--- loncom/lonnet/perl/lonnet.pm	2000/09/26 20:07:24	1.32
+++ loncom/lonnet/perl/lonnet.pm	2000/10/09 20:26:17	1.40
@@ -28,18 +28,26 @@
 # restore            : returns hash for this url
 # eget(namesp,array) : returns hash with keys from array filled in from namesp
 # get(namesp,array)  : returns hash with keys from array filled in from namesp
-# del(namesp,array)  : deletes keys out of arry from namesp
+# del(namesp,array)  : deletes keys out of array from namesp
 # put(namesp,hash)   : stores hash in namesp
 # dump(namesp)       : dumps the complete namespace into a hash
 # ssi(url,hash)      : does a complete request cycle on url to localhost, posts
 #                      hash
+# coursedescription(id) : returns and caches course description for id
 # repcopy(filename)  : replicate file
 # dirlist(url)       : gets a directory listing
+# directcondval(index) : reading condition value of single condition from 
+#                        state string
 # condval(index)     : value of condition index based on state
 # varval(name)       : value of a variable
 # refreshstate()     : refresh the state information string
 # symblist(map,hash) : Updates symbolic storage links
+# symbread(filename) : returns the data handle
 # rndseed()          : returns a random seed  
+# getfile(filename)  : returns the contents of filename, or a -1 if it can't
+#                      be found, replicates and subscribes to the file
+# filelocation(dir,file) : returns a farily clean absolute reference to file 
+#                          from the directory dir
 #
 # 6/1/99,6/2,6/10,6/11,6/12,6/14,6/26,6/28,6/29,6/30,
 # 7/1,7/2,7/9,7/10,7/12,7/14,7/15,7/19,
@@ -51,7 +59,10 @@
 # 06/26 Ben Tyszka
 # 06/30,07/15,07/17,07/18,07/20,07/21,07/22,07/25 Gerd Kortemeyer
 # 08/14 Ben Tyszka
-# 08/22,08/28,08/31,09/01,09/02,09/04,09/05,09/25 Gerd Kortemeyer
+# 08/22,08/28,08/31,09/01,09/02,09/04,09/05,09/25,09/28,09/30 Gerd Kortemeyer
+# 10/04 Gerd Kortemeyer
+# 10/04 Guy Albertelli
+# 10/06,10/09 Gerd Kortemeyer
 
 package Apache::lonnet;
 
@@ -196,6 +207,15 @@ sub critical {
 
 sub appenv {
     my %newenv=@_;
+    map {
+	if (($newenv{$_}=~/^user\.role/) || ($newenv{$_}=~/^user\.priv/)) {
+            &logthis("<font color=blue>WARNING: ".
+                "Attempt to modify environment ".$_." to ".$newenv{$_});
+	    delete($newenv{$_});
+        } else {
+            $ENV{$_}=$newenv{$_};
+        }
+    } keys %newenv;
     my @oldenv;
     {
      my $fh;
@@ -411,12 +431,9 @@ sub log {
 sub store {
     my %storehash=@_;
     my $symb;
-    unless ($symb=escape(&symbread())) { return ''; }
+    unless ($symb=escape(&symbread($ENV{'request.filename'}))) { return ''; }
     my $namespace;
-    unless ($namespace=$ENV{'request.course.uri'}) { return ''; }
-    $namespace=~s/\//\_\_/g;
-    $namespace=~s/\./\_/g;
-    $namespace=escape($namespace);
+    unless ($namespace=$ENV{'request.course.id'}) { return ''; }
     my $namevalue='';
     map {
         $namevalue.=escape($_).'='.escape($storehash{$_}).'&';
@@ -431,12 +448,9 @@ sub store {
 
 sub restore {
     my $symb;
-    unless ($symb=escape(&symbread())) { return ''; }
+    unless ($symb=escape(&symbread($ENV{'request.filename'}))) { return ''; }
     my $namespace;
-    unless ($namespace=$ENV{'request.course.uri'}) { return ''; }
-    $namespace=~s/\//\_\_/g;
-    $namespace=~s/\./\_/g;
-    $namespace=escape($namespace);
+    unless ($namespace=$ENV{'request.course.id'}) { return ''; }
     my $answer=reply(
               "restore:$ENV{'user.domain'}:$ENV{'user.name'}:$namespace:$symb",
               "$ENV{'user.home'}");
@@ -451,6 +465,39 @@ sub restore {
     return %returnhash;
 }
 
