--- loncom/lonnet/perl/lonnet.pm	2003/03/25 22:03:23	1.352
+++ loncom/lonnet/perl/lonnet.pm	2003/09/09 18:46:28	1.409
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.352 2003/03/25 22:03:23 www Exp $
+# $Id: lonnet.pm,v 1.409 2003/09/09 18:46:28 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -76,7 +76,9 @@ qw(%perlvar %hostname %homecache %badSer
    %libserv %pr %prp %metacache %packagetab %titlecache 
    %courselogs %accesshash %userrolehash $processmarker $dumpcount 
    %coursedombuf %coursenumbuf %coursehombuf %coursedescrbuf %courseresdatacache 
-   %domaindescription %domain_auth_def %domain_auth_arg_def $tmpdir);
+   %domaindescription %domain_auth_def %domain_auth_arg_def 
+   %domain_lang_def %domain_city %domain_longi %domain_lati $tmpdir);
+
 use IO::Socket;
 use GDBM_File;
 use Apache::Constants qw(:common :http);
@@ -244,6 +246,36 @@ sub critical {
     return $answer;
 }
 
+# -------------- Remove all key from the env that start witha lowercase letter
+#                (Which is alweways a lon-capa value)
+sub cleanenv {
+    foreach my $key (keys(%ENV)) {
+	if ($key =~ /^[a-z]/) {
+	    delete($ENV{$key});
+	}
+    }
+}
+ 
+# ------------------------------------------- Transfer profile into environment
+
+sub transfer_profile_to_env {
+    my ($lonidsdir,$handle)=@_;
+    my @profile;
+    {
+	my $idf=Apache::File->new("$lonidsdir/$handle.id");
+	flock($idf,LOCK_SH);
+	@profile=<$idf>;
+	$idf->close();
+    }
+    my $envi;
+    for ($envi=0;$envi<=$#profile;$envi++) {
+	chomp($profile[$envi]);
+	my ($envname,$envvalue)=split(/=/,$profile[$envi]);
+	$ENV{$envname} = $envvalue;
+    }
+    $ENV{'user.environment'} = "$lonidsdir/$handle.id";
+}
+
 # ---------------------------------------------------------- Append Environment
 
 sub appenv {
@@ -347,6 +379,30 @@ sub delenv {
     return 'ok';
 }
 
+# ------------------------------------------ Find out current server userload
+# there is a copy in lond
+sub userload {
+    my $numusers=0;
+    {
+	opendir(LONIDS,$perlvar{'lonIDsDir'});
+	my $filename;
+	my $curtime=time;
+	while ($filename=readdir(LONIDS)) {
+	    if ($filename eq '.' || $filename eq '..') {next;}
+	    my ($mtime)=(stat($perlvar{'lonIDsDir'}.'/'.$filename))[9];
+	    if ($curtime-$mtime < 3600) { $numusers++; }
+	}
+	closedir(LONIDS);
+    }
+    my $userloadpercent=0;
+    my $maxuserload=$perlvar{'lonUserLoadLim'};
+    if ($maxuserload) {
+	$userloadpercent=100*$numusers/$maxuserload;
+    }
+    $userloadpercent=sprintf("%.2f",$userloadpercent);
+    return $userloadpercent;
+}
+
 # ------------------------------------------ Fight off request when overloaded
 
 sub overloaderror {
@@ -373,17 +429,23 @@ sub overloaderror {
 # ------------------------------ Find server with least workload from spare.tab
 
 sub spareserver {
-    my $loadpercent = shift;
+    my ($loadpercent,$userloadpercent) = @_;
     my $tryserver;
     my $spareserver='';
-    my $lowestserver=$loadpercent; 
+    if ($userloadpercent !~ /\d/) { $userloadpercent=0; }
+    my $lowestserver=$loadpercent > $userloadpercent?
+	             $loadpercent :  $userloadpercent;
     foreach $tryserver (keys %spareid) {
-       my $answer=reply('load',$tryserver);
+       my $loadans=reply('load',$tryserver);
+       my $userloadans=reply('userload',$tryserver);
+       if ($userloadans !~ /\d/) { $userloadans=0; }
+       my $answer=$loadans > $userloadans?
+                  $loadans :  $userloadans;
        if (($answer =~ /\d/) && ($answer<$lowestserver)) {
 	   $spareserver="http://$hostname{$tryserver}";
            $lowestserver=$answer;
        }
-    }    
+    }
     return $spareserver;
 }
 
@@ -591,7 +653,11 @@ sub idput {
 # --------------------------------------------------- Assign a key to a student
 
 sub assign_access_key {
-    my ($ckey,$cdom,$cnum,$udom,$uname)=@_;
+#
+# a valid key looks like uname:udom#comments
+# comments are being appended
+#
+    my ($ckey,$cdom,$cnum,$udom,$uname,$logentry)=@_;
     $cdom=
    $ENV{'course.'.$ENV{'request.course.id'}.'.domain'} unless (defined($cdom));
     $cnum=
@@ -599,13 +665,16 @@ sub assign_access_key {
     $udom=$ENV{'user.name'} unless (defined($udom));
     $uname=$ENV{'user.domain'} unless (defined($uname));
     my %existing=&get('accesskeys',[$ckey],$cdom,$cnum);
-    if (($existing{$ckey}=~/^\d+$/) || # has time - new key
-        ($existing{$ckey} eq $uname.':'.$udom)) { # this should not happen,
+    if (($existing{$ckey}=~/^\#(.*)$/) || # - new key
+        ($existing{$ckey}=~/^$uname\:$udom\#(.*)$/)) { 
+                                                  # assigned to this person
+                                                  # - this should not happen,
                                                   # unless something went wrong
                                                   # the first time around
 # ready to assign
-    } elsif (!$existing{$ckey}) {
-        if (&put('accesskey',{$ckey=>$uname.':'.$udom},$cdom,$cnum) eq 'ok') {
+        $logentry=$1.'; '.$logentry;
+        if (&put('accesskey',{$ckey=>$uname.':'.$udom.'#'.$logentry},
+                                                 $cdom,$cnum) eq 'ok') {
 # key now belongs to user
 	    my $envkey='key.'.$cdom.'_'.$cnum;
             if (&put('environment',{$envkey => $ckey}) eq 'ok') {
@@ -618,6 +687,7 @@ sub assign_access_key {
         } else {
             return 'error: Could not assign key, try again later.';
         }
+    } elsif (!$existing{$ckey}) {
 # the key does not exist
 	return 'error: The key does not exist';
     } else {
@@ -626,15 +696,43 @@ sub assign_access_key {
     }
 }
 
