--- loncom/cgi/thumbnail.gif	2002/05/29 20:57:16	1.1
+++ loncom/cgi/thumbnail.gif	2005/04/07 06:56:21	1.4
@@ -25,33 +25,85 @@
 #
 # http://www.lon-capa.org/
 #
-# Scott Harrison
-# YEAR=2001
-# 8/15,9/28,12/11
-#
 ###
 
 # Example usage: /cgi-bin/thumbnail.gif?url=...
 
+
 use strict;
 
+sub filelocation {
+  my ($dir,$file) = @_;
+  my $location;
+  $file=~ s/^\s*(\S+)\s*$/$1/; ## strip off leading and trailing spaces
+  if ($file=~m:^/~:) { # is a contruction space reference
+    $location = $file;
+    $location =~ s:/~(.*?)/(.*):/home/$1/public_html/$2:;
+  } else {
+    $file=~s/\/home\/httpd\/html//;
+    $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;
+}
+
+my %env;
+
 $|=1;   # Autoflush after each print/write
 foreach (split(/&/,$ENV{'QUERY_STRING'})) {
     my ($name, $value) = split(/=/,$_);
     $value =~ tr/+/ /;
     $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
     if ($name eq 'url') {
-	$ENV{'form.'.$name}=$value;
+	$env{'form.'.$name}=$value;
     }
 }
 
+
+my $ofn=&filelocation('',$env{'form.url'});
+my $fn=$ofn.'.thumbnail';
+
+my $exists=1;
+my $generate=0;
+
+if (-e $ofn) {
+   my ($dev,$ino,$mode,$nlink,
+       $uid,$gid,$rdev,$size,
+       $atime,$omtime,$ctime,
+       $blksize,$blocks)=stat($ofn);
+   if (-e $fn) {
+       my ($dev,$ino,$mode,$nlink,
+           $uid,$gid,$rdev,$size,
+           $atime,$mtime,$ctime,
+           $blksize,$blocks)=stat($fn);
+       if ($omtime>$mtime) { $generate=1; }
+   } else {
+       $generate=1;
+   }
+} else {
+    $exists=0;
+}
+
+# FIXME: generate thumbnail instead
+if ($generate) { $exists=0; }
+
+
+unless ($exists) {
+   $fn='/home/httpd/html/res/adm/pages/nothumb.gif';
+}
+
 # Tell the server we are sending a gif graphic
 print <<END;
 Content-type: image/gif
 
 END
 
-my $fn='/home/httpd/html/res/adm/pages/nothumb.gif';
 open (IN,$fn);
 binmode(STDOUT);
 print join('',<IN>); # output image