--- loncom/lonnet/perl/lonnet.pm	2006/02/10 10:01:32	1.709
+++ loncom/lonnet/perl/lonnet.pm	2006/02/23 18:15:16	1.713
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.709 2006/02/10 10:01:32 albertel Exp $
+# $Id: lonnet.pm,v 1.713 2006/02/23 18:15:16 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1145,7 +1145,9 @@ sub ssi {
     my $ua=new LWP::UserAgent;
     
     my $request;
-    
+
+    $form{'no_update_last_known'}=1;
+
     if (%form) {
       $request=new HTTP::Request('POST',"http://".$ENV{'HTTP_HOST'}.$fn);
       $request->content(join('&',map { &escape($_).'='.&escape($form{$_}) } keys %form));
@@ -3450,16 +3452,17 @@ sub allowed {
    return 'F';
 }
 
+sub split_uri_for_cond {
+    my $uri=&deversion(&declutter(shift));
+    my @uriparts=split(/\//,$uri);
+    my $filename=pop(@uriparts);
+    my $pathname=join('/',@uriparts);
+    return ($pathname,$filename);
+}
 # --------------------------------------------------- Is a resource on the map?
 
 sub is_on_map {
-    my $uri=&deversion(&declutter(shift));
-    my @uriparts=split(/\//,$uri);
-    my $filename=$uriparts[$#uriparts];
-    my $pathname=$uri;
-    $pathname=~s|/\Q$filename\E$||;
-    $pathname=~s/^adm\/wrapper\///;
-    $pathname=~s/^adm\/coursedocs\/showdoc\///;
+    my ($pathname,$filename) = &split_uri_for_cond(shift);
     #Trying to find the conditional for the file
     my $match=($env{'acc.res.'.$env{'request.course.id'}.'.'.$pathname}=~
 	       /\&\Q$filename\E\:([\d\|]+)\&/);
@@ -4664,13 +4667,62 @@ sub GetFileTimestamp {
     }
 }
 
+sub stat_file {
+    my ($uri) = @_;
+    $uri = &clutter($uri);
+    my ($udom,$uname,$file,$dir);
+    if ($uri =~ m-^/(uploaded|editupload)/-) {
+	($udom,$uname,$file) =
+	    ($uri =~ m-/(?:uploaded|editupload)/?([^/]*)/?([^/]*)/?(.*)-);
+	$file = 'userfiles/'.$file;
+	$dir = &Apache::loncommon::propath($udom,$uname);
+    }
+    if ($uri =~ m-^/res/-) {
+	($udom,$uname) = 
+	    ($uri =~ m-/(?:res)/?([^/]*)/?([^/]*)/-);
+	$file = $uri;
+    }
+
+    if (!$udom || !$uname || !$file) {
+	# unable to handle the uri
+	return ();
+    }
+
+    my ($result) = &dirlist($file,$udom,$uname,$dir);
+    my @stats = split('&', $result);
+    if($stats[0] ne 'empty' && $stats[0] ne 'no_such_dir') {
+	shift(@stats); #filename is first
+	return @stats;
+    }
+    return ();
+}
+
 # -------------------------------------------------------- Value of a Condition
 
+# gets the value of a specific preevaluated condition
+#    stored in the string  $env{user.state.<cid>}
+# or looks up a condition reference in the bighash and if if hasn't
+# already been evaluated recurses into docondval to get the value of
+# the condition, then memoizing it to 
+#   $env{user.state.<cid>.<condition>}
 sub directcondval {
     my $number=shift;
     if (!defined($env{'user.state.'.$env{'request.course.id'}})) {
 	&Apache::lonuserstate::evalstate();
     }
+    if (exists($env{'user.state.'.$env{'request.course.id'}.".$number"})) {
+	return $env{'user.state.'.$env{'request.course.id'}.".$number"};
+    } elsif ($number =~ /^_/) {
+	my $sub_condition;
+	if (tie(my %bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
+		&GDBM_READER(),0640)) {
+	    $sub_condition=$bighash{'conditions'.$number};
+	    untie(%bighash);
+	}
+	my $value = &docondval($sub_condition);
+	&appenv('user.state.'.$env{'request.course.id'}.".$number" => $value);
+	return $value;
+    }
     if ($env{'user.state.'.$env{'request.course.id'}}) {
        return substr($env{'user.state.'.$env{'request.course.id'}},$number,1);
     } else {
@@ -4678,43 +4730,49 @@ sub directcondval {
     }
 }
 