+# ------------------------------------------ put an additional comment on a key
+
+sub comment_access_key {
+#
+# a valid key looks like uname:udom#comments
+# comments are being appended
+#
+    my ($ckey,$cdom,$cnum,$logentry)=@_;
+    $cdom=
+   $ENV{'course.'.$ENV{'request.course.id'}.'.domain'} unless (defined($cdom));
+    $cnum=
+   $ENV{'course.'.$ENV{'request.course.id'}.'.num'} unless (defined($cnum));
+    my %existing=&get('accesskeys',[$ckey],$cdom,$cnum);
+    if ($existing{$ckey}) {
+        $existing{$ckey}.='; '.$logentry;
+# ready to assign
+        if (&put('accesskeys',{$ckey=>$existing{$ckey}},
+                                                 $cdom,$cnum) eq 'ok') {
+	    return 'ok';
+        } else {
+	    return 'error: Count not store comment.';
+        }
+    } else {
+# the key does not exist
+	return 'error: The key does not exist';
+    }
+}
+
 # ------------------------------------------------------ Generate a set of keys
 
 sub generate_access_keys {
-    my ($number,$cdom,$cnum)=@_;
+    my ($number,$cdom,$cnum,$logentry)=@_;
     $cdom=
    $ENV{'course.'.$ENV{'request.course.id'}.'.domain'} unless (defined($cdom));
     $cnum=
    $ENV{'course.'.$ENV{'request.course.id'}.'.num'} unless (defined($cnum));
-    unless (&allowed('ccc',$cdom)) { return 0; }
+    unless (&allowed('mky',$cdom)) { return 0; }
     unless (($cdom) && ($cnum)) { return 0; }
     if ($number>10000) { return 0; }
     sleep(2); # make sure don't get same seed twice
@@ -650,7 +748,11 @@ sub generate_access_keys {
        if ($existing{$newkey}) {
            $i--;
        } else {
-	  if (&put('accesskeys',{ $newkey => time() },$cdom,$cnum) eq 'ok') {
+	  if (&put('accesskeys',
+              { $newkey => '# generated '.localtime().
+                           ' by '.$ENV{'user.name'}.'@'.$ENV{'user.domain'}.
+                           '; '.$logentry },
+		   $cdom,$cnum) eq 'ok') {
               $total++;
 	  }
        }
@@ -671,7 +773,7 @@ sub validate_access_key {
     $udom=$ENV{'user.name'} unless (defined($udom));
     $uname=$ENV{'user.domain'} unless (defined($uname));
     my %existing=&get('accesskeys',[$ckey],$cdom,$cnum);
-    return ($existing{$ckey} eq $uname.':'.$udom);
+    return ($existing{$ckey}=~/^$uname\:$udom\#/);
 }
 
 # ------------------------------------- Find the section of student in a course
@@ -892,9 +994,9 @@ sub repcopy {
 
 # ------------------------------------------------ Get server side include body
 sub ssi_body {
-    my $filelink=shift;
+    my ($filelink,%form)=@_;
     my $output=($filelink=~/^http\:/?&externalssi($filelink):
-                                     &ssi($filelink));
+                                     &ssi($filelink,%form));
     $output=~s/^.*\<body[^\>]*\>//si;
     $output=~s/\<\/body\s*\>.*$//si;
     $output=~
@@ -1069,7 +1171,7 @@ sub flushcourselogs {
 # Is used in pickcourse
 #
     foreach (keys %courseidbuffer) {
-        &reply('courseidput:'.$hostdom{$_}.':'.$courseidbuffer{$_},$_);
+        &courseidput($hostdom{$_},$courseidbuffer{$_},$_);
     }
 #
 # File accesses
@@ -1126,7 +1228,7 @@ sub courseacclog {
     my $fnsymb=shift;
     unless ($ENV{'request.course.id'}) { return ''; }
     my $what=$fnsymb.':'.$ENV{'user.name'}.':'.$ENV{'user.domain'};
-    if ($fnsymb=~/(problem|exam|quiz|assess|survey|form)$/) {
+    if ($fnsymb=~/(problem|exam|quiz|assess|survey|form|page)$/) {
         $what.=':POST';
 	foreach (keys %ENV) {
             if ($_=~/^form\.(.*)/) {
@@ -1149,6 +1251,14 @@ sub countacc {
     }
 }
 
+sub linklog {
+    my ($from,$to)=@_;
+    $from=&declutter($from);
+    $to=&declutter($to);
+    $accesshash{$from.'___'.$to.'___comefrom'}=1;
+    $accesshash{$to.'___'.$from.'___goto'}=1;
+}
+  
 sub userrolelog {
     my ($trole,$username,$domain,$area,$tstart,$tend)=@_;
     if (($trole=~/^ca/) || ($trole=~/^in/) || 
@@ -1182,9 +1292,88 @@ sub get_course_adv_roles {
         } else {
             $returnhash{$key}=$username.':'.$domain;
         }
+     }
+    return %returnhash;
+}
+
+sub get_my_roles {
+    my ($uname,$udom)=@_;
+    unless (defined($uname)) { $uname=$ENV{'user.name'}; }
+    unless (defined($udom)) { $udom=$ENV{'user.domain'}; }
+    my %dumphash=
+            &dump('nohist_userroles',$udom,$uname);
+    my %returnhash=();
+    my $now=time;
+    foreach (keys %dumphash) {
+	my ($tend,$tstart)=split(/\:/,$dumphash{$_});
+        if (($tstart) && ($tstart<0)) { next; }
+        if (($tend) && ($tend<$now)) { next; }
+        if (($tstart) && ($now<$tstart)) { next; }
+        my ($role,$username,$domain,$section)=split(/\:/,$_);
+	$returnhash{$username.':'.$domain.':'.$role}=$tstart.':'.$tend;
+     }
+    return %returnhash;
+}
+
+# ----------------------------------------------------- Frontpage Announcements
+#
+#
+
+sub postannounce {
+    my ($server,$text)=@_;
+    unless (&allowed('psa',$hostdom{$server})) { return 'refused'; }
+    unless ($text=~/\w/) { $text=''; }
+    return &reply('setannounce:'.&escape($text),$server);
+}
+
+sub getannounce {
+    if (my $fh=Apache::File->new($perlvar{'lonDocRoot'}.'/announcement.txt')) {
+	my $announcement='';
+	while (<$fh>) { $announcement .=$_; }
+	$fh->close();
+	if ($announcement=~/\w/) { 
+	    return 
+   '<table bgcolor="#FF5555" cellpadding="5" cellspacing="3">'.
+   '<tr><td bgcolor="#FFFFFF"><pre>'.$announcement.'</pre></td></tr></table>'; 
+	} else {
+	    return '';
+	}
+    } else {
+	return '';
+    }
+}
+
+# ---------------------------------------------------------- Course ID routines
+# Deal with domain's nohist_courseid.db files
+#
+
+sub courseidput {
+    my ($domain,$what,$coursehome)=@_;
+    return &reply('courseidput:'.$domain.':'.$what,$coursehome);
+}
+
+sub courseiddump {
+    my ($domfilter,$descfilter,$sincefilter)=@_;
+    my %returnhash=();
+    unless ($domfilter) { $domfilter=''; }
+    foreach my $tryserver (keys %libserv) {
+	if ((!$domfilter) || ($hostdom{$tryserver} eq $domfilter)) {
+	    foreach (
+             split(/\&/,&reply('courseiddump:'.$hostdom{$tryserver}.':'.
+			       $sincefilter.':'.&escape($descfilter),
+                               $tryserver))) {
+		my ($key,$value)=split(/\=/,$_);
+                if (($key) && ($value)) {
+		    $returnhash{&unescape($key)}=&unescape($value);
+                }
+            }
+
+        }
     }
-    return sort %returnhash;
+    return %returnhash;
 }
+
+#
 # ----------------------------------------------------------- Check out an item
 
