--- loncom/xml/run.pm	2001/10/05 22:27:41	1.19
+++ loncom/xml/run.pm	2003/03/25 03:00:31	1.33
@@ -1,69 +1,104 @@
 package Apache::run;
+#
+# $Id: run.pm,v 1.33 2003/03/25 03:00:31 albertel Exp $
+#
+# Copyright Michigan State University Board of Trustees
+#
+# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
+#
+# LON-CAPA is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# LON-CAPA is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with LON-CAPA; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# /home/httpd/html/adm/gpl.txt
+#
+# http://www.lon-capa.org/
+#
 
-sub evaluateold {
-  my ($expression,$safeeval,$decls) = @_;
-# print "inside2 evaluate $decls with $expression<br />\n";
-# gerd's old method interpolates unset vars
-# $safeeval->reval('return qq('.$expression.');');
-  unless (defined $expression) { return ''; }
-  my $result = '';
-  $@='';
-  $safeeval->reval('$_=q|'.$expression.'|;');
-  if ($@ eq '') {
-    $safeeval->reval('{'.$decls.'$_=~s/(\$[A-Za-z]\w*)/(defined(eval($1))?eval($1):$1)/ge;}');
-    if ($@ eq '') {
-      $result = $safeeval->reval('return $_;');
-    } else {
-      &Apache::lonxml::error("substitution on:$expression:with:$decls:caused");
-    }
-  } else {
-    &Apache::lonxml::error("defining:$expression:caused");
-  }
-  if ($@ ne '') {&Apache::lonxml::error($@);}
-  return $result
-}
+use HTML::Entities;
 
 $Apache::run::EVALUATE_STRING=<<'ENDEVALUATE';  
-  my %oldexpressions=();
-  while (!$oldexpressions{$_}) {
-    $oldexpressions{$_}=1;
+  my %_LONCAPA_INTERNAL_oldexpressions=();
+  while (!$_LONCAPA_INTERNAL_oldexpressions{$_}) {
+    $_LONCAPA_INTERNAL_oldexpressions{$_}=1;
     $_ =~s/((?:\$|\&)(?:[\#|\$]*[A-Za-z][\w]*|\{[A-Za-z][\w]*\}))([\[\{][^\$\&\]\}]+[\]\}])*?(\([^\$\&\)]+\))*?(?=[^\[\{\(]|$)/eval(defined(eval($1.$2))?eval('$1.$2.$3'):'$1.$2.$3')/seg;
+    if (scalar(values(%_LONCAPA_INTERNAL_oldexpressions))>10) {last;}
   }
 ENDEVALUATE
 
 sub evaluate {
-  my ($expression,$safeeval,$decls) = @_;
-  unless (defined $expression) { return ''; }
-  if (!$Apache::lonxml::evaluate) { return $expression; }
-  my $result = '';
-  $@='';
-  $safeeval->reval('{'.$decls.';$_=<<\'EXPRESSION\';'."\n".$expression.
-		   "\n".'EXPRESSION'."\n".$EVALUATE_STRING.'}');
-#  $safeeval->reval('{'.$decls.';<< &evaluate(q|'.$expression.'|);}');
-  if ($@ eq '') {
-    $result = $safeeval->reval('return $_;');
-    chomp $result;
-  } else {
-    &Apache::lonxml::error("substitution on:$expression:with:$decls:caused $@");
-  }  
-  return $result
+    my ($expression,$safeeval,$decls) = @_;
+    unless (defined($expression)) { return ''; }
+    if ($Apache::lonxml::evaluate < 1) { return $expression; }
+    my $result = '';
+    $@='';
+    $Apache::run::timeout=0;
+    $main::SIG{'ALRM'} = sub {
+	$Apache::run::timeout=1;
+	die("timeout");
+    };
+    eval {
+	alarm(Apache->request->server->timeout);
+	$safeeval->reval('{'.$decls.';$_=<<\'EXPRESSION\';'."\n".$expression.
+			 "\n".'EXPRESSION'."\n".$EVALUATE_STRING.'}');
+	alarm(0);
+    };
+    my $error=$@;
+    if ($error eq '' && !$Apache::run::timeout) {
+	$result = $safeeval->reval('return $_;');
+	chomp $result;
+    } else {
+	if ($Apache::run::timeout) {
+	    $error = 'Code ran too long. It ran for more than '.
+		Apache->request->server->timeout.' seconds';
+	}
+	&Apache::lonxml::error('substitution on <pre>'.$expression.
+			       '</pre> with <pre>'.$decls.
+			       '</pre> caused <pre>'.$error);
+    }
+    return $result
 }
 
