--- loncom/lonnet/perl/lonnet.pm	2017/08/27 13:48:52	1.1353
+++ loncom/lonnet/perl/lonnet.pm	2017/12/18 23:14:03	1.1362
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1353 2017/08/27 13:48:52 raeburn Exp $
+# $Id: lonnet.pm,v 1.1362 2017/12/18 23:14:03 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -146,7 +146,7 @@ our @EXPORT = qw(%env);
 sub logtouch {
     my $execdir=$perlvar{'lonDaemons'};
     unless (-e "$execdir/logs/lonnet.log") {	
-	open(my $fh,">>$execdir/logs/lonnet.log");
+	open(my $fh,">>","$execdir/logs/lonnet.log");
 	close $fh;
     }
     my ($wwwuid,$wwwgid)=(getpwnam('www'))[2,3];
@@ -158,7 +158,7 @@ sub logthis {
     my $execdir=$perlvar{'lonDaemons'};
     my $now=time;
     my $local=localtime($now);
-    if (open(my $fh,">>$execdir/logs/lonnet.log")) {
+    if (open(my $fh,">>","$execdir/logs/lonnet.log")) {
 	my $logstring = $local. " ($$): ".$message."\n"; # Keep any \'s in string.
 	print $fh $logstring;
 	close($fh);
@@ -171,7 +171,7 @@ sub logperm {
     my $execdir=$perlvar{'lonDaemons'};
     my $now=time;
     my $local=localtime($now);
-    if (open(my $fh,">>$execdir/logs/lonnet.perm.log")) {
+    if (open(my $fh,">>","$execdir/logs/lonnet.perm.log")) {
 	print $fh "$now:$message:$local\n";
 	close($fh);
     }
@@ -485,7 +485,7 @@ sub reconlonc {
 
     &logthis("Trying to reconnect lonc");
     my $loncfile="$perlvar{'lonDaemons'}/logs/lonc.pid";
-    if (open(my $fh,"<$loncfile")) {
+    if (open(my $fh,"<",$loncfile)) {
 	my $loncpid=<$fh>;
         chomp($loncpid);
         if (kill 0 => $loncpid) {
@@ -525,7 +525,7 @@ sub critical {
             $dumpcount++;
             {
 		my $dfh;
-		if (open($dfh,">$dfilename")) {
+		if (open($dfh,">",$dfilename)) {
 		    print $dfh "$cmd\n"; 
 		    close($dfh);
 		}
@@ -534,7 +534,7 @@ sub critical {
             my $wcmd='';
             {
 		my $dfh;
-		if (open($dfh,"<$dfilename")) {
+		if (open($dfh,"<",$dfilename)) {
 		    $wcmd=<$dfh>; 
 		    close($dfh);
 		}
@@ -650,7 +650,7 @@ sub transfer_profile_to_env {
 
 # ---------------------------------------------------- Check for valid session 
 sub check_for_valid_session {
-    my ($r,$name,$userhashref) = @_;
+    my ($r,$name,$userhashref,$domref) = @_;
     my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
     my ($linkname,$pubname);
     if ($name eq '') {
@@ -678,7 +678,16 @@ sub check_for_valid_session {
     } else {
         $lonidsdir=$r->dir_config('lonIDsDir');
     }
-    return undef if (!-e "$lonidsdir/$handle.id");
+    if (!-e "$lonidsdir/$handle.id") {
+        if ((ref($domref)) && ($name eq 'lonID') && 
+            ($handle =~ /^($match_username)\_\d+\_($match_domain)\_(.+)$/)) {
+            my ($possuname,$possudom,$possuhome) = ($1,$2,$3);
+            if ((&domain($possudom) ne '') && (&homeserver($possuname,$possudom) eq $possuhome)) {
+                $$domref = $possudom;
+            }
+        }
+        return undef;
+    }
 
     my $opened = open(my $idf,'+<',"$lonidsdir/$handle.id");
     return undef if (!$opened);
@@ -698,6 +707,7 @@ sub check_for_valid_session {
     if (ref($userhashref) eq 'HASH') {
         $userhashref->{'name'} = $disk_env{'user.name'};
         $userhashref->{'domain'} = $disk_env{'user.domain'};
+        $userhashref->{'lti'} = $disk_env{'request.lti.login'};
     }
 