 sub checkout {
@@ -1295,19 +1484,19 @@ sub devalidate {
     my ($symb,$uname,$udom)=@_;
     my $cid=$ENV{'request.course.id'}; 
     if ($cid) {
-# delete the stored spreadsheets for
-# - the student level sheet of this user in course's homespace
-# - the assessment level sheet for this resource 
-#   for this user in user's homespace
+        # delete the stored spreadsheets for
+        # - the student level sheet of this user in course's homespace
+        # - the assessment level sheet for this resource 
+        #   for this user in user's homespace
 	my $key=$uname.':'.$udom.':';
         my $status=
 	    &del('nohist_calculatedsheets',
-		 [$key.'studentcalc'],
+		 [$key.'studentcalc:'],
 		 $ENV{'course.'.$cid.'.domain'},
 		 $ENV{'course.'.$cid.'.num'})
 		.' '.
 	    &del('nohist_calculatedsheets_'.$cid,
-		 [$key.'assesscalc:'.$symb]);
+		 [$key.'assesscalc:'.$symb],$udom,$uname);
         unless ($status eq 'ok ok') {
            &logthis('Could not devalidate spreadsheet '.
                     $uname.' at '.$udom.' for '.
@@ -1513,7 +1702,7 @@ sub tmpreset {
   my ($symb,$namespace,$domain,$stuname) = @_;
   if (!$symb) {
     $symb=&symbread();
-    if (!$symb) { $symb= $ENV{'REQUEST_URI'}; }
+    if (!$symb) { $symb= $ENV{'request.url'}; }
   }
   $symb=escape($symb);
 
@@ -1806,14 +1995,14 @@ sub rolesinit {
 		my ($tdummy,$tdomain,$trest)=split(/\//,$area);
 		if ($trole =~ /^cr\//) {
 		    my ($rdummy,$rdomain,$rauthor,$rrole)=split(/\//,$trole);
-		    my $homsvr=homeserver($rauthor,$rdomain);
+ 		    my $homsvr=homeserver($rauthor,$rdomain);
 		    if ($hostname{$homsvr} ne '') {
-			my $roledef=
-			    reply("get:$rdomain:$rauthor:roles:rolesdef_$rrole",
-				  $homsvr);
-			if (($roledef ne 'con_lost') && ($roledef ne '')) {
+			my ($rdummy,$roledef)=
+			   &get('roles',["rolesdef_$rrole"],$rdomain,$rauthor);
+				
+			if (($rdummy ne 'con_lost') && ($roledef ne '')) {
 			    my ($syspriv,$dompriv,$coursepriv)=
-				split(/\_/,unescape($roledef));
+				split(/\_/,$roledef);
 			    if (defined($syspriv)) {
 				$allroles{'cm./'}.=':'.$syspriv;
 				$allroles{$spec.'./'}.=':'.$syspriv;
@@ -1947,6 +2136,21 @@ sub dump {
    return %returnhash;
 }
 
+# -------------------------------------------------------------- keys interface
+
+sub getkeys {
+   my ($namespace,$udomain,$uname)=@_;
+   if (!$udomain) { $udomain=$ENV{'user.domain'}; }
+   if (!$uname) { $uname=$ENV{'user.name'}; }
+   my $uhome=&homeserver($uname,$udomain);
+   my $rep=reply("keys:$udomain:$uname:$namespace",$uhome);
+   my @keyarray=();
+   foreach (split(/\&/,$rep)) {
+      push (@keyarray,&unescape($_));
+   }
+   return @keyarray;
+}
+
 # --------------------------------------------------------------- currentdump
 sub currentdump {
    my ($courseid,$sdom,$sname)=@_;
@@ -2079,6 +2283,9 @@ sub customaccess {
             $access=($effect eq 'allow');
             last;
         }
+	if ($realm eq '' && $role eq '') {
+            $access=($effect eq 'allow');
+	}
     }
     return $access;
 }
@@ -2091,6 +2298,7 @@ sub allowed {
     my $orguri=$uri;
     $uri=&declutter($uri);
 
+    if (defined($ENV{'allowed.'.$priv})) { return $ENV{'allowed.'.$priv}; }
 # Free bre access to adm and meta resources
 
     if ((($uri=~/^adm\//) || ($uri=~/\.meta$/)) && ($priv eq 'bre')) {
@@ -2391,7 +2599,7 @@ sub is_on_map {
 sub definerole {
   if (allowed('mcr','/')) {
     my ($rolename,$sysrole,$domrole,$courole)=@_;
-    foreach (split('/',$sysrole)) {
+    foreach (split(':',$sysrole)) {
 	my ($crole,$cqual)=split(/\&/,$_);
         if ($pr{'cr:s'}!~/$crole/) { return "refused:s:$crole"; }
         if ($pr{'cr:s'}=~/$crole\&/) {
@@ -2400,7 +2608,7 @@ sub definerole {
             }
         }
     }
-    foreach (split('/',$domrole)) {
+    foreach (split(':',$domrole)) {
 	my ($crole,$cqual)=split(/\&/,$_);
         if ($pr{'cr:d'}!~/$crole/) { return "refused:d:$crole"; }
         if ($pr{'cr:d'}=~/$crole\&/) {
@@ -2409,7 +2617,7 @@ sub definerole {
             }
         }
     }
-    foreach (split('/',$courole)) {
+    foreach (split(':',$courole)) {
 	my ($crole,$cqual)=split(/\&/,$_);
         if ($pr{'cr:c'}!~/$crole/) { return "refused:c:$crole"; }
         if ($pr{'cr:c'}=~/$crole\&/) {
@@ -2518,10 +2726,12 @@ sub plaintext {
 # ----------------------------------------------------------------- Assign Role
 
