command_, + _TYPE_, - _Stream_)
|
||||
|
||||
|
||||
Interface to the <tt>popen</tt> function. It opens a process by creating a
|
||||
pipe, forking and invoking _Command_ on the current shell. Since a
|
||||
pipe is by definition unidirectional the _Type_ argument may be
|
||||
`read` or `write`, not both. The stream should be closed
|
||||
using close/1, there is no need for a special `pclose`
|
||||
command.
|
||||
|
||||
The following example demonstrates the use of popen/3 to process
|
||||
the output of a command, as exec/3 would do:
|
||||
|
||||
~~~~~{.prolog}
|
||||
?- popen(ls,read,X),repeat, get0(X,C), (C = -1, ! ; put(C)).
|
||||
|
||||
X = 'C:\\cygwin\\home\\administrator' ?
|
||||
~~~~~
|
||||
|
||||
The WIN32 implementation of popen/3 relies on exec/3.
|
||||
|
||||
|
||||
*/
|
||||
/** @pred rename_file(+ _OldFile_,+ _NewFile_)
|
||||
|
||||
|
||||
Create file _OldFile_ to _NewFile_. This predicate uses the
|
||||
`C` built-in function `rename`.
|
||||
|
||||
|
||||
*/
|
||||
/** @pred read_link(+ SymbolicLink, -Link, -NewPath)
|
||||
|
||||
|
||||
@@ -423,6 +335,24 @@ also `absolute_file_name/2` and chdir/1.
|
||||
|
||||
% time builtins
|
||||
|
||||
/**
|
||||
|
||||
@pred datime(datime(- _Year_, - _Month_, - _DayOfTheMonth_, - _Hour_, - _Minute_, - _Second_)
|
||||
|
||||
The datime/1 procedure returns the current date and time, with
|
||||
information on _Year_, _Month_, _DayOfTheMonth_,
|
||||
_Hour_, _Minute_, and _Second_. The _Hour_ is returned
|
||||
on local time. This function uses the WIN32
|
||||
`GetLocalTime` function or the Unix `localtime` function.
|
||||
|
||||
~~~~~
|
||||
?- datime(X).
|
||||
|
||||
X = datime(2001,5,28,15,29,46) ?
|
||||
~~~~~
|
||||
|
||||
|
||||
*/
|
||||
datime(X) :-
|
||||
datime(X, Error),
|
||||
handle_system_internal(Error, off, datime(X)).
|
||||
@@ -567,10 +497,14 @@ file_property(File, Type, Size, Date, Permissions, LinkName) :-
|
||||
handle_system_internal(Error, off, file_property(File)).
|
||||
|
||||
|
||||
%
|
||||
% environment manipulation.
|
||||
%
|
||||
/** @pred environ(+E, -S)
|
||||
|
||||
Given an environment variable _E_ this predicate unifies the second
|
||||
argument _S_ with its value. _E_ may be bound to an atom, or just be
|
||||
unbound. In the latter case environ/2 will enumerate over all
|
||||
environment variables.
|
||||
|
||||
*/
|
||||
environ(Na,Val) :- var(Na), !,
|
||||
environ_enum(0,I),
|
||||
( p_environ(I,S) -> environ_split(S,SNa,SVal) ; !, fail ),
|
||||
@@ -597,9 +531,33 @@ environ_split([61|SVal], [], SVal) :- !.
|
||||
environ_split([C|S],[C|SNa],SVal) :-
|
||||
environ_split(S,SNa,SVal).
|
||||
|
||||
%
|
||||
% process execution
|
||||
%
|
||||
/** @pred exec(+ _Command_, _StandardStreams_,- _PID_)
|
||||
*
|
||||
*
|
||||
*
|
||||
* Execute command _Command_ with its standard streams connected to the
|
||||
* list [_InputStream_, _OutputStream_, _ErrorStream_]. A numeric
|
||||
* identifier to the process that executes the command is returned as
|
||||
* _PID_. The command is executed by the default shell `bin/sh -c` in
|
||||
* Unix.
|
||||
*
|
||||
* The following example demonstrates the use of exec/3 to send a
|
||||
* command and process its output:
|
||||
*
|
||||
* ~~~~~
|
||||
go :-
|
||||
exec(ls,[std,pipe(S),null],P),
|
||||
repeat,
|
||||
get0(S,C),
|
||||
(C = -1, close(S) ! ; put(C)).
|
||||
~~~~~
|
||||
*
|
||||
* The streams may be one of standard stream, `std`, null stream,
|
||||
* `null`, or `pipe(S)`, where _S_ is a pipe stream. Note
|
||||
* that it is up to the user to close the pipe.
|
||||
*
|
||||
*
|
||||
*/
|
||||
exec(Command, [StdIn, StdOut, StdErr], PID) :-
|
||||
G = exec(Command, [StdIn, StdOut, StdErr], PID),
|
||||
check_command_with_default_shell(Command, TrueCommand, G),
|
||||
@@ -652,8 +610,32 @@ close_temp_streams([S|Ss]) :-
|
||||
close(S),
|
||||
close_temp_streams(Ss).
|
||||
|
||||
popen(Command, Mode, Stream) :-
|
||||
open(pipe(Command), Mode, Stream).
|
||||
/** @pred popen(+ _Command_, + _TYPE_, - _Stream_)
|
||||
|
||||
* Provides the functionaluty of the Unix <tt>popen</tt> function. It
|
||||
* opens a process by creating a pipe, forking and invoking _Command_ on
|
||||
* the child process. Since a pipe is by definition unidirectional the
|
||||
* _Type_ argument may be `read` or `write`, not both. The stream should
|
||||
* be closed using close/1, there is no need for a special `pclose`
|
||||
* command.
|
||||
*
|
||||
* The following example demonstrates the use of popen/3 to process the
|
||||
* output of a command, note that popen/3 works as a simplified interface
|
||||
* to the exec/3 command:
|
||||
*
|
||||
~~~~~{.prolog}
|
||||
?- popen(ls,read,X),repeat, get0(X,C), (C = -1, ! ; put(C)).
|
||||
|
||||
X = 'C:\\cygwin\\home\\administrator' ?
|
||||
~~~~~
|
||||
*
|
||||
* The implementation of popen/3 relies on exec/3.
|
||||
*
|
||||
*/
|
||||
popen(Command, read, Stream) :-
|
||||
exec(Command, [std,pipe(Stream),std], Stream).
|
||||
popen(Command, write, Stream) :-
|
||||
exec(Command, [pipe(Stream),std,std], Stream).
|
||||
|
||||
check_command_with_default_shell(Com, ComF, G) :-
|
||||
check_command(Com, G),
|
||||
@@ -811,5 +793,23 @@ read_link(P,D,F) :-
|
||||
read_link(P, D),
|
||||
absolute_file_name(D, [], F).
|
||||
|
||||
/** @pred rename_file(+ _OldFile_,+ _NewFile_)
|
||||
|
||||
|
||||
Create file _OldFile_ to _NewFile_. This predicate uses the
|
||||
`C` built-in function `rename`.
|
||||
|
||||
|
||||
*/
|
||||
rename_file(F0, F) :-
|
||||
rename_file(F0, F, Error),
|
||||
handle_system_internal(Error, off, rename_file(F0, F))).
|
||||
|
||||
/** @pred system(+ _S_)
|
||||
|
||||
Passes command _S_ to the Bourne shell (on UNIX environments) or the
|
||||
current command interpreter in WIN32 environments.
|
||||
*/
|
||||
|
||||
/** @} */
|
||||
|
||||
|
||||
Reference in New Issue
Block a user