From 712300027e2d87da1e9802c8c7bd4be151e4ecf2 Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Sat, 12 Feb 2011 00:26:28 +0000
Subject: [PATCH] include support for working_directory/2 as a system
 predicate.

---
 docs/yap.tex                | 14 +++++++-------
 library/system.yap          |  6 +-----
 packages/PLStream/pl-incl.h |  6 ++++++
 packages/PLStream/pl-yap.h  |  2 +-
 pl/utils.yap                |  3 +++
 5 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/docs/yap.tex b/docs/yap.tex
index a7dffd36e..fe8976f65 100644
--- a/docs/yap.tex
+++ b/docs/yap.tex
@@ -6895,6 +6895,13 @@ atoms.
 Execute a new shell.
 @end table
 
+@item working_directory(-@var{CurDir},?@var{NextDir})
+@findex  working_directory/2
+@syindex working_directory/2
+@cnindex working_directory/2    @c 
+Fetch the current directory at @var{CurDir}. If @var{NextDir} is bound
+to an atom, make its value the current working directory.
+
 @item alarm(+@var{Seconds},+@var{Callable},+@var{OldAlarm})
 @findex alarm/3
 @snindex alarm/3
@@ -11594,13 +11601,6 @@ The streams may be one of standard stream, @code{std}, null stream,
 @code{null}, or @code{pipe(S)}, where @var{S} is a pipe stream. Note
 that it is up to the user to close the pipe.
 
-@item working_directory(-@var{CurDir},?@var{NextDir})
-@findex  working_directory/2
-@syindex working_directory/2
-@cnindex working_directory/2    @c 
-Fetch the current directory at @var{CurDir}. If @var{NextDir} is bound
-to an atom, make its value the current working directory.
-
 @item popen(+@var{Command}, +@var{TYPE}, -@var{Stream})
 @findex  popen/3
 @syindex popen/3
diff --git a/library/system.yap b/library/system.yap
index 8270ab653..61e4461a0 100644
--- a/library/system.yap
+++ b/library/system.yap
@@ -43,7 +43,7 @@
 	mktime/2,
 	tmpnam/1,
 	tmp_file/2,
-  tmpdir/1,
+        tmpdir/1,
 	wait/2,
 	working_directory/2
           ]).
@@ -269,10 +269,6 @@ environ_split([61|SVal], [], SVal) :- !.
 environ_split([C|S],[C|SNa],SVal) :-
 	environ_split(S,SNa,SVal).
 
-working_directory(OLD, NEW) :-
-	getcwd(OLD),
-	cd(NEW).
-
 %
 % process execution
 %
diff --git a/packages/PLStream/pl-incl.h b/packages/PLStream/pl-incl.h
index edac799e1..57ef4d8d8 100755
--- a/packages/PLStream/pl-incl.h
+++ b/packages/PLStream/pl-incl.h
@@ -862,7 +862,13 @@ typedef double			real;
 #define false(s, a)		(!true((s), (a)))
 #define set(s, a)		((s)->flags |= (a))
 #define clear(s, a)		((s)->flags &= ~(a))
+#ifdef  DEBUG
+/* should have messages here */
+#undef DEBUG
 #define DEBUG(LEVEL, COMMAND)
+#else
+#define DEBUG(LEVEL, COMMAND)
+#endif
 
 #define forwards static		/* forwards function declarations */
 
diff --git a/packages/PLStream/pl-yap.h b/packages/PLStream/pl-yap.h
index 3e2892744..5d12751b8 100644
--- a/packages/PLStream/pl-yap.h
+++ b/packages/PLStream/pl-yap.h
@@ -27,7 +27,7 @@
 typedef YAP_Term	        Module;
 typedef YAP_Term	       *Word;		/* Anonymous 4 byte object */
 typedef YAP_Atom		Atom;
-typedef YAP_Term		(*Func)();	/* foreign functions */
+typedef YAP_Term		(*Func)(term_t);	/* foreign functions */
 
 const char *Yap_GetCurrentPredName(void);
 YAP_Int     Yap_GetCurrentPredArity(void);
diff --git a/pl/utils.yap b/pl/utils.yap
index 80829018f..59a777825 100644
--- a/pl/utils.yap
+++ b/pl/utils.yap
@@ -247,6 +247,9 @@ pwd :-
 	getcwd(X),
 	write(X), nl.
 
+working_directory(OLD, NEW) :-
+	swi_working_directory(OLD, NEW).
+
 unix(V) :- var(V), !,
 	'$do_error'(instantiation_error,unix(V)).
 unix(argv(L)) :- '$is_list_of_atoms'(L,L), !, '$argv'(L).