 sub assignrole {
-    my ($udom,$uname,$url,$role,$end,$start)=@_;
+    my ($udom,$uname,$url,$role,$end,$start,$deleteflag)=@_;
     my $mrole;
     if ($role =~ /^cr\//) {
-	unless (&allowed('ccr',$url)) {
+        my $cwosec=$url;
+        $cwosec=~s/^\/(\w+)\/(\w+)\/.*/$1\/$2/;
+	unless (&allowed('ccr',$cwosec)) {
            &logthis('Refused custom assignrole: '.
              $udom.' '.$uname.' '.$url.' '.$role.' '.$end.' '.$start.' by '.
 		    $ENV{'user.name'}.' at '.$ENV{'user.domain'});
@@ -2531,7 +2741,7 @@ sub assignrole {
     } else {
         my $cwosec=$url;
         $cwosec=~s/^\/(\w+)\/(\w+)\/.*/$1\/$2/;
-        unless (&allowed('c'.$role,$cwosec)) { 
+        unless ((&allowed('c'.$role,$cwosec)) || &allowed('c'.$role,$udom)) { 
            &logthis('Refused assignrole: '.
              $udom.' '.$uname.' '.$url.' '.$role.' '.$end.' '.$start.' by '.
 		    $ENV{'user.name'}.' at '.$ENV{'user.domain'});
@@ -2549,7 +2759,21 @@ sub assignrole {
            $command.='_0_'.$start;
         }
     }
+# actually delete
+    if ($deleteflag) {
+	if ((&allowed('dro',$udom)) || (&allowed('dro',$url))) {
+# modify command to delete the role
+           $command="encrypt:rolesdel:$ENV{'user.domain'}:$ENV{'user.name'}:".
+                "$udom:$uname:$url".'_'."$mrole";
+	   &logthis("$ENV{'user.name'} at $ENV{'user.domain'} deletes $mrole in $url for $uname at $udom"); 
+# set start and finish to negative values for userrolelog
+           $start=-1;
+           $end=-1;
+        }
+    }
+# send command
     my $answer=&reply($command,&homeserver($uname,$udom));
+# log new user role if status is ok
     if ($answer eq 'ok') {
 	&userrolelog($mrole,$uname,$udom,$url,$start,$end);
     }
@@ -2588,7 +2812,7 @@ sub modifyuser {
     my ($udom,    $uname, $uid,
         $umode,   $upass, $first,
         $middle,  $last,  $gene,
-        $forceid, $desiredhome)=@_;
+        $forceid, $desiredhome, $email)=@_;
     $udom=~s/\W//g;
     $uname=~s/\W//g;
     &logthis('Call to modify user '.$udom.', '.$uname.', '.$uid.', '.
@@ -2600,7 +2824,8 @@ sub modifyuser {
              ' in domain '.$ENV{'request.role.domain'});
     my $uhome=&homeserver($uname,$udom,'true');
 # ----------------------------------------------------------------- Create User
-    if (($uhome eq 'no_host') && ($umode) && ($upass)) {
+    if (($uhome eq 'no_host') && 
+	(($umode && $upass) || ($umode eq 'localauth'))) {
         my $unhome='';
         if (defined($desiredhome) && $hostdom{$desiredhome} eq $udom) { 
             $unhome = $desiredhome;
@@ -2630,7 +2855,7 @@ sub modifyuser {
         }   
         $uhome=&homeserver($uname,$udom,'true');
         if (($uhome eq '') || ($uhome eq 'no_host') || ($uhome ne $unhome)) {
-	    return 'error: verify home';
+	    return 'error: unable verify users home machine.';
         }
     }   # End of creation of new user
 # ---------------------------------------------------------------------- Add ID
@@ -2640,7 +2865,8 @@ sub modifyuser {
        if (($uidhash{$uname}) && ($uidhash{$uname}!~/error\:/) 
          && (!$forceid)) {
 	  unless ($uid eq $uidhash{$uname}) {
-	      return 'error: mismatch '.$uidhash{$uname}.' versus '.$uid;
+	      return 'error: user id "'.$uid.'" does not match '.
+                  'current user id "'.$uidhash{$uname}.'".';
           }
        } else {
 	  &idput($udom,($uname => $uid));
@@ -2656,10 +2882,17 @@ sub modifyuser {
     } else {
         %names = @tmp;
     }
+#
+# Make sure to not trash student environment if instructor does not bother
+# to supply name and email information
+#
     if ($first)  { $names{'firstname'}  = $first; }
-    if ($middle) { $names{'middlename'} = $middle; }
+    if (defined($middle)) { $names{'middlename'} = $middle; }
     if ($last)   { $names{'lastname'}   = $last; }
-    if ($gene)   { $names{'generation'} = $gene; }
+    if (defined($gene))   { $names{'generation'} = $gene; }
+    if ($email)  { $names{'notification'} = $email;
+                   $names{'critnotification'} = $email; }
+
     my $reply = &put('environment', \%names, $udom,$uname);
     if ($reply ne 'ok') { return 'error: '.$reply; }
     &logthis('Success modifying user '.$udom.', '.$uname.', '.$uid.', '.
@@ -2673,7 +2906,7 @@ sub modifyuser {
 
 sub modifystudent {
     my ($udom,$uname,$uid,$umode,$upass,$first,$middle,$last,$gene,$usec,
-        $end,$start,$forceid,$desiredhome)=@_;
+        $end,$start,$forceid,$desiredhome,$email)=@_;
     my $cid='';
     unless ($cid=$ENV{'request.course.id'}) {
 	return 'not_in_class';
@@ -2681,7 +2914,7 @@ sub modifystudent {
 # --------------------------------------------------------------- Make the user
     my $reply=&modifyuser
 	($udom,$uname,$uid,$umode,$upass,$first,$middle,$last,$gene,$forceid,
-         $desiredhome);
+         $desiredhome,$email);
     unless ($reply eq 'ok') { return $reply; }
     # This will cause &modify_student_enrollment to get the uid from the
     # students environment
@@ -2799,6 +3032,11 @@ sub createcourse {
 	return 'error: no such course';
     }
 # ----------------------------------------------------------------- Course made
+# log existance
+    &courseidput($udom,&escape($udom.'_'.$uname).'='.&escape($description),
+                 $uhome);
+    &flushcourselogs();
+# set toplevel url
     my $topurl=$url;
     unless ($nonstandard) {
 # ------------------------------------------ For standard courses, make top url
@@ -2827,25 +3065,26 @@ ENDINITMAP
 # ---------------------------------------------------------- Assign Custom Role
 
 sub assigncustomrole {
-    my ($udom,$uname,$url,$rdom,$rnam,$rolename,$end,$start)=@_;
+    my ($udom,$uname,$url,$rdom,$rnam,$rolename,$end,$start,$deleteflag)=@_;
     return &assignrole($udom,$uname,$url,'cr/'.$rdom.'/'.$rnam.'/'.$rolename,
-                       $end,$start);
+                       $end,$start,$deleteflag);
 }
 
 # ----------------------------------------------------------------- Revoke Role
 
 sub revokerole {
-    my ($udom,$uname,$url,$role)=@_;
+    my ($udom,$uname,$url,$role,$deleteflag)=@_;
     my $now=time;
-    return &assignrole($udom,$uname,$url,$role,$now);
+    return &assignrole($udom,$uname,$url,$role,$now,$deleteflag);
 }
 
 # ---------------------------------------------------------- Revoke Custom Role
 
 sub revokecustomrole {
-    my ($udom,$uname,$url,$rdom,$rnam,$rolename)=@_;
+    my ($udom,$uname,$url,$rdom,$rnam,$rolename,$deleteflag)=@_;
     my $now=time;
-    return &assigncustomrole($udom,$uname,$url,$rdom,$rnam,$rolename,$now);
+    return &assigncustomrole($udom,$uname,$url,$rdom,$rnam,$rolename,$now,
+           $deleteflag);
 }
 