 sub run {
-  my ($code,$safeeval,$hideerrors) = @_;
-#  print "inside run\n";
-  $@='';
-  my (@result)=$safeeval->reval($code);
-  if ($@ ne '' && !$hideerrors) {
-    &Apache::lonxml::error(":$code:caused");
-    &Apache::lonxml::error($@);
-  }
-  if ( $#result < '1') {
-    return $result[0];
-  } else {
-    &Apache::lonxml::debug("<b>Got lots results</b>:$#result:");
-    return (@result);
-  }
+    my ($code,$safeeval,$hideerrors) = @_;
+    my @result;
+    $@='';
+    $Apache::run::timeout=0;
+    $main::SIG{'ALRM'} = sub {
+	$Apache::run::timeout=1;
+	die("timeout");
+    };
+    eval {
+	alarm(Apache->request->server->timeout);
+	@result=$safeeval->reval($code);
+	alarm(0);
+    };
+    my $error=$@;
+    if (($Apache::run::timeout || $error ne '') && !$hideerrors) {
+	if ($Apache::run::timeout) {
+	    $error = 'Code ran too long. It ran for more than '.
+		Apache->request->server->timeout.' seconds';
+	}
+	&Apache::lonxml::error('<pre>'.&HTML::Entities::encode($error).
+			       '</pre> occured while running <pre>'.
+			       &HTML::Entities::encode($code).'</pre>');
+    }
+    if ( $#result < '1') {
+	return $result[0];
+    } else {
+	&Apache::lonxml::debug("<b>Got lots results</b>:$#result:");
+	return (@result);
+    }
 }
 
 sub dump {
@@ -71,19 +106,21 @@ sub dump {
   my $dump='';
   foreach my $symname (sort keys %{$safeeval->varglob('main::')}) {
     if (($symname!~/^\_/) && ($symname!~/\:$/)) {
-      if ($safeeval->reval('defined $'.$symname)) {
-	$dump.='$'.$symname.'='.$safeeval->reval('$'.$symname)."\n";
+      my $line;
+      if ($safeeval->reval('defined($'.$symname.')')) {
+	$line='$'.$symname.'='.$safeeval->reval('$'.$symname);
       }	
-      if ($safeeval->reval('defined @'.$symname)) {
-	$dump.='@'.$symname.'=('.
-	  $safeeval->reval('join(",",@'.$symname.')').")\n";
+      if ($safeeval->reval('defined(@'.$symname.')')) {
+	$line='@'.$symname.'=('.
+	  $safeeval->reval('join(",",@'.$symname.')').")";
       }
-      if ($safeeval->reval('defined %'.$symname)) {
-	$dump.='%'.$symname.'=(';
-	$dump.=$safeeval->reval('join(",",map { $_."=>".$'.
+      if ($safeeval->reval('defined(%'.$symname.')')) {
+	$line='%'.$symname.'=(';
+	$line.=$safeeval->reval('join(",",map { $_."=>".$'.
 				$symname.'{$_} } sort keys %'.
-				$symname.')').")\n";
+				$symname.')').")"
       }
+      if ($line ne '') { $dump.=&HTML::Entities::encode($line)."<br />\n"; }
     }
   }
   $dump.='';