loncom/xml/run.pm - view

File: [LON-CAPA] / loncom / xml / run.pm
Revision 1.60: download - view: text, annotated - select for diffs
Mon Nov 24 18:55:01 2008 UTC (15 years, 5 months ago) by jms
Branches: MAIN
CVS tags: version_2_9_X, version_2_9_99_0, version_2_9_1, version_2_9_0, version_2_8_99_1, version_2_8_99_0, version_2_10_X, version_2_10_1, version_2_10_0_RC2, version_2_10_0_RC1, version_2_10_0, loncapaMITrelate_1, language_hyphenation_merge, language_hyphenation, bz6209-base, bz6209, bz5969, bz2851, PRINT_INCOMPLETE_base, PRINT_INCOMPLETE, HEAD, GCI_3, GCI_2, BZ5971-printing-apage, BZ5434-fox, BZ4492-merge, BZ4492-feature_horizontal_radioresponse

Added/modified POD comments

1: package Apache::run; 2: # 3: # $Id: run.pm,v 1.60 2008/11/24 18:55:01 jms Exp $ 4: # 5: # Copyright Michigan State University Board of Trustees 6: # 7: # This file is part of the LearningOnline Network with CAPA (LON-CAPA). 8: # 9: # LON-CAPA is free software; you can redistribute it and/or modify 10: # it under the terms of the GNU General Public License as published by 11: # the Free Software Foundation; either version 2 of the License, or 12: # (at your option) any later version. 13: # 14: # LON-CAPA is distributed in the hope that it will be useful, 15: # but WITHOUT ANY WARRANTY; without even the implied warranty of 16: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17: # GNU General Public License for more details. 18: # 19: # You should have received a copy of the GNU General Public License 20: # along with LON-CAPA; if not, write to the Free Software 21: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22: # 23: # /home/httpd/html/adm/gpl.txt 24: # 25: # http://www.lon-capa.org/ 26: # 27: 28: use HTML::Entities; 29: 30: $Apache::run::EVALUATE_STRING=<<'ENDEVALUATE'; 31: my %_LONCAPA_INTERNAL_oldexpressions=(); 32: while (!$_LONCAPA_INTERNAL_oldexpressions{$_}) { 33: $_LONCAPA_INTERNAL_oldexpressions{$_}=1; 34: $_ =~s/ # $1 will be the variable reference or subroutine name 35: ((?:\$|\&) #look for a starting $ or & 36: (?:[\#|\$]* #support $$ or $#$ etc. 37: [A-Za-z][\w]*| # get variable name 38: \{[A-Za-z][\w]*\})) # for ${a} 39: # $2 is 0 or more array dereferences [] 40: # or hash dereferences {} 41: # the ^$ and ^& is because we do this iteratively 42: # $a[$c] becomes $a[3] which then evaluates 43: ([\[\{][^\$\&\]\}]+[\]\}])*? 44: # $3 is the list of arguments 45: ($[^\$\&$]+\))*? 46: # only match the above if there is not { [ ( coming up 47: # Why? (I.e. this fails &a(1)[2] 48: (?=[^\[\{\(]|$)/ 49: my ($__LC__a,$__LC__b,$__LC__c)=($1,$2,$3); 50: my $__LC__prefix; 51: my $__LC__result; 52: while (1) { 53: if ($__LC__a =~ m-^&(theta|pi|rho)$-) { last; } 54: { 55: use strict; 56: no strict "vars"; 57: if (eval(defined(eval($__LC__a.$__LC__b)))) { 58: $__LC__result= $__LC__prefix.eval($__LC__a.$__LC__b.$__LC__c); 59: last; 60: } 61: } 62: $__LC__prefix.=substr($__LC__a,0,1,""); 63: if ($__LC__a!~m-^(\$|&|\#)-) { last; } 64: } 65: if (!defined($__LC__result)) { 66: $__LC__result=$__LC__prefix.$__LC__a.$__LC__b.