     return $handle;
@@ -2085,6 +2095,16 @@ sub inst_directory_query {
     my $homeserver = &domain($udom,'primary');
     my $outcome;
     if ($homeserver ne '') {
+        unless ($homeserver eq $perlvar{'lonHostID'}) {
+            if ($srch->{'srchby'} eq 'email') {
+                my $lcrev = &get_server_loncaparev(undef,$homeserver);
+                my ($major,$minor) = ($lcrev =~ /^\'?(\d+)\.(\d+)\.[\w.\-]+\'?$/);
+                if (($major eq '' && $minor eq '') || ($major < 2) ||
+                    (($major == 2) && ($minor < 12))) {
+                    return;
+                }
+            }
+        }
 	my $queryid=&reply("querysend:instdirsearch:".
 			   &escape($srch->{'srchby'}).':'.
 			   &escape($srch->{'srchterm'}).':'.
@@ -2126,6 +2146,14 @@ sub usersearch {
     my $query = 'usersearch';
     foreach my $tryserver (keys(%libserv)) {
         if (&host_domain($tryserver) eq $dom) {
+            unless ($tryserver eq $perlvar{'lonHostID'}) {
+                if ($srch->{'srchby'} eq 'email') {
+                    my $lcrev = &get_server_loncaparev(undef,$tryserver);
+                    my ($major,$minor) = ($lcrev =~ /^\'?(\d+)\.(\d+)\.[\w.\-]+\'?$/);
+                    next if (($major eq '' && $minor eq '') || ($major < 2) ||
+                             (($major == 2) && ($minor < 12)));
+                }
+            }
             my $host=&hostname($tryserver);
             my $queryid=
                 &reply("querysend:".&escape($query).':'.
@@ -2444,6 +2472,9 @@ sub get_domain_defaults {
         } elsif ($domconfig{'coursedefaults'}{'canclone'}) {
             $domdefaults{'canclone'}=$domconfig{'coursedefaults'}{'canclone'};
         }
+        if ($domconfig{'coursedefaults'}{'texengine'}) {
+            $domdefaults{'texengine'} = $domconfig{'coursedefaults'}{'texengine'};
+        } 
     }
     if (ref($domconfig{'usersessions'}) eq 'HASH') {
         if (ref($domconfig{'usersessions'}{'remote'}) eq 'HASH') {
@@ -3171,9 +3202,15 @@ sub externalssi {
     }
 }
 
+
+# If the local copy of a replicated resource is outdated, trigger a  
+# connection from the homeserver to flush the delayed queue. If no update 
+# happens, remove local copies of outdated resource (and corresponding
+# metadata file).
+
 sub remove_stale_resfile {
     my ($url) = @_;
-    my $stale;
+    my $removed;
     if ($url=~m{^/res/($match_domain)/($match_username)/}) {
         my $audom = $1;
         my $auname = $2;
@@ -3194,12 +3231,32 @@ sub remove_stale_resfile {
                             my $remmodtime = &HTTP::Date::str2time( $response->header('Last-modified') );
                             my $locmodtime = (stat($fname))[9];
                             if ($locmodtime < $remmodtime) {
-                                unlink($fname);
-                                if ($uri!~/\.meta$/) {
-                                    unlink($fname.'.meta');
+                                my $stale;
+                                my $answer = &reply('pong',$homeserver);
+                                if ($answer eq $homeserver.':'.$perlvar{'lonHostID'}) {
+                                    sleep(0.2);
+                                    $locmodtime = (stat($fname))[9];
+                                    if ($locmodtime < $remmodtime) {
+                                        my $posstransfer = $fname.'.in.transfer';
+                                        if ((-e $posstransfer) && ($remmodtime < (stat($posstransfer))[9])) {
+                                            $removed = 1;
+                                        } else {
+                                            $stale = 1;
+                                        }
+                                    } else {
+                                        $removed = 1;
+                                    }
+                                } else {
+                                    $stale = 1;
+                                }
+                                if ($stale) {
+                                    unlink($fname);
+                                    if ($uri!~/\.meta$/) {
+                                        unlink($fname.'.meta');
+                                    }
+                                    &reply("unsub:$fname",$homeserver);
+                                    $removed = 1;
                                 }
-                                &reply("unsub:$fname",$homeserver);
-                                $stale = 1;
                             }
                         }
                     }
@@ -3207,7 +3264,7 @@ sub remove_stale_resfile {
             }
         }
     }
-    return $stale;
+    return $removed;
 }
 