 # ------------------------------------------------------------ Directory lister
@@ -2910,7 +3149,7 @@ sub dirlist {
         }
         my $alldomstr='';
         foreach (sort keys %alldom) {
-            $alldomstr.=$perlvar{'lonDocRoot'}.'/res/'.$_.'&domain:';
+            $alldomstr.=$perlvar{'lonDocRoot'}.'/res/'.$_.'/&domain:';
         }
         $alldomstr=~s/:$//;
         return split(/:/,$alldomstr);       
@@ -2934,12 +3173,12 @@ sub GetFileTimestamp {
     $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
     my $proname="$studentDomain/$subdir/$studentName";
     $proname .= '/'.$filename;
-    my @dir = &Apache::lonnet::dirlist($proname, $studentDomain, $studentName,
-                                       $root);
-    my $fileStat = $dir[0];
+    my ($fileStat) = &Apache::lonnet::dirlist($proname, $studentDomain, 
+                                              $studentName, $root);
     my @stats = split('&', $fileStat);
     if($stats[0] ne 'empty' && $stats[0] ne 'no_such_dir') {
-        return $stats[9];
+        # @stats contains first the filename, then the stat output
+        return $stats[10]; # so this is 10 instead of 9.
     } else {
         return -1;
     }
@@ -3035,16 +3274,42 @@ sub courseresdata {
     return undef;
 }
 
-# --------------------------------------------------------- Value of a Variable
+#
+# EXT resource caching routines
+#
+
+sub clear_EXT_cache_status {
+    &delenv('cache.EXT.');
+}
+
+sub EXT_cache_status {
+    my ($target_domain,$target_user) = @_;
+    my $cachename = 'cache.EXT.'.$target_user.'.'.$target_domain;
+    if (exists($ENV{$cachename}) && ($ENV{$cachename}+600) > time) {
+        # We know already the user has no data
+        return 1;
+    } else {
+        return 0;
+    }
+}
 
+sub EXT_cache_set {
+    my ($target_domain,$target_user) = @_;
+    my $cachename = 'cache.EXT.'.$target_user.'.'.$target_domain;
+    &appenv($cachename => time);
+}
+
+# --------------------------------------------------------- Value of a Variable
 sub EXT {
-    my ($varname,$symbparm,$udom,$uname,)=@_;
+    my ($varname,$symbparm,$udom,$uname,$usection,$recurse)=@_;
 
     unless ($varname) { return ''; }
     #get real user name/domain, courseid and symb
     my $courseid;
+    my $publicuser;
     if (!($uname && $udom)) {
-      (my $cursymb,$courseid,$udom,$uname)=&Apache::lonxml::whichuser();
+      (my $cursymb,$courseid,$udom,$uname,$publicuser)=
+	  &Apache::lonxml::whichuser($symbparm);
       if (!$symbparm) {	$symbparm=$cursymb; }
     } else {
 	$courseid=$ENV{'request.course.id'};
@@ -3067,7 +3332,12 @@ sub EXT {
 	    if (defined($Apache::lonhomework::parsing_a_problem)) {
 		return $Apache::lonhomework::history{$qualifierrest};
 	    } else {
-		my %restored=&restore($symbparm,$courseid,$udom,$uname);
+		my %restored;
+		if ($publicuser || $ENV{'request.state'} eq 'construct') {
+		    %restored=&tmprestore($symbparm,$courseid,$udom,$uname);
+		} else {
+		    %restored=&restore($symbparm,$courseid,$udom,$uname);
+		}
 		return $restored{$qualifierrest};
 	    }
 # ----------------------------------------------------------------- user.access
@@ -3080,7 +3350,11 @@ sub EXT {
 		($udom eq $ENV{'user.domain'})) {
 		return $ENV{join('.',('environment',$qualifierrest))};
 	    } else {
-		my %returnhash=&userenvironment($udom,$uname,$qualifierrest);
+		my %returnhash;
+		if (!$publicuser) {
+		    %returnhash=&userenvironment($udom,$uname,
+						 $qualifierrest);
+		}
 		return $returnhash{$qualifierrest};
 	    }
 # ----------------------------------------------------------------- user.course
@@ -3104,13 +3378,17 @@ sub EXT {
             return $uname;
 # ---------------------------------------------------- Any other user namespace
         } else {
-            my %reply=&get($space,[$qualifierrest],$udom,$uname);
-            return $reply{$qualifierrest};
+	    my %reply;
+	    if (!$publicuser) {
+		%reply=&get($space,[$qualifierrest],$udom,$uname);
+	    }
+	    return $reply{$qualifierrest};
         }
     } elsif ($realm eq 'query') {
 # ---------------------------------------------- pull stuff out of query string
-        &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},[$space]);
-	return $ENV{'form.'.$space}; 
+        &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
+						[$spacequalifierrest]);
+	return $ENV{'form.'.$spacequalifierrest}; 
    } elsif ($realm eq 'request') {
 # ------------------------------------------------------------- request.browser
         if ($space eq 'browser') {
@@ -3124,24 +3402,28 @@ sub EXT {
         return $ENV{'course.'.$courseid.'.'.$spacequalifierrest};
     } elsif ($realm eq 'resource') {
 
-	if ($courseid eq $ENV{'request.course.id'}) {
+	my $section;
+	if (defined($courseid) && $courseid eq $ENV{'request.course.id'}) {
 
 	    #print '<br>'.$space.' - '.$qualifier.' - '.$spacequalifierrest;
 
 # ----------------------------------------------------- Cascading lookup scheme
 	    if (!$symbparm) { $symbparm=&symbread(); }
 	    my $symbp=$symbparm;
-	    my $mapp=(split(/\_\_\_/,$symbp))[0];
+	    my $mapp=(&decode_symb($symbp))[0];
 
 	    my $symbparm=$symbp.'.'.$spacequalifierrest;
 	    my $mapparm=$mapp.'___(all).'.$spacequalifierrest;
 
-	    my $section;
 	    if (($ENV{'user.name'} eq $uname) &&
 		($ENV{'user.domain'} eq $udom)) {
 		$section=$ENV{'request.course.sec'};
 	    } else {
-		$section=&usection($udom,$uname,$courseid);
+                if (! defined($usection)) {
+                    $section=&usection($udom,$uname,$courseid);
+                } else {
+                    $section = $usection;
+                }
 	    }
 
 	    my $seclevel=$courseid.'.['.$section.'].'.$spacequalifierrest;
@@ -3153,11 +3435,9 @@ sub EXT {
 	    my $courselevelm=$courseid.'.'.$mapparm;
 
