--- loncom/lonnet/perl/lonnet.pm	2017/10/16 16:33:54	1.1357
+++ loncom/lonnet/perl/lonnet.pm	2018/03/23 01:02:04	1.1368
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1357 2017/10/16 16:33:54 raeburn Exp $
+# $Id: lonnet.pm,v 1.1368 2018/03/23 01:02:04 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($dfh);
 		}
@@ -707,6 +707,7 @@ sub check_for_valid_session {
     if (ref($userhashref) eq 'HASH') {
         $userhashref->{'name'} = $disk_env{'user.name'};
         $userhashref->{'domain'} = $disk_env{'user.domain'};
+        $userhashref->{'lti'} = $disk_env{'request.lti.login'};
     }
 
     return $handle;
@@ -3615,7 +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') {
@@ -3673,7 +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,$docudom);
@@ -3824,7 +3825,7 @@ sub userfileupload {
                 mkdir($fullpath,0777);
             }
         }
-        open(my $fh,'>'.$fullpath.'/'.$fname);
+        open(my $fh,'>',$fullpath.'/'.$fname);
         print $fh $env{'form.'.$formname};
         close($fh);
         if ($context eq 'existingfile') {
@@ -3899,7 +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';
@@ -3957,7 +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; 
         }
@@ -4917,7 +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);
@@ -5227,6 +5229,9 @@ sub set_first_access {
                         'course.'.$courseid.'.timerinterval.'.$res => $interval,
                      }
                   );
+            if (($cachedtime) && (abs($start-$cachedtime) < 5)) {
+                $cachedtimes{"$courseid\0$res"} = $start;
+            }
         }
         return $putres;
     }
@@ -7141,6 +7146,7 @@ sub usertools_access {
                       community  => 1,
                       textbook   => 1,
                       placement  => 1,
+                      lti        => 1,
                  );
     } elsif ($context eq 'requestauthor') {
         %tools = (
@@ -7337,25 +7343,29 @@ sub is_advanced_user {
 }
 
 sub check_can_request {
-    my ($dom,$can_request,$request_domains) = @_;
+    my ($dom,$can_request,$request_domains,$uname,$udom) = @_;
     my $canreq = 0;
+    if (($env{'user.name'} ne '') && ($env{'user.domain'} ne '')) {
+        $uname = $env{'user.name'};
+        $udom = $env{'user.domain'};
+    }
     my ($types,$typename) = &Apache::loncommon::course_types();
     my @options = ('approval','validate','autolimit');
     my $optregex = join('|',@options);
     if ((ref($can_request) eq 'HASH') && (ref($types) eq 'ARRAY')) {
         foreach my $type (@{$types}) {
-            if (&usertools_access($env{'user.name'},
-                                  $env{'user.domain'},
-                                  $type,undef,'requestcourses')) {
+            if (&usertools_access($uname,$udom,$type,undef,
+                                  'requestcourses')) {
                 $canreq ++;
                 if (ref($request_domains) eq 'HASH') {
-                    push(@{$request_domains->{$type}},$env{'user.domain'});
+                    push(@{$request_domains->{$type}},$udom);
                 }
-                if ($dom eq $env{'user.domain'}) {
+                if ($dom eq $udom) {
                     $can_request->{$type} = 1;
                 }
             }
-            if ($env{'environment.reqcrsotherdom.'.$type} ne '') {
+            if (($env{'user.name'} ne '') && ($env{'user.domain'} ne '') &&
+                ($env{'environment.reqcrsotherdom.'.$type} ne '')) {
                 my @curr = split(',',$env{'environment.reqcrsotherdom.'.$type});
                 if (@curr > 0) {
                     foreach my $item (@curr) {
@@ -7372,7 +7382,7 @@ sub check_can_request {
                             }
                         }
                     }
-                    unless($dom eq $env{'user.domain'}) {
+                    unless ($dom eq $env{'user.domain'}) {
                         $canreq ++;
                         if (grep(/^\Q$dom\E:($optregex)(=?\d*)$/,@curr)) {
                             $can_request->{$type} = 1;
@@ -7502,7 +7512,10 @@ 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'; 
         }
@@ -8463,7 +8476,7 @@ 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($xml_classlist);
                                 close(FILE);
                             } else {
@@ -8492,7 +8505,7 @@ sub get_query_reply {
     for (1..$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'; }
@@ -8884,6 +8897,33 @@ sub auto_validate_class_sec {
     return $response;
 }
 