 # -------------------------------- Allow a /uploaded/ URI to be vouched for
@@ -3559,7 +3616,7 @@ sub process_coursefile {
                                  $home);
             }
         } elsif ($action eq 'uploaddoc') {
-            open(my $fh,'>'.$filepath.'/'.$fname);
+            open(my $fh,'>',$filepath.'/'.$fname);
             print $fh $env{'form.'.$source};
             close($fh);
             if ($parser eq 'parse') {
@@ -3617,7 +3674,7 @@ sub store_edited_file {
     ($fpath,$fname) = ($file =~ m|^(.*)/([^/]+)$|);
     $fpath=$docudom.'/'.$docuname.'/'.$fpath;
     my $filepath = &build_filepath($fpath);
-    open(my $fh,'>'.$filepath.'/'.$fname);
+    open(my $fh,'>',$filepath.'/'.$fname);
     print $fh $content;
     close($fh);
     my $home=&homeserver($docuname,$docudom);
@@ -3768,7 +3825,7 @@ sub userfileupload {
                 mkdir($fullpath,0777);
             }
         }
-        open(my $fh,'>'.$fullpath.'/'.$fname);
+        open(my $fh,'>',$fullpath.'/'.$fname);
         print $fh $env{'form.'.$formname};
         close($fh);
         if ($context eq 'existingfile') {
@@ -3843,7 +3900,7 @@ sub finishuserfileupload {
 
 # Save the file
     {
-	if (!open(FH,'>'.$filepath.'/'.$file)) {
+	if (!open(FH,'>',$filepath.'/'.$file)) {
 	    &logthis('Failed to create '.$filepath.'/'.$file);
 	    print STDERR ('Failed to create '.$filepath.'/'.$file."\n");
 	    return '/adm/notfound.html';
@@ -3901,7 +3958,8 @@ sub finishuserfileupload {
         my $input = $filepath.'/'.$file;
         my $output = $filepath.'/'.'tn-'.$file;
         my $thumbsize = $thumbwidth.'x'.$thumbheight;
-        system("convert -sample $thumbsize $input $output");
+        my @args = ('convert','-sample',$thumbsize,$input,$output);
+        system({$args[0]} @args);
         if (-e $filepath.'/'.'tn-'.$file) {
             $fetchthumb  = 1; 
         }
@@ -4861,7 +4919,7 @@ sub postannounce {
 
 sub getannounce {
 
-    if (open(my $fh,$perlvar{'lonDocRoot'}.'/announcement.txt')) {
+    if (open(my $fh,"<",$perlvar{'lonDocRoot'}.'/announcement.txt')) {
 	my $announcement='';
 	while (my $line = <$fh>) { $announcement .= $line; }
 	close($fh);
@@ -7446,7 +7504,10 @@ sub allowed {
 # Free bre to public access
 
