--- loncom/xml/run.pm	2000/06/29 18:53:24	1.4
+++ loncom/xml/run.pm	2003/11/09 01:17:35	1.42
@@ -1,19 +1,148 @@
 package Apache::run;
+#
+# $Id: run.pm,v 1.42 2003/11/09 01:17:35 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/
+#
+
+use HTML::Entities;
+
+$Apache::run::EVALUATE_STRING=<<'ENDEVALUATE';  
+  my %_LONCAPA_INTERNAL_oldexpressions=();
+  while (!$_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) = @_;
-#  print "inside2 evaluate with $expression\n";
-# gerd's old method interpolates unset vars
-#  $safeeval->reval('return qq('.$expression.');');
-  $safeeval->reval('$_=\''.$expression.'\';');
-  $safeeval->reval('{'.$decls.'$_=~s/(\$\{?[A-Za-z]\w*\}?)/(defined(eval($1))?eval($1):$1)/ge;}');
-  $safeeval->reval('return $_;');
+    my ($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");
+    };
+    my $innererror;
+    eval {
+	alarm($Apache::lonnet::perlvar{'lonScriptTimeout'});
+	$safeeval->reval('{'.$decls.';$_=<<\'EXPRESSION\';'."\n".$expression.
+			 "\n".'EXPRESSION'."\n".$EVALUATE_STRING.'}');
+	$innererror=$@;
+	alarm(0);
+    };
+    my $error=$@;
+    if ($error eq '' && $innererror eq '' && !$Apache::run::timeout) {
+	$result = $safeeval->reval('return $_;');
+	chomp $result;
+    } else {
+	if ($Apache::run::timeout) {
+	    $error = 'Code ran too long. It ran for more than '.
+		Apache->request->server->timeout.' seconds';
+	}
+	&Apache::lonxml::error('substitution on <pre>'.
+			       &HTML::Entities::encode($expression).
+			       '</pre> with <pre>'.
+			       &HTML::Entities::encode($decls).
+			       '</pre> caused <pre>'.
+			       &HTML::Entities::encode($error).' '.
+			       &HTML::Entities::encode($innererror).
+			       '</pre>');
+    }
+    return $result
 }
 
 sub run {
-  my ($code,$safeeval) = @_;
-#  print "inside run\n";
-  $safeeval->reval($code);
+    my ($code,$safeeval,$hideerrors) = @_;
+    my @result;
+    $@='';
+    $Apache::run::timeout=0;
+    $main::SIG{'ALRM'} = sub {
+	$Apache::run::timeout=1;
+	die("timeout");
+    };
+    my $innererror;
+    eval {
+	alarm($Apache::lonnet::perlvar{'lonScriptTimeout'});
+	@result=$safeeval->reval($code);
+	$innererror=$@;
+	alarm(0);
+    };
+    my $error=$@;
+    if (($Apache::run::timeout || $error ne '' || $innererror ne '') && !$hideerrors) {
+	if ($Apache::run::timeout) {
+	    $error = 'Code ran too long. It ran for more than '.
+		Apache->request->server->timeout.' seconds';
+	}
+	my $errormsg='<pre>'.&HTML::Entities::encode($error).' '.
+	    &HTML::Entities::encode($innererror).
+	    '</pre> occured while running <pre>';
+	$code=&HTML::Entities::encode($code);
+	if ($innererror=~/line (\d+)/) {
+	    my $linenumber=$1;
+	    my @code=split("\n",$code);
+	    $code[$linenumber-1]='<b><font color="red">'.
+		$code[$linenumber-1].'</font></b>';
+	    $code=join("\n",@code);
+	}
+	&Apache::lonxml::error($errormsg.$code.'</pre>');
+    }
+    if ( $#result < '1') {
+	return $result[0];
+    } else {
+	&Apache::lonxml::debug("<b>Got lots results</b>:$#result:");
+	return (@result);
+    }
+}
+
+sub dump {
+    my ($target,$safeeval)=@_;
+    my $dump='';
+    foreach my $symname (sort keys %{$safeeval->varglob('main::')}) {
+	if (($symname!~/^\_/) && ($symname!~/\:$/)) {
+	    my $line;
+	    if ($safeeval->reval('defined($'.$symname.')')) {
+		$line='$'.$symname.'='.$safeeval->reval('$'.$symname);
+	    }	
+	    if ($safeeval->reval('defined(@'.$symname.')')) {
+		$line='@'.$symname.'=('.
+		    $safeeval->reval('join(",",@'.$symname.')').")";
+	    }
+	    if ($safeeval->reval('defined(%'.$symname.')')) {
+		$line='%'.$symname.'=(';
+		$line.=$safeeval->reval('join(",",map { $_."=>".$'.
+					$symname.'{$_} } sort keys %'.
+					$symname.')').")"
+				    }
+	    if ($line ne '') {$dump.=&HTML::Entities::encode($line)."<br />";}
+	}
+    }
+    $dump.='';
+    return $dump;
 }
 
 1;