+# ---------------------------------------------------------- Course Description
+
+sub coursedescription {
+    my $courseid=shift;
+    $courseid=~s/^\///;
+    my ($cdomain,$cnum)=split(/\//,$courseid);
+    my $chome=homeserver($cnum,$cdomain);
+    if ($chome ne 'no_host') {
+       my $rep=reply("dump:$cdomain:$cnum:environment",$chome);
+       if ($rep ne 'con_lost') {
+	   my %cachehash=();
+           my %returnhash=('home'   => $chome, 
+                           'domain' => $cdomain,
+                           'num'    => $cnum);
+           map {
+               my ($name,$value)=split(/\=/,$_);
+               $name=&unescape($name);
+               $value=&unescape($value);
+               $returnhash{$name}=$value;
+               if ($name eq 'description') {
+		   $cachehash{$courseid}=$value;
+               }
+           } split(/\&/,$rep);
+           $returnhash{'url'}='/res/'.declutter($returnhash{'url'});
+           $returnhash{'fn'}=$perlvar{'lonDaemons'}.'/tmp/'.
+	       $ENV{'user.name'}.'_'.$cdomain.'_'.$cnum;
+	   put ('coursedescriptions',%cachehash);
+           return %returnhash;
+       }
+    }
+    return ();
+}
+
 # -------------------------------------------------------- Get user priviledges
 
 sub rolesinit {
@@ -664,13 +711,13 @@ sub allowed {
 
    } else {
 
-       unless(defined($ENV{'request.course.uri'})) {
+       unless(defined($ENV{'request.course.id'})) {
 	   return '1';
        }
 
 # Get access priviledges for course
 
-       if ($ENV{'user.priv./'.$ENV{'request.course.uri'}}=~/$priv\&([^\:]*)/) {
+       if ($ENV{'user.priv./'.$ENV{'request.course.id'}}=~/$priv\&([^\:]*)/) {
           $thisallowed.=$1;
        }
 
@@ -683,7 +730,7 @@ sub allowed {
        $#uriparts--;
        my $uripath=join('/',@uriparts);
        my $uricond=-1;
-       if ($ENV{'acc.res.'.$ENV{'request.course'}.'.'.$uripath}=~
+       if ($ENV{'acc.res.'.$ENV{'request.course.id'}.'.'.$uripath}=~
 	   /\&$urifile\:(\d+)\&/) {
 	   $uricond=$1;
        } elsif (($fe{$uritype} eq 'emb') || ($fe{$uritype} eq 'img')) {
@@ -694,7 +741,7 @@ sub allowed {
           $urifile=$uriparts[$#uriparts];
           $#uriparts--;
           $uripath=join('/',@uriparts);
-          if ($ENV{'acc.res.'.$ENV{'request.course'}.'.'.$uripath}=~
+          if ($ENV{'acc.res.'.$ENV{'request.course.id'}.'.'.$uripath}=~
 	     /\&$urifile\:(\d+)\&/) {
 	     $uricond=$1;
 	  }
@@ -895,11 +942,20 @@ sub dirlist {
 
 # -------------------------------------------------------- Value of a Condition
 
+sub directcondval {
+    my $number=shift;
+    if ($ENV{'user.state.'.$ENV{'request.course.id'}}) {
+       return substr($ENV{'user.state.'.$ENV{'request.course.id'}},$number,1);
+    } else {
+       return 2;
+    }
+}
+
 sub condval {
     my $condidx=shift;
     my $result=0;
-    if ($ENV{'request.course'}) {
-       if (defined($ENV{'acc.cond.'.$ENV{'request.course'}.'.'.$condidx})) {
+    if ($ENV{'request.course.id'}) {
+       if (defined($ENV{'acc.cond.'.$ENV{'request.course.id'}.'.'.$condidx})) {
           my $operand='|';
 	  my @stack;
           map {
@@ -915,15 +971,14 @@ sub condval {
               } elsif (($_ eq '&') || ($_ eq '|')) {
                   $operand=$_;
               } else {
-                  my $new=
-                       substr($ENV{'user.state.'.$ENV{'request.course'}},$_,1);
+                  my $new=directcondval($_);
                   if ($operand eq '&') {
                      $result=$result>$new?$new:$result;
                   } else {
                      $result=$result>$new?$result:$new;
                   }                  
               }
-          } ($ENV{'acc.cond.'.$ENV{'request.course'}.'.'.$condidx}=~
+          } ($ENV{'acc.cond.'.$ENV{'request.course.id'}.'.'.$condidx}=~
              /(\d+|\(|\)|\&|\|)/g);
        }
     }
@@ -972,24 +1027,58 @@ sub symblist {
 # ------------------------------------------------------ Return symb list entry
 