     if ($priv eq 'bre') {
-        my $copyright=&metadata($uri,'copyright');
+        my $copyright;
+        unless ($uri =~ /ext\.tool/) {
+            $copyright=&metadata($uri,'copyright');
+        }
 	if (($copyright eq 'public') && (!$env{'request.course.id'})) { 
            return 'F'; 
         }
@@ -8407,7 +8468,7 @@ sub fetch_enrollment_query {
                         if ($xml_classlist =~ /^error/) {
                             &logthis('fetch_enrollment_query - autoretrieve error: '.$xml_classlist.' for '.$filename.' from server: '.$homeserver.' '.$context.' '.$cnum);
                         } else {
-                            if ( open(FILE,">$destname") ) {
+                            if ( open(FILE,">",$destname) ) {
                                 print FILE &unescape($xml_classlist);
                                 close(FILE);
                             } else {
@@ -8436,7 +8497,7 @@ sub get_query_reply {
     for (1..$loopmax) {
 	sleep($sleep);
         if (-e $replyfile.'.end') {
-	    if (open(my $fh,$replyfile)) {
+	    if (open(my $fh,"<",$replyfile)) {
 		$reply = join('',<$fh>);
 		close($fh);
 	   } else { return 'error: reply_file_error'; }
@@ -10063,7 +10124,7 @@ sub save_selected_files {
     my ($user, $path, @files) = @_;
     my $filename = $user."savedfiles";
     my @other_files = &files_not_in_path($user, $path);
-    open (OUT, '>'.$tmpdir.$filename);
+    open (OUT,'>',LONCAPA::tempdir().$filename);
     foreach my $file (@files) {
         print (OUT $env{'form.currentpath'}.$file."\n");
     }
@@ -10077,7 +10138,7 @@ sub save_selected_files {
 sub clear_selected_files {
     my ($user) = @_;
     my $filename = $user."savedfiles";
-    open (OUT, '>'.LONCAPA::tempdir().$filename);
+    open (OUT,'>',LONCAPA::tempdir().$filename);
     print (OUT undef);
     close (OUT);
     return ("ok");    
@@ -10087,7 +10148,7 @@ sub files_in_path {
     my ($user, $path) = @_;
     my $filename = $user."savedfiles";
     my %return_files;
-    open (IN, '<'.LONCAPA::tempdir().$filename);
+    open (IN,'<',LONCAPA::tempdir().$filename);
     while (my $line_in = <IN>) {
         chomp ($line_in);
         my @paths_and_file = split (m!/!, $line_in);
@@ -10109,7 +10170,7 @@ sub files_not_in_path {
     my $filename = $user."savedfiles";
     my @return_files;
     my $path_part;
-    open(IN, '<'.LONCAPA::.$filename);
+    open(IN, '<',LONCAPA::tempdir().$filename);
     while (my $line = <IN>) {
         #ok, I know it's clunky, but I want it to work
         my @paths_and_file = split(m|/|, $line);
@@ -11094,33 +11155,40 @@ sub resdata {
     return undef;
 }
 
-sub get_domain_ltitools {
-    my ($cdom) = @_;
-    my %ltitools;
-    my ($result,$cached)=&is_cached_new('ltitools',$cdom);
+sub get_domain_lti {
+    my ($cdom,$context) = @_;
+    my ($name,%lti);
+    if ($context eq 'consumer') {
+        $name = 'ltitools';
+    } elsif ($context eq 'provider') {
+        $name = 'lti';
+    } else {
+        return %lti;
+    }
+    my ($result,$cached)=&is_cached_new($name,$cdom);
     if (defined($cached)) {
         if (ref($result) eq 'HASH') {
-            %ltitools = %{$result};
+            %lti = %{$result};
         }
     } else {
-        my %domconfig = &get_dom('configuration',['ltitools'],$cdom);
-        if (ref($domconfig{'ltitools'}) eq 'HASH') {
-            %ltitools = %{$domconfig{'ltitools'}};
-            my %encdomconfig = &get_dom('encconfig',['ltitools'],$cdom);
-            if (ref($encdomconfig{'ltitools'}) eq 'HASH') {
-                foreach my $id (keys(%ltitools)) {
-                    if (ref($encdomconfig{'ltitools'}{$id}) eq 'HASH') {
+        my %domconfig = &get_dom('configuration',[$name],$cdom);
+        if (ref($domconfig{$name}) eq 'HASH') {
+            %lti = %{$domconfig{$name}};
+            my %encdomconfig = &get_dom('encconfig',[$name],$cdom);
+            if (ref($encdomconfig{$name}) eq 'HASH') {
+                foreach my $id (keys(%lti)) {
+                    if (ref($encdomconfig{$name}{$id}) eq 'HASH') {
                         foreach my $item ('key','secret') {
-                            $ltitools{$id}{$item} = $encdomconfig{'ltitools'}{$id}{$item};
+                            $lti{$id}{$item} = $encdomconfig{$name}{$id}{$item};
                         }
                     }
                 }
             }
         }
         my $cachetime = 24*60*60;
-        &do_cache_new('ltitools',$cdom,\%ltitools,$cachetime);
+        &do_cache_new($name,$cdom,\%lti,$cachetime);
     }
-    return %ltitools;
+    return %lti;
 }
 