 # ----------------------------------------------------------- first, check user
-	    #most student don't have any data set, check if there is some data
+	    #most student don\'t have any data set, check if there is some data
             #every thirty minutes
-	    if (!
-		(exists($ENV{'cache.studentresdata'})
-		    && (($ENV{'cache.studentresdata'}+1800) > time))) {
+	    if (! &EXT_cache_status($udom,$uname)) {
 		my %resourcedata=&get('resourcedata',
 				      [$courselevelr,$courselevelm,$courselevel],
 				      $udom,$uname);
@@ -3176,9 +3456,7 @@ sub EXT {
 				 $uname." at ".$udom.": ".
 				 $tmp."</font>");
 		    } elsif ($tmp=~/error:No such file/) {
-			$ENV{'cache.studentresdata'}=time;
-			&appenv(('cache.studentresdata'=>
-				 $ENV{'cache.studentresdata'}));
+                        &EXT_cache_set($udom,$uname);
 		    } elsif ($tmp =~ /^(con_lost|no_such_host)/) {
 			return $tmp;
 		    }
@@ -3211,7 +3489,7 @@ sub EXT {
 	my $filename;
 	if (!$symbparm) { $symbparm=&symbread(); }
 	if ($symbparm) {
-	    $filename=(split(/\_\_\_/,$symbparm))[2];
+	    $filename=(&decode_symb($symbparm))[2];
 	} else {
 	    $filename=$ENV{'request.filename'};
 	}
@@ -3227,9 +3505,12 @@ sub EXT {
 	    my $part=join('_',@parts);
 	    if ($part eq '') { $part='0'; }
 	    my $partgeneral=&EXT('resource.'.$part.'.'.$qualifierrest,
-				 $symbparm,$udom,$uname);
+				 $symbparm,$udom,$uname,$section,1);
 	    if (defined($partgeneral)) { return $partgeneral; }
 	}
+	if ($recurse) { return undef; }
+	my $pack_def=&packages_tab_default($filename,$varname);
+	if (defined($pack_def)) { return $pack_def; }
 
 # ---------------------------------------------------- Any other user namespace
     } elsif ($realm eq 'environment') {
@@ -3250,6 +3531,19 @@ sub EXT {
     return '';
 }
 
+sub packages_tab_default {
+    my ($uri,$varname)=@_;
+    my (undef,$part,$name)=split(/\./,$varname);
+    my $packages=&metadata($uri,'packages');
+    foreach my $package (split(/,/,$packages)) {
+	my ($pack_type,$pack_part)=split(/_/,$package,2);
+	if ($pack_part eq $part) {
+	    return $packagetab{"$pack_type&$name&default"};
+	}
+    }
+    return undef;
+}
+
 sub add_prefix_and_part {
     my ($prefix,$part)=@_;
     my $keyroot;
@@ -3291,7 +3585,9 @@ sub metadata {
         if ($liburi) {
 	    $liburi=&declutter($liburi);
             $filename=$liburi;
-        }
+        } else {
+	    delete($metacache{$uri.':packages'});
+	}
         my %metathesekeys=();
         unless ($filename=~/\.meta$/) { $filename.='.meta'; }
 	my $metastring=&getfile(&filelocation('',&clutter($filename)));
@@ -3317,6 +3613,9 @@ sub metadata {
 		    foreach (keys %packagetab) {
 			if ($_=~/^$package\&/) {
 			    my ($pack,$name,$subp)=split(/\&/,$_);
+			    # ignore package.tab specified default values
+                            # here &package_tab_default() will fetch those
+			    if ($subp eq 'default') { next; }
 			    my $value=$packagetab{$_};
 			    my $part=$keyroot;
 			    $part=~s/^\_//;
@@ -3324,16 +3623,15 @@ sub metadata {
 				$value.=' [Part: '.$part.']';
 			    }
 			    my $unikey='parameter'.$keyroot.'_'.$name;
-			    if ($subp eq 'default') { $unikey='parameter_0_'.$name; }
-			    $metathesekeys{$unikey}=1;
 			    $metacache{$uri.':'.$unikey.'.part'}=$part;
+			    $metathesekeys{$unikey}=1;
 			    unless (defined($metacache{$uri.':'.$unikey.'.'.$subp})) {
 				$metacache{$uri.':'.$unikey.'.'.$subp}=$value;
 			    }
 			    if (defined($metacache{$uri.':'.$unikey.'.default'})) {
 				$metacache{$uri.':'.$unikey}=
-				    $metacache{$uri.':'.$unikey.'.default'}
-				}
+				    $metacache{$uri.':'.$unikey.'.default'};
+			    }
 			}
 		    }
 		} else {
@@ -3429,7 +3727,7 @@ sub metadata_generate_part0 {
 	if ($metakey=~/^parameter\_(.*)/) {
 	  my $part=$$metacache{$uri.':'.$metakey.'.part'};
 	  my $name=$$metacache{$uri.':'.$metakey.'.name'};
-	  if (! exists($$metadata{'parameter_0_'.$name})) {
+	  if (! exists($$metadata{'parameter_0_'.$name.'.name'})) {
 	    $allnames{$name}=$part;
 	  }
 	}
@@ -3459,8 +3757,14 @@ sub gettitle {
 	unless ($urlsymb) { $urlsymb=$ENV{'request.filename'}; }
         return &metadata($urlsymb,'title'); 
     }
-    if ($titlecache{$symb}) { return $titlecache{$symb}; }
-    my ($map,$resid,$url)=split(/\_\_\_/,$symb);
+    if ($titlecache{$symb}) {
+	if (time < ($titlecache{$symb}[1] + 600)) {
+	    return $titlecache{$symb}[0];
+	} else {
+	    delete($titlecache{$symb});
+	}
+    }
+    my ($map,$resid,$url)=&decode_symb($symb);
     my $title='';
     my %bighash;
     if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
@@ -3469,8 +3773,9 @@ sub gettitle {
         $title=$bighash{'title_'.$mapid.'.'.$resid};
         untie %bighash;
     }
+    $title=~s/\&colon\;/\:/gs;
     if ($title) {
-        $titlecache{$symb}=$title;
+        $titlecache{$symb}=[$title,time];
         return $title;
     } else {
 	return &metadata($urlsymb,'title');
@@ -3505,7 +3810,7 @@ sub symbverify {
 # direct jump to resource in page or to a sequence - will construct own symbs
     if ($thisfn=~/\.(page|sequence)$/) { return 1; }
 # check URL part
-    my ($map,$resid,$url)=split(/\_\_\_/,$symb);
+    my ($map,$resid,$url)=&decode_symb($symb);
     unless (&symbclean($url) eq &symbclean($thisfn)) { return 0; }
 
     $symb=&symbclean($symb);
@@ -3548,6 +3853,12 @@ sub symbclean {
     return $symb;
 }
 