+sub auto_validate_instclasses {
+    my ($cdom,$cnum,$owners,$classesref) = @_;
+    my ($homeserver,%validations);
+    $homeserver = &homeserver($cnum,$cdom);
+    unless ($homeserver eq 'no_host') {
+        my $ownerlist;
+        if (ref($owners) eq 'ARRAY') {
+            $ownerlist = join(',',@{$owners});
+        } else {
+            $ownerlist = $owners;
+        }
+        if (ref($classesref) eq 'HASH') {
+            my $classes = &freeze_escape($classesref);
+            my $response=&reply('autovalidateinstclasses:'.&escape($ownerlist).
+                                ':'.$cdom.':'.$classes,$homeserver);
+            unless ($response =~ /(con_lost|error|no_such_host|refused)/) {
+                my @items = split(/&/,$response);
+                foreach my $item (@items) {
+                    my ($key,$value) = split('=',$item);
+                    $validations{&unescape($key)} = &thaw_unescape($value);
+                }
+            }
+        }
+    }
+    return %validations;
+}
+
 sub auto_crsreq_update {
     my ($cdom,$cnum,$crstype,$action,$ownername,$ownerdomain,$fullname,$title,
         $code,$accessstart,$accessend,$inbound) = @_;
@@ -9263,8 +9303,12 @@ sub assignrole {
                             }
                         }
                     }
-                } elsif (($selfenroll == 1) && ($role eq 'st') && ($udom eq $env{'user.domain'}) && ($uname eq $env{'user.name'})) {
-                    $refused = '';
+                } elsif (($selfenroll == 1) && ($udom eq $env{'user.domain'}) && ($uname eq $env{'user.name'})) {
+                    if ($role eq 'st') {
+                        $refused = '';
+                    } elsif (($context eq 'ltienroll') && ($env{'request.lti'})) {
+                        $refused = '';
+                    }
                 } elsif ($context eq 'requestcourses') {
                     my @possroles = ('st','ta','ep','in','cc','co');
                     if ((grep(/^\Q$role\E$/,@possroles)) && ($env{'user.name'} ne '' && $env{'user.domain'} ne '')) {
@@ -9530,10 +9574,14 @@ sub modifyuser {
     my $newuser;
     if ($uhome eq 'no_host') {
         $newuser = 1;
+        unless (($umode && ($upass ne '')) || ($umode eq 'localauth') ||
+                ($umode eq 'lti')) {
+            return 'error: more information needed to create new user';
+        }
     }
 # ----------------------------------------------------------------- Create User
     if (($uhome eq 'no_host') && 
-	(($umode && $upass) || ($umode eq 'localauth'))) {
+	(($umode && $upass) || ($umode eq 'localauth') || ($umode eq 'lti'))) {
         my $unhome='';
         if (defined($desiredhome) && &host_domain($desiredhome) eq $udom) { 
             $unhome = $desiredhome;
@@ -10119,7 +10167,7 @@ sub save_selected_files {
     my ($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");
     }
@@ -10133,7 +10181,7 @@ sub save_selected_files {
 sub clear_selected_files {
     my ($user) = @_;
     my $filename = $user."savedfiles";
-    open (OUT, '>'.LONCAPA::tempdir().$filename);
+    open (OUT,'>',LONCAPA::tempdir().$filename);
     print (OUT undef);
     close (OUT);
     return ("ok");    
@@ -10143,7 +10191,7 @@ sub files_in_path {
     my ($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);
@@ -10165,7 +10213,7 @@ 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);
@@ -11150,33 +11198,40 @@ 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 {
@@ -11189,10 +11244,11 @@ sub get_numsuppfiles {
     unless (defined($cached)) {
         my $chome=&homeserver($cnum,$cdom);
         unless ($chome eq 'no_host') {
-            ($suppcount,my $errors) = (0,0);
+            ($suppcount,my $supptools,my $errors) = (0,0,0);
             my $suppmap = 'supplemental.sequence';
-            ($suppcount,$errors) = 
-                &Apache::loncommon::recurse_supplemental($cnum,$cdom,$suppmap,$suppcount,$errors);
+            ($suppcount,$supptools,$errors) =
+                &Apache::loncommon::recurse_supplemental($cnum,$cdom,$suppmap,$suppcount,
+                                                         $supptools,$errors);
         }
         &do_cache_new('suppcount',$hashid,$suppcount,600);
     }
@@ -11482,9 +11538,13 @@ 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
@@ -11510,7 +11570,7 @@ 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') {
@@ -11604,11 +11664,11 @@ 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') {
 	    $do_default=1;
@@ -11676,7 +11736,7 @@ sub add_prefix_and_part {
 my %metaentry;
 my %importedpartids;
 sub metadata {
-    my ($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 (($uri eq '') || 
@@ -11700,6 +11760,65 @@ sub metadata {
 	my ($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_$marker.db file for the tool instance
+# is retrieved via &get().
+#
+# When lonuserstate::traceroute() calls lonnet::EXT() for 
+# hiddenresource and encrypturl (during course initialization)
+# the map-level parameter for resource.0.gradable included in the 
+# uploaded map containing the tool will not yet have been stored
+# in the user_course_parms.db file for the user's session, so in 
+# this case fall back to retrieving gradable status from the
+# exttool_$marker.db file.
+#
+# 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 $uri) && (&EXT('resource.0.gradable',$toolsymb))) {
+                    $checked = 1;
+                    if (&EXT('resource.0.gradable',$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=();
@@ -11839,7 +11958,7 @@ 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};
@@ -11914,7 +12033,7 @@ 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};
@@ -13028,7 +13147,7 @@ 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;
@@ -13141,7 +13260,7 @@ 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);
@@ -13287,7 +13406,7 @@ 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 = $1;
@@ -13313,7 +13432,7 @@ sub get_dns {
     close($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;
@@ -13406,7 +13525,7 @@ 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);
 	}
@@ -13508,7 +13627,7 @@ 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);
@@ -13779,7 +13898,7 @@ 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);
@@ -13795,7 +13914,7 @@ 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);
@@ -13820,7 +13939,7 @@ 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);
@@ -13834,7 +13953,7 @@ BEGIN {
 }
 # ------------------------------------------------------------ Read permissions
 {
-    open(my $config,"<$perlvar{'lonTabDir'}/roles.tab");
+    open(my $config,"<","$perlvar{'lonTabDir'}/roles.tab");
 
     while (my $configline=<$config>) {
 	chomp($configline);
@@ -13848,7 +13967,7 @@ 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);
@@ -13868,7 +13987,7 @@ 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/ || $configline=~/^#/) { next; }
@@ -13922,7 +14041,7 @@ BEGIN {
 # ---------------------------------------------------------- Read managers table
 {
     if (-e "$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 =~ /^\#/);
@@ -14661,10 +14780,14 @@ 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