--- loncom/xml/run.pm	2000/10/02 22:20:18	1.7
+++ loncom/xml/run.pm	2004/02/26 23:39:04	1.45
@@ -1,38 +1,163 @@
 package Apache::run;
+#
+# $Id: run.pm,v 1.45 2004/02/26 23:39:04 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/  # $1 will be the variable reference or subroutine name
+            ((?:\$|\&) #look for a starting $ or &
+             (?:[\#|\$]* #support $$ or $#$ etc.
+              [A-Za-z][\w]*| # get variable name
+              \{[A-Za-z][\w]*\})) # for ${a}
+             # $2 is 0 or more array dereferences []
+             #             or  hash dereferences {}
+             # the ^$ and ^& is because we do this iteratively
+             #    $a[$c] becomes $a[3] which then evaluates
+             ([\[\{][^\$\&\]\}]+[\]\}])*?
+             # $3 is the list of arguments
+             (\([^\$\&\)]+\))*?
+                # only match the above if there is not { [ ( coming up
+                # Why? (I.e. this fails &a(1)[2]
+                (?=[^\[\{\(]|$)/
+         &__LC_INTERNAL_EVALUATE__($1,$2,$3)/sexg;
+    if (scalar(values(%_LONCAPA_INTERNAL_oldexpressions))>10) {last;}
+}
+ENDEVALUATE
 
 sub evaluate {
-  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 = '';
-  $@='';
-  $safeeval->reval('$_=\''.$expression.'\';');
-  if ($@ eq '') {
-    $safeeval->reval('{'.$decls.'$_=~s/(\$\{?[A-Za-z]\w*\}?)/(defined(eval($1))?eval($1):$1)/ge;}');
-    if ($@ eq '') {
-      $result = $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 $result;
     } else {
-      &Apache::lonxml::error("substituion on:$expression:with:$decls:caused");
+	if ($Apache::run::timeout) {
+	    $error = 'Code ran too long. It ran for more than '.
+		$Apache::lonnet::perlvar{'lonScriptTimeout'}.' seconds';
+	}
+	&Apache::lonxml::error('substitution on <pre>'.
+			       &HTML::Entities::encode($expression).
+			       '</pre> with <pre>'.
+			       &HTML::Entities::encode($decls).
+			       '</pre> caused <pre>'.
+			       &HTML::Entities::encode($error).' '.
+			       &HTML::Entities::encode($innererror).
+			       '</pre>');
     }
-  } else {
-    &Apache::lonxml::error("defining:$expression:caused");
-  }
-  if ($@ ne '') {&Apache::lonxml::error($@);}
-  return $result
+    return $result
 }
 
 sub run {
-  my ($code,$safeeval) = @_;
-#  print "inside run\n";
-  $@='';
-  my $result=$safeeval->reval($code);
-  if ($@ ne '') { 
-    &Apache::lonxml::error(":$code:caused"); 
-    &Apache::lonxml::error($@); 
-  }
-  return $result;
+    my ($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::lonnet::perlvar{'lonScriptTimeout'}.' 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;