+# ---------------------------------------------- Split symb to find map and url
+
+sub decode_symb {
+    return split(/\_\_\_/,shift);
+}
+
 # ------------------------------------------------------ Return symb list entry
 
 sub symbread {
@@ -3642,29 +3953,92 @@ sub numval {
     $txt=~tr/u-z/0-5/;
     $txt=~s/\D//g;
     return int($txt);
-}    
+}
+
+sub latest_rnd_algorithm_id {
+    return '64bit';
+}
 
 sub rndseed {
     my ($symb,$courseid,$domain,$username)=@_;
+
+    my ($wsymb,$wcourseid,$wdomain,$wusername)=&Apache::lonxml::whichuser();
     if (!$symb) {
-      unless ($symb=&symbread()) { return time; }
+	unless ($symb=$wsymb) { return time; }
+    }
+    if (!$courseid) { $courseid=$wcourseid; }
+    if (!$domain) { $domain=$wdomain; }
+    if (!$username) { $username=$wusername }
+    my $which=$ENV{"course.$courseid.rndseed"};
+    my $CODE=$ENV{'scantron.CODE'};
+    if (defined($CODE)) {
+	&rndseed_CODE_64bit($symb,$courseid,$domain,$username);
+    } elsif ($which eq '64bit') {
+	return &rndseed_64bit($symb,$courseid,$domain,$username);
     }
-    if (!$courseid) { $courseid=$ENV{'request.course.id'};}
-    if (!$domain) {$domain=$ENV{'user.domain'};}
-    if (!$username) {$username=$ENV{'user.name'};}
+    return &rndseed_32bit($symb,$courseid,$domain,$username);
+}
+
+sub rndseed_32bit {
+    my ($symb,$courseid,$domain,$username)=@_;
+    {
+	use integer;
+	my $symbchck=unpack("%32C*",$symb) << 27;
+	my $symbseed=numval($symb) << 22;
+	my $namechck=unpack("%32C*",$username) << 17;
+	my $nameseed=numval($username) << 12;
+	my $domainseed=unpack("%32C*",$domain) << 7;
+	my $courseseed=unpack("%32C*",$courseid);
+	my $num=$symbseed+$nameseed+$domainseed+$courseseed+$namechck+$symbchck;
+	#&Apache::lonxml::debug("$symbseed:$nameseed;$domainseed|$courseseed;$namechck:$symbchck");
+	#&Apache::lonxml::debug("rndseed :$num:$symb");
+	return $num;
+    }
+}
+
+sub rndseed_64bit {
+    my ($symb,$courseid,$domain,$username)=@_;
     {
-      use integer;
-      my $symbchck=unpack("%32C*",$symb) << 27;
-      my $symbseed=numval($symb) << 22;
-      my $namechck=unpack("%32C*",$username) << 17;
-      my $nameseed=numval($username) << 12;
-      my $domainseed=unpack("%32C*",$domain) << 7;
-      my $courseseed=unpack("%32C*",$courseid);
-      my $num=$symbseed+$nameseed+$domainseed+$courseseed+$namechck+$symbchck;
-      #uncommenting these lines can break things!
-      #&Apache::lonxml::debug("$symbseed:$nameseed;$domainseed|$courseseed;$namechck:$symbchck");
-      #&Apache::lonxml::debug("rndseed :$num:$symb");
-      return $num;
+	use integer;
+	my $symbchck=unpack("%32S*",$symb) << 21;
+	my $symbseed=numval($symb) << 10;
+	my $namechck=unpack("%32S*",$username);
+	
+	my $nameseed=numval($username) << 21;
+	my $domainseed=unpack("%32S*",$domain) << 10;
+	my $courseseed=unpack("%32S*",$courseid);
+	
+	my $num1=$symbchck+$symbseed+$namechck;
+	my $num2=$nameseed+$domainseed+$courseseed;
+	#&Apache::lonxml::debug("$symbseed:$nameseed;$domainseed|$courseseed;$namechck:$symbchck");
+	#&Apache::lonxml::debug("rndseed :$num:$symb");
+	return "$num1,$num2";
+    }
+}
+
+sub rndseed_CODE_64bit {
+    my ($symb,$courseid,$domain,$username)=@_;
+    {
+	use integer;
+	my $symbchck=unpack("%32S*",$symb) << 16;
+	my $symbseed=numval($symb);
+	my $CODEseed=numval($ENV{'scantron.CODE'}) << 16;
+	my $courseseed=unpack("%32S*",$courseid);
+	my $num1=$symbseed+$CODEseed;
+	my $num2=$courseseed+$symbchck;
+	#&Apache::lonxml::debug("$symbseed:$CODEseed|$courseseed:$symbchck");
+	#&Apache::lonxml::debug("rndseed :$num1:$num2:$symb");
+	return "$num1,$num2";
+    }
+}
+
+sub setup_random_from_rndseed {
+    my ($rndseed)=@_;
+    if ($rndseed =~/,/) {
+	my ($num1,$num2)=split(/,/,$rndseed);
+	&Math::Random::random_set_seed(abs($num1),abs($num2));
+    } else {
+	&Math::Random::random_set_seed_from_phrase($rndseed);
     }
 }
 
@@ -3790,6 +4164,7 @@ sub goodbye {
    &logthis("Starting Shut down");
    &flushcourselogs();
    &logthis("Shutting down");
+   return DONE;
 }
 
 BEGIN {
@@ -3827,13 +4202,19 @@ BEGIN {
     %domain_auth_arg_def = ();
     if ($fh) {
        while (<$fh>) {
-           next if /^\#/;
+           next if (/^(\#|\s*$)/);
+#           next if /^\#/;
            chomp;
-           my ($domain, $domain_description, $def_auth, $def_auth_arg)
-               = split(/:/,$_,4);
-           $domain_auth_def{$domain}=$def_auth;
+           my ($domain, $domain_description, $def_auth, $def_auth_arg,
+	       $def_lang, $city, $longi, $lati) = split(/:/,$_);
+	   $domain_auth_def{$domain}=$def_auth;
            $domain_auth_arg_def{$domain}=$def_auth_arg;
-           $domaindescription{$domain}=$domain_description;
+	   $domaindescription{$domain}=$domain_description;
+	   $domain_lang_def{$domain}=$def_lang;
+	   $domain_city{$domain}=$city;
+	   $domain_longi{$domain}=$longi;
+	   $domain_lati{$domain}=$lati;
+
 #          &logthis("Domain.tab: $domain, $domain_auth_def{$domain}, $domain_auth_arg_def{$domain},$domaindescription{$domain}");
 #          &logthis("Domain.tab: $domain ".$domaindescription{$domain} );
        }
@@ -3970,45 +4351,125 @@ being set.
 
 =back
 
-=head1 INTRODUCTION
+=head1 OVERVIEW
 
-This module provides subroutines which interact with the
-lonc/lond (TCP) network layer of LON-CAPA. And Can be used to ask about 
-- classes
-- users 
-- resources
+lonnet provides subroutines which interact with the
+lonc/lond (TCP) network layer of LON-CAPA. They can be used to ask
+about classes, users, and resources.
 
 For many of these objects you can also use this to store data about
 them or modify them in various ways.
 
-This is part of the LearningOnline Network with CAPA project
-described at http://www.lon-capa.org.
+=head2 Symbs
 
-=head1 RETURN MESSAGES
+To identify a specific instance of a resource, LON-CAPA uses symbols
+or "symbs"X<symb>. These identifiers are built from the URL of the
+map, the resource number of the resource in the map, and the URL of
+the resource itself. The latter is somewhat redundant, but might help
+if maps change.
 