 sub get_numsuppfiles {
@@ -11426,9 +11494,13 @@ sub EXT {
 	} else {
 	    $filename=$env{'request.filename'};
 	}
-	my $metadata=&metadata($filename,$what);
+        my $toolsymb;
+        if (($filename =~ /ext\.tool$/) && ($what ne '0_gradable')) {
+            $toolsymb = $symbparm;
+        }
+	my $metadata=&metadata($filename,$what,$toolsymb);
 	if (defined($metadata)) { return &get_reply([$metadata,'resource']); }
-	$metadata=&metadata($filename,'parameter_'.$what);
+	$metadata=&metadata($filename,'parameter_'.$what,$toolsymb);
 	if (defined($metadata)) { return &get_reply([$metadata,'resource']); }
 
 # ----------------------------------------------- fifth, look in rest of course
@@ -11454,7 +11526,7 @@ sub EXT {
 	    if (defined($partgeneral[0])) { return &get_reply(\@partgeneral); }
 	}
 	if ($recurse) { return undef; }
-	my $pack_def=&packages_tab_default($filename,$varname);
+	my $pack_def=&packages_tab_default($filename,$varname,$toolsymb);
 	if (defined($pack_def)) { return &get_reply([$pack_def,'resource']); }
 # ---------------------------------------------------- Any other user namespace
     } elsif ($realm eq 'environment') {
@@ -11548,11 +11620,11 @@ sub sort_course_groups { # Sort groups b
 }
 
 sub packages_tab_default {
-    my ($uri,$varname)=@_;
+    my ($uri,$varname,$toolsymb)=@_;
     my (undef,$part,$name)=split(/\./,$varname);
 
     my (@extension,@specifics,$do_default);
-    foreach my $package (split(/,/,&metadata($uri,'packages'))) {
+    foreach my $package (split(/,/,&metadata($uri,'packages',$toolsymb))) {
 	my ($pack_type,$pack_part)=split(/_/,$package,2);
 	if ($pack_type eq 'default') {
 	    $do_default=1;
@@ -11620,7 +11692,7 @@ sub add_prefix_and_part {
 my %metaentry;
 my %importedpartids;
 sub metadata {
-    my ($uri,$what,$liburi,$prefix,$depthcount)=@_;
+    my ($uri,$what,$toolsymb,$liburi,$prefix,$depthcount)=@_;
     $uri=&declutter($uri);
     # if it is a non metadata possible uri return quickly
     if (($uri eq '') || 
@@ -11644,6 +11716,57 @@ sub metadata {
 	my ($result,$cached)=&is_cached_new('meta',$uri);
 	if (defined($cached)) { return $result->{':'.$what}; }
     }
+
+#
+# If the uri is for an external tool the file from
+# which metadata should be retrieved depends on whether
+# the tool had been configured to be gradable (set in the Course
+# Editor or Resource Editor).
+#
+# If a valid symb has been included as the third arg in the call
+# to &metadata() that can be used to retrieve the value of
+# parameter_0_gradable set for the resource, and included in the
+# uploaded map containing the tool. The value is retrieved via
+# &EXT(), if a valid symb is available.  Otherwise the value of
+# gradable in the exttool_$marker.db file for the tool instance
+# is retrived via &get().
+#
+# In order to avoid an infinite loop, &metadata() will return
+# before a call to &EXT(), if the uri is for an external tool
+# and the $what for which metadata is being requested is
+# parameter_0_gradable or 0_gradable.
+#
+
+    if ($uri =~ /ext\.tool$/) {
+        if (($what eq 'parameter_0_gradable') || ($what eq '0_gradable')) {
+            return;
+        } else {
+            my ($checked,$use_passback);
+            if ($toolsymb ne '') {
+                (undef,undef,my $tooluri) = &decode_symb($toolsymb);
+                if ($tooluri eq $uri) {
+                    $checked = 1;
+                    if (&EXT('resource.0.gradable',$toolsymb) =~ /^yes$/i) {
+                        $use_passback = 1;
+                    }
+                }
+            }
+            unless ($checked) {
+                my ($ignore,$cdom,$cnum,$marker) = split(m{/},$uri);
+                $marker=~s/\D//g;
+                if (!$marker) {
+                    my %toolsettings=&get('exttool_'.$marker,['gradable'],$cdom,$cnum);
+                    $use_passback = $toolsettings{'gradable'};
+                }
+            }
+            if ($use_passback) {
+                $filename = '/home/httpd/html/res/lib/templates/LTIpassback.tool';
+            } else {
+                $filename = '/home/httpd/html/res/lib/templates/LTIstandard.tool';
+            }
+        }
+    }
+
     {
 # Imported parts would go here
         my %importedids=();
@@ -11783,7 +11906,7 @@ sub metadata {
 
