--- loncom/xml/run.pm 2000/06/29 20:27:44 1.5 +++ loncom/xml/run.pm 2020/03/12 20:20:13 1.66 @@ -1,21 +1,223 @@ package Apache::run; +# +# $Id: run.pm,v 1.66 2020/03/12 20:20:13 raeburn 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; +use Apache::lonlocal; + +$Apache::run::EVALUATE_STRING=<<'ENDEVALUATE'; +my %_LONCAPA_INTERNAL_oldexpressions=(); +while (!$_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] + (?=[^\[\{\(]|$)/ + my ($__LC__a,$__LC__b,$__LC__c)=($1,$2,$3); + my $__LC__prefix; + my $__LC__result; + while (1) { + if ($__LC__a =~ m-^&(theta|pi|rho)$-) { last; } + { + use strict; + no strict "vars"; + if (eval(defined(eval($__LC__a.$__LC__b)))) { + $__LC__result= $__LC__prefix.eval($__LC__a.$__LC__b.$__LC__c); + last; + } + } + $__LC__prefix.=substr($__LC__a,0,1,""); + if ($__LC__a!~m-^(\$|&|\#)-) { last; } + } + if (!defined($__LC__result)) { + $__LC__result=$__LC__prefix.$__LC__a.$__LC__b.$__LC__c; + } + $__LC__result; + /sexg; + if (scalar(values(%_LONCAPA_INTERNAL_oldexpressions))>10) {last;} +} +ENDEVALUATE sub evaluate { - my ($expression,$safeeval,$decls) = @_; -# print "inside2 evaluate with $expression\n"; -# gerd's old method interpolates unset vars -# $safeeval->reval('return qq('.$expression.');'); - unless (defined $expression) { return ''; } - $safeeval->reval('$_=\''.$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; + local $main::SIG{'ALRM'} = sub { + $Apache::run::timeout=1; + die("timeout"); + }; + my $innererror; + eval { + &Apache::lonxml::start_alarm(); + $safeeval->reval('{'.$decls.';$_=<<\'EXPRESSION\';'."\n".$expression. + "\n".'EXPRESSION'."\n".$EVALUATE_STRING.'}'); + $innererror=$@; + &Apache::lonxml::end_alarm(); + }; + my $error=$@; + if ($error eq '' && $innererror eq '' && !$Apache::run::timeout) { + $result = $safeeval->reval('return $_;'); + chomp $result; + } else { + if ($Apache::run::timeout) { + $error = + &mt('Code ran too long. It ran for more than [_1] seconds.', + $Apache::lonnet::perlvar{'lonScriptTimeout'}); + } + &Apache::lonxml::error( + &mt('Substitution on [_1] with [_2] caused:', + '
'. &HTML::Entities::encode($expression,'<>&"').'
', + '
'.&HTML::Entities::encode($decls,'<>&"').'
') + .'
' + .'
'.&HTML::Entities::encode($error,'<>&"').' '
+           .&HTML::Entities::encode($innererror,'<>&"').'
'); + } + return $result; } sub run { - my ($code,$safeeval) = @_; -# print "inside run\n"; - $safeeval->reval($code); + my ($code,$safeeval,$hideerrors) = @_; + my @result; + $@=''; + $Apache::run::timeout=0; + local $main::SIG{'ALRM'} = sub { + $Apache::run::timeout=1; + die("timeout"); + }; + my $innererror; + eval { + &Apache::lonxml::start_alarm(); + @result=$safeeval->reval($code); + $innererror=$@; + &Apache::lonxml::end_alarm(); + }; + my $error=$@; + if (($Apache::run::timeout || $error ne '' || $innererror ne '') && !$hideerrors) { + if ($Apache::run::timeout) { + $error = &mt('Code ran too long. It ran for more than [_1] seconds.', + $Apache::lonnet::perlvar{'lonScriptTimeout'}); + } + $code=&HTML::Entities::encode($code,'<>&"'); + if ($innererror=~/line (\d+)/) { + my $linenumber=$1; + my @code=split("\n",$code); + if ($linenumber < scalar(@code)) { + $code[$linenumber-1]= + ''. + $code[$linenumber-1].''; + } + $code=join("\n",@code); + } + &Apache::lonxml::error( + '
'.&HTML::Entities::encode($error,'<>&"').' '.
+            &HTML::Entities::encode($innererror,'<>&"').
+            '
' + .&mt('This occurred while running: [_1]', + '
'.$code.'
')); + } + if ( $#result < '1') { + return $result[0]; + } else { + &Apache::lonxml::debug("Got lots results:$#result:"); + return (@result); + } +} + +sub dump { + my ($target,$safeeval)=@_; + my $dump=''; + foreach my $symname (sort(keys(%{$safeeval->varglob('main::')}))) { + if (($symname!~ /^(INC|SIG)/) && ($symname!~/\027/) && ($symname!~/\022/) && + ($symname!~/^\_/) && ($symname!~/\:$/) && ($symname ne '!')) { + my $line; + if ($safeeval->reval('defined($'.$symname.')')) { + if ($symname =~ /^\w/) { + $line.='$'.$symname.'='.$safeeval->reval('$'.$symname)."\n"; + } + } + if ($safeeval->reval('@'.$symname)) { + $line.='@'.$symname.'=('. + $safeeval->reval('join(",",@'.$symname.')').")"."\n"; + } + if ($safeeval->reval('%'.$symname)) { + $line.='%'.$symname.'=('; + $line.=$safeeval->reval('join(",",map { $_."=>".$'. + $symname.'{$_} } sort(keys(%'. + $symname.')))').")"."\n"; + } + if ($line ne '') { + $line=&HTML::Entities::encode($line,'<>&"'); + $line=~s|\n|
|g; + $dump.=$line; + } + } + } + $dump.=''; + return $dump; } 1; __END__; + +=pod + +=head1 NAME + +Apache::run.pm + +=head1 SYNOPSIS + +Used to prevent poorly written problems from +causing lingering after effects + +This is part of the LearningOnline Network with CAPA project +described at http://www.lon-capa.org. + + +=head1 NOTABLE SUBROUTINES + +=over + +=item run(), dump(), evaluate() + +=back + +=cut +