-=over 4
+An example is
 
-=item *
+ msu/korte/parts/part1.sequence___19___msu/korte/tests/part12.problem
 
-con_lost : unable to contact remote host
+The respective map entry is
 
-=item *
+ <resource id="19" src="/res/msu/korte/tests/part12.problem"
+  title="Problem 2">
+ </resource>
 
-con_delayed : unable to contact remote host, message will be delivered
-when the connection is brought back up
+Symbs are used by the random number generator, as well as to store and
+restore data specific to a certain instance of for example a problem.
 
-=item *
+=head2 Storing And Retrieving Data
 
-con_failed : unable to contact remote host and unable to save message
-for later delivery
+X<store()>X<cstore()>X<restore()>Three of the most important functions
+in C<lonnet.pm> are C<&Apache::lonnet::cstore()>,
+C<&Apache::lonnet:restore()>, and C<&Apache::lonnet::store()>, which
+is is the non-critical message twin of cstore. These functions are for
+handlers to store a perl hash to a user's permanent data space in an
+easy manner, and to retrieve it again on another call. It is expected
+that a handler would use this once at the beginning to retrieve data,
+and then again once at the end to send only the new data back.
 
-=item *
+The data is stored in the user's data directory on the user's
+homeserver under the ID of the course.
 
-error: : an error a occured, a description of the error follows the :
+The hash that is returned by restore will have all of the previous
+value for all of the elements of the hash.
 
-=item *
+Example:
+
+ #creating a hash
+ my %hash;
+ $hash{'foo'}='bar';
+
+ #storing it
+ &Apache::lonnet::cstore(\%hash);
+
+ #changing a value
+ $hash{'foo'}='notbar';
+
+ #adding a new value
+ $hash{'bar'}='foo';
+ &Apache::lonnet::cstore(\%hash);
+
+ #retrieving the hash
+ my %history=&Apache::lonnet::restore();
+
+ #print the hash
+ foreach my $key (sort(keys(%history))) {
+   print("\%history{$key} = $history{$key}");
+ }
+
+Will print out:
+
+ %history{1:foo} = bar
+ %history{1:keys} = foo:timestamp
+ %history{1:timestamp} = 990455579
+ %history{2:bar} = foo
+ %history{2:foo} = notbar
+ %history{2:keys} = foo:bar:timestamp
+ %history{2:timestamp} = 990455580
+ %history{bar} = foo
+ %history{foo} = notbar
+ %history{timestamp} = 990455580
+ %history{version} = 2
+
+Note that the special hash entries C<keys>, C<version> and
+C<timestamp> were added to the hash. C<version> will be equal to the
+total number of versions of the data that have been stored. The
+C<timestamp> attribute will be the UNIX time the hash was
+stored. C<keys> is available in every historical section to list which
+keys were added or changed at a specific historical revision of a
+hash.
+
+B<Warning>: do not store the hash that restore returns directly. This
+will cause a mess since it will restore the historical keys as if the
+were new keys. I.E. 1:foo will become 1:1:foo etc.
+
+Calling convention:
 
-no_such_host : unable to fund a host associated with the user/domain
+ my %record=&Apache::lonnet::restore($symb,$courseid,$domain,$uname,$home);
+ &Apache::lonnet::cstore(\%newrecord,$symb,$courseid,$domain,$uname,$home);
+
+For more detailed information, see lonnet specific documentation.
+
+=head1 RETURN MESSAGES
+
+=over 4
+
+=item * B<con_lost>: unable to contact remote host
+
+=item * B<con_delayed>: unable to contact remote host, message will be delivered
+when the connection is brought back up
+
+=item * B<con_failed>: unable to contact remote host and unable to save message
+for later delivery
+
+=item * B<error:>: an error a occured, a description of the error follows the :
+
+=item * B<no_such_host>: unable to fund a host associated with the user/domain
 that was requested
 
 =back
@@ -4019,15 +4480,18 @@ that was requested
 
 =over 4
 
-=item *
-
-appenv(%hash) : the value of %hash is written to the user envirnoment
-file, and will be restored for each access this user makes during this
-session, also modifies the %ENV for the current process
+=item * 
+X<appenv()>
+B<appenv(%hash)>: the value of %hash is written to
+the user envirnoment file, and will be restored for each access this
+user makes during this session, also modifies the %ENV for the current
+process
 
 =item *
-
-delenv($regexp) : removes all items from the session environment file that matches the regular expression in $regexp. The values are also delted from the current processes %ENV.
+X<delenv()>
+B<delenv($regexp)>: removes all items from the session
+environment file that matches the regular expression in $regexp. The
+values are also delted from the current processes %ENV.
 
 =back
 
@@ -4036,50 +4500,51 @@ delenv($regexp) : removes all items from
 =over 4
 
 =item *
-
-queryauthenticate($uname,$udom) : try to determine user's current
+X<queryauthenticate()>
+B<queryauthenticate($uname,$udom)>: try to determine user's current 
 authentication scheme
 
 =item *
-
-authenticate($uname,$upass,$udom) : try to authenticate user from domain's lib
-servers (first use the current one), $upass should be the users password
+X<authenticate()>
+B<authenticate($uname,$upass,$udom)>: try to
+authenticate user from domain's lib servers (first use the current
+one). C<$upass> should be the users password.
 
 =item *
-
-homeserver($uname,$udom) : find the server which has the user's
-directory and files (there must be only one), this caches the answer,
-and also caches if there is a borken connection.
+X<homeserver()>
+B<homeserver($uname,$udom)>: find the server which has
+the user's directory and files (there must be only one), this caches
+the answer, and also caches if there is a borken connection.
 
 =item *
-
-idget($udom,@ids) : find the usernames behind a list of IDs (IDs are a
-unique resource in a domain, there must be only 1 ID per username, and
-only 1 username per ID in a specific domain) (returns hash:
-id=>name,id=>name)
+X<idget()>
+B<idget($udom,@ids)>: find the usernames behind a list of IDs
+(IDs are a unique resource in a domain, there must be only 1 ID per
+username, and only 1 username per ID in a specific domain) (returns
+hash: id=>name,id=>name)
 
 =item *
-
-idrget($udom,@unames) : find the IDs behind a list of usernames (returns hash:
-name=>id,name=>id)
+X<idrget()>
+B<idrget($udom,@unames)>: find the IDs behind a list of
+usernames (returns hash: name=>id,name=>id)
 
 =item *
-
-idput($udom,%ids) : store away a list of names and associated IDs
+X<idput()>
+B<idput($udom,%ids)>: store away a list of names and associated IDs
 
 =item *
-
-rolesinit($udom,$username,$authhost) : get user privileges
+X<rolesinit()>
+B<rolesinit($udom,$username,$authhost)>: get user privileges
 
 =item *
-
-usection($udom,$uname,$cname) : finds the section of student in the
+X<usection()>
+B<usection($udom,$uname,$cname)>: finds the section of student in the
 course $cname, return section name/number or '' for "not in course"
 and '-1' for "no section"
 
 =item *
-
-userenvironment($udom,$uname,@what) : gets the values of the keys
+X<userenvironment()>
+B<userenvironment($udom,$uname,@what)>: gets the values of the keys
 passed in @what from the requested user's environment, returns a hash
 
 =back