 			if ($depthcount<20) {
 			    my $metadata = 
-				&metadata($uri,'keys', $location,$unikey,
+				&metadata($uri,'keys',$toolsymb,$location,$unikey,
 					  $depthcount+1);
 			    foreach my $meta (split(',',$metadata)) {
 				$metaentry{':'.$meta}=$metaentry{':'.$meta};
@@ -11858,7 +11981,7 @@ sub metadata {
 		$dir=~s|[^/]*$||;
 		$location=&filelocation($dir,$location);
 		my $rights_metadata =
-		    &metadata($uri,'keys',$location,'_rights',
+		    &metadata($uri,'keys',$toolsymb,$location,'_rights',
 			      $depthcount+1);
 		foreach my $rights (split(',',$rights_metadata)) {
 		    #$metaentry{':'.$rights}=$metacache{$uri}->{':'.$rights};
@@ -12972,7 +13095,7 @@ sub readfile {
     my $file = shift;
     if ( (! -e $file ) || ($file eq '') ) { return -1; };
     my $fh;
-    open($fh,"<$file");
+    open($fh,"<",$file);
     my $a='';
     while (my $line = <$fh>) { $a .= $line; }
     return $a;
@@ -13085,7 +13208,7 @@ sub machine_ids {
 
 sub additional_machine_domains {
     my @domains;
-    open(my $fh,"<$perlvar{'lonTabDir'}/expected_domains.tab");
+    open(my $fh,"<","$perlvar{'lonTabDir'}/expected_domains.tab");
     while( my $line = <$fh>) {
         $line =~ s/\s//g;
         push(@domains,$line);
@@ -13231,7 +13354,7 @@ sub get_dns {
     }
 
     my %alldns;
-    open(my $config,"<$perlvar{'lonTabDir'}/hosts.tab");
+    open(my $config,"<","$perlvar{'lonTabDir'}/hosts.tab");
     foreach my $dns (<$config>) {
 	next if ($dns !~ /^\^(\S*)/x);
         my $line = $1;
@@ -13257,7 +13380,7 @@ sub get_dns {
     close($config);
     my $which = (split('/',$url))[3];
     &logthis("unable to contact DNS defaulting to on disk file dns_$which.tab\n");
-    open($config,"<$perlvar{'lonTabDir'}/dns_$which.tab");
+    open($config,"<","$perlvar{'lonTabDir'}/dns_$which.tab");
     my @content = <$config>;
     &$func(\@content,$hashref);
     return;
@@ -13350,7 +13473,7 @@ sub fetch_dns_checksums {
 	my ($ignore_cache,$nocache) = @_;
 	&get_dns('/adm/dns/domain',\&parse_domain_tab,$ignore_cache,$nocache);
 	my $fh;
-	if (open($fh,"<".$perlvar{'lonTabDir'}.'/domain.tab')) {
+	if (open($fh,"<",$perlvar{'lonTabDir'}.'/domain.tab')) {
 	    my @lines = <$fh>;
 	    &parse_domain_tab(\@lines);
 	}
@@ -13452,7 +13575,7 @@ sub fetch_dns_checksums {
     sub load_hosts_tab {
 	my ($ignore_cache,$nocache) = @_;
 	&get_dns('/adm/dns/hosts',\&parse_hosts_tab,$ignore_cache,$nocache);
-	open(my $config,"<$perlvar{'lonTabDir'}/hosts.tab");
+	open(my $config,"<","$perlvar{'lonTabDir'}/hosts.tab");
 	my @config = <$config>;
 	&parse_hosts_tab(\@config);
 	close($config);
@@ -13723,7 +13846,7 @@ sub all_loncaparevs {
 {
     sub load_loncaparevs { 
         if (-e "$perlvar{'lonTabDir'}/loncaparevs.tab") {
-            if (open(my $config,"<$perlvar{'lonTabDir'}/loncaparevs.tab")) {
+            if (open(my $config,"<","$perlvar{'lonTabDir'}/loncaparevs.tab")) {
                 while (my $configline=<$config>) {
                     chomp($configline);
                     my ($hostid,$loncaparev)=split(/:/,$configline);
@@ -13739,7 +13862,7 @@ sub all_loncaparevs {
 {
     sub load_serverhomeIDs {
         if (-e "$perlvar{'lonTabDir'}/serverhomeIDs.tab") {
-            if (open(my $config,"<$perlvar{'lonTabDir'}/serverhomeIDs.tab")) {
+            if (open(my $config,"<","$perlvar{'lonTabDir'}/serverhomeIDs.tab")) {
                 while (my $configline=<$config>) {
                     chomp($configline);
                     my ($name,$id)=split(/:/,$configline);
@@ -13764,7 +13887,7 @@ BEGIN {
 