 sub symbread {
+    my $thisfn=declutter(shift);
     my %hash;
-    my $syval;
+    my %bighash;
+    my $syval='';
     if (($ENV{'request.course.fn'}) && ($ENV{'request.filename'})) {
         if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
                       &GDBM_READER,0640)) {
-            my $thisfn=declutter($ENV{'request.filename'});
 	    $syval=$hash{$thisfn};
-            if (untie(%hash)) {
-                unless ($syval=~/\_\d+$/) {
-		   unless ($ENV{'form.request.prefix'}=~/\.(\d+)\_$/) {
-                      return '';
-                   }    
-                   $syval.=$1;
-	        }
-                $syval.='___'.$thisfn;
-		return $syval;
-            }
+            untie(%hash);
+        }
+# ---------------------------------------------------------- There was an entry
+        if ($syval) {
+           unless ($syval=~/\_\d+$/) {
+	       unless ($ENV{'form.request.prefix'}=~/\.(\d+)\_$/) {
+                  return '';
+               }    
+               $syval.=$1;
+	   }
+        } else {
+# ------------------------------------------------------- Was not in symb table
+           if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
+                            &GDBM_READER,0640)) {
+# ---------------------------------------------- Get ID(s) for current resource
+              my $ids=$bighash{'ids_/res/'.$thisfn};
+              if ($ids) {
+# ------------------------------------------------------------------- Has ID(s)
+                 my @possibilities=split(/\,/,$ids);
+                 if ($#possibilities==0) {
+# ----------------------------------------------- There is only one possibility
+		     my ($mapid,$resid)=split(/\./,$ids);
+                     $syval=declutter($bighash{'map_id_'.$mapid}).'___'.$resid;
+                 } else {
+# ------------------------------------------ There is more than one possibility
+                     my $realpossible=0;
+                     map {
+			 my $file=$bighash{'src_'.$_};
+                         if (&allowed('bre',$file)) {
+         		    my ($mapid,$resid)=split(/\./,$_);
+                            if ($bighash{'map_type_'.$mapid} ne 'page') {
+				$realpossible++;
+                                $syval=declutter($bighash{'map_id_'.$mapid}).
+                                       '___'.$resid;
+                            }
+			 }
+                     } @possibilities;
+		     if ($realpossible!=1) { $syval=''; }
+                 }
+	      }
+              untie(%bighash)
+           } 
         }
+        if ($syval) { return $syval.'___'.$thisfn; }
     }
     return '';
 }
@@ -1010,7 +1099,7 @@ sub numval {
 
 sub rndseed {
     my $symb;
-    unless ($symb=&symbread()) { return ''; }
+    unless ($symb=&symbread($ENV{'request.filename'})) { return ''; }
     my $symbchck=unpack("%32C*",$symb);
     my $symbseed=numval($symb)%$symbchck;
     my $namechck=unpack("%32C*",$ENV{'user.name'});
@@ -1018,11 +1107,40 @@ sub rndseed {
     return int( $symbseed
 	       .$nameseed
                .unpack("%32C*",$ENV{'user.domain'})
-               .unpack("%32C*",$ENV{'request.course.uri'})
+               .unpack("%32C*",$ENV{'request.course.id'})
                .$namechck
                .$symbchck);
 }
 
+# ------------------------------------------------------------ Serves up a file
+# returns either the contents of the file or a -1
+sub getfile {
+  my $file=shift;
+  &repcopy($file);
+  if (! -e $file ) { return -1; };
+  my $fh=Apache::File->new($file);
+  my $a='';
+  while (<$fh>) { $a .=$_; }
+  return $a
+}
+
+sub filelocation {
+  my ($dir,$file) = @_;
+  my $location;
+  $file=~ s/^\s*(\S+)\s*$/$1/; ## strip off leading and trailing spaces
+  $file=~s/^$perlvar{'lonDocRoot'}//;
+  $file=~s:^/*res::;
+  if ( !( $file =~ m:^/:) ) {
+    $location = $dir. '/'.$file;
+  } else {
+    $location = '/home/httpd/html/res'.$file;
+  }
+  $location=~s://+:/:g; # remove duplicate /
+  while ($location=~m:/../:) {$location=~ s:/[^/]+/\.\./:/:g;} #remove dir/..
+
+  return $location;
+}
+
 # ------------------------------------------------------------- Declutters URLs
 
 sub declutter {