+# get the collection of conditions for this resource
 sub condval {
     my $condidx=shift;
-    my $result=0;
     my $allpathcond='';
-    foreach (split(/\|/,$condidx)) {
-       if (defined($env{'acc.cond.'.$env{'request.course.id'}.'.'.$_})) {
-	   $allpathcond.=
-               '('.$env{'acc.cond.'.$env{'request.course.id'}.'.'.$_}.')|';
-       }
+    foreach my $cond (split(/\|/,$condidx)) {
+	if (defined($env{'acc.cond.'.$env{'request.course.id'}.'.'.$cond})) {
+	    $allpathcond.=
+		'('.$env{'acc.cond.'.$env{'request.course.id'}.'.'.$cond}.')|';
+	}
     }
     $allpathcond=~s/\|$//;
-    if ($env{'request.course.id'}) {
-       if ($allpathcond) {
-          my $operand='|';
-	  my @stack;
-           foreach ($allpathcond=~/(\d+|\(|\)|\&|\|)/g) {
-              if ($_ eq '(') {
-                 push @stack,($operand,$result)
-              } elsif ($_ eq ')') {
-                  my $before=pop @stack;
-		  if (pop @stack eq '&') {
-		      $result=$result>$before?$before:$result;
-                  } else {
-                      $result=$result>$before?$result:$before;
-                  }
-              } elsif (($_ eq '&') || ($_ eq '|')) {
-                  $operand=$_;
-              } else {
-                  my $new=directcondval($_);
-                  if ($operand eq '&') {
-                     $result=$result>$new?$new:$result;
-                  } else {
-                     $result=$result>$new?$result:$new;
-                  }
-              }
-          }
-       }
+    return &docondval($allpathcond);
+}
+
+#evaluates an expression of conditions
+sub docondval {
+    my ($allpathcond) = @_;
+    my $result=0;
+    if ($env{'request.course.id'}
+	&& defined($allpathcond)) {
+	my $operand='|';
+	my @stack;
+	foreach my $chunk ($allpathcond=~/(\d+|_\d+\.\d+|\(|\)|\&|\|)/g) {
+	    if ($chunk eq '(') {
+		push @stack,($operand,$result);
+	    } elsif ($chunk eq ')') {
+		my $before=pop @stack;
+		if (pop @stack eq '&') {
+		    $result=$result>$before?$before:$result;
+		} else {
+		    $result=$result>$before?$result:$before;
+		}
+	    } elsif (($chunk eq '&') || ($chunk eq '|')) {
+		$operand=$chunk;
+	    } else {
+		my $new=directcondval($chunk);
+		if ($operand eq '&') {
+		    $result=$result>$new?$new:$result;
+		} else {
+		    $result=$result>$new?$result:$new;
+		}
+	    }
+	}
     }
     return $result;
 }
@@ -5470,9 +5528,12 @@ sub symblist {
     if (($env{'request.course.fn'}) && (%newhash)) {
         if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
                       &GDBM_WRCREAT(),0640)) {
-	    foreach (keys %newhash) {
-                $hash{declutter($_)}=&encode_symb($mapname,$newhash{$_}->[1],
-						  $newhash{$_}->[0]);
+	    foreach my $url (keys %newhash) {
+		next if ($url eq 'last_known'
+			 && $env{'form.no_update_last_known'});
+		$hash{declutter($url)}=&encode_symb($mapname,
+						    $newhash{$url}->[1],
+						    $newhash{$url}->[0]);
             }
             if (untie(%hash)) {
 		return 'ok';
@@ -7333,6 +7394,16 @@ getfile($file,$caller) : two cases - req
    - returns the entire contents of a file or -1; 
    it properly subscribes to and replicates the file if neccessary.
 
+
+=item *
+
+stat_file($url) : $url is expected to be a /res/ or /uploaded/ style file
+                  reference
+
+returns either a stat() list of data about the file or an empty list
+if the file doesn't exist or couldn't find out about it (connection
+problems or user unknown)
+
 =item *
 
 filelocation($dir,$file) : returns file system location of a file