 # ------------------------------------------------------ Read spare server file
 {
-    open(my $config,"<$perlvar{'lonTabDir'}/spare.tab");
+    open(my $config,"<","$perlvar{'lonTabDir'}/spare.tab");
 
     while (my $configline=<$config>) {
        chomp($configline);
@@ -13778,7 +13901,7 @@ BEGIN {
 }
 # ------------------------------------------------------------ Read permissions
 {
-    open(my $config,"<$perlvar{'lonTabDir'}/roles.tab");
+    open(my $config,"<","$perlvar{'lonTabDir'}/roles.tab");
 
     while (my $configline=<$config>) {
 	chomp($configline);
@@ -13792,7 +13915,7 @@ BEGIN {
 
 # -------------------------------------------- Read plain texts for permissions
 {
-    open(my $config,"<$perlvar{'lonTabDir'}/rolesplain.tab");
+    open(my $config,"<","$perlvar{'lonTabDir'}/rolesplain.tab");
 
     while (my $configline=<$config>) {
 	chomp($configline);
@@ -13812,7 +13935,7 @@ BEGIN {
 
 # ---------------------------------------------------------- Read package table
 {
-    open(my $config,"<$perlvar{'lonTabDir'}/packages.tab");
+    open(my $config,"<","$perlvar{'lonTabDir'}/packages.tab");
 
     while (my $configline=<$config>) {
 	if ($configline !~ /\S/ || $configline=~/^#/) { next; }
@@ -13866,7 +13989,7 @@ BEGIN {
 # ---------------------------------------------------------- Read managers table
 {
     if (-e "$perlvar{'lonTabDir'}/managers.tab") {
-        if (open(my $config,"<$perlvar{'lonTabDir'}/managers.tab")) {
+        if (open(my $config,"<","$perlvar{'lonTabDir'}/managers.tab")) {
             while (my $configline=<$config>) {
                 chomp($configline);
                 next if ($configline =~ /^\#/);
@@ -14605,10 +14728,14 @@ condval($condidx) : value of condition i
 
 =item *
 
-metadata($uri,$what,$liburi,$prefix,$depthcount) : request a
+metadata($uri,$what,$toolsymb,$liburi,$prefix,$depthcount) : request a
 resource's metadata, $what should be either a specific key, or either
 'keys' (to get a list of possible keys) or 'packages' to get a list of
-packages that this resource currently uses, the last 3 arguments are only used internally for recursive metadata.
+packages that this resource currently uses, the last 3 arguments are 
+only used internally for recursive metadata.
+
+the toolsymb is only used where the uri is for an external tool (for which
+the uri as well as the symb are guaranteed to be unique).
 
 this function automatically caches all requests