$__LC__c; 67: } 68: $__LC__result; 69: /sexg; 70: if (scalar(values(%_LONCAPA_INTERNAL_oldexpressions))>10) {last;} 71: } 72: ENDEVALUATE 73: 74: sub evaluate { 75: my ($expression,$safeeval,$decls) = @_; 76: unless (defined($expression)) { return ''; } 77: if ($Apache::lonxml::evaluate < 1) { return $expression; } 78: my $result = ''; 79: $@=''; 80: $Apache::run::timeout=0; 81: local $main::SIG{'ALRM'} = sub { 82: $Apache::run::timeout=1; 83: die("timeout"); 84: }; 85: my $innererror; 86: eval { 87: &Apache::lonxml::start_alarm(); 88: $safeeval->reval('{'.$decls.';$_=<<\'EXPRESSION\';'."\n".$expression. 89: "\n".'EXPRESSION'."\n".$EVALUATE_STRING.'}'); 90: $innererror=$@; 91: &Apache::lonxml::end_alarm(); 92: }; 93: my $error=$@; 94: if ($error eq '' && $innererror eq '' && !$Apache::run::timeout) { 95: $result = $safeeval->reval('return $_;'); 96: chomp $result; 97: } else { 98: if ($Apache::run::timeout) { 99: $error = 'Code ran too long. It ran for more than '. 100: $Apache::lonnet::perlvar{'lonScriptTimeout'}.' seconds'; 101: } 102: &Apache::lonxml::error('substitution on <pre>'. 103: &HTML::Entities::encode($expression,'<>&"'). 104: '</pre> with <pre>'. 105: &HTML::Entities::encode($decls,'<>&"'). 106: '</pre> caused <pre>'. 107: &HTML::Entities::encode($error,'<>&"').' '. 108: &HTML::Entities::encode($innererror,'<>&"'). 109: '</pre>'); 110: } 111: return $result 112: } 113: 114: sub run { 115: my ($code,$safeeval,$hideerrors) = @_; 116: my @result; 117: $@=''; 118: $Apache::run::timeout=0; 119: local $main::SIG{'ALRM'} = sub { 120: $Apache::run::timeout=1; 121: die("timeout"); 122: }; 123: my $innererror; 124: eval { 125: &Apache::lonxml::start_alarm(); 126: @result=$safeeval->reval($code); 127: $innererror=$@; 128: &Apache::lonxml::end_alarm(); 129: }; 130: my $error=$@; 131: if (($Apache::run::timeout || $error ne '' || $innererror ne '') && !$hideerrors) { 132: if ($Apache::run::timeout) { 133: $error = 'Code ran too long. It ran for more than '. 134: $Apache::lonnet::perlvar{'lonScriptTimeout'}.' seconds'; 135: } 136: my $errormsg='<pre>'.&HTML::Entities::encode($error,'<>&"').' '. 137: &HTML::Entities::encode($innererror,'<>&"'). 138: '</pre> occurred while running <pre>'; 139: $code=&HTML::Entities::encode($code,'<>&"'); 140: if ($innererror=~/line (\d+)/) { 141: my $linenumber=$1; 142: my @code=split("\n",$code); 143: if ($linenumber < scalar(@code)) { 144: $code[$linenumber-1]=''. 145: $code[$linenumber-1].''; 146: } 147: $code=join("\n",@code); 148: } 149: &Apache::lonxml::error($errormsg.$code.'</pre>'); 150: } 151: if ( $#result < '1') { 152: return $result[0]; 153: } else { 154: &Apache::lonxml::debug("Got lots results:$#result:"); 155: return (@result); 156: } 157: } 158: 159: sub dump { 160: my ($target,$safeeval)=@_; 161: my $dump=''; 162: foreach my $symname (sort keys %{$safeeval->varglob('main::')}) { 163: if (($symname!~ /^(INC|SIG)/) && ($symname!~/\027/) && 164: ($symname!~/^\_/) && ($symname!~/\:$/)) { 165: my $line; 166: if ($safeeval->reval('defined($'.$symname.')')) { 167: if ($symname =~ /^\w/) { 168: $line.='$'.$symname.'='.$safeeval->reval('$'.$symname)."\n"; 169: } 170: } 171: if ($safeeval->reval('defined(@'.$symname.')')) { 172: $line.='@'.$symname.'=('. 173: $safeeval->reval('join(",",@'.$symname.')').")"."\n"; 174: } 175: if ($safeeval->reval('defined(%'.$symname.')')) { 176: $line.='%'.$symname.'=('; 177: $line.=$safeeval->reval('join(",",map { $_."=>".$'. 178: $symname.'{$_} } sort keys %'. 179: $symname.')').")"."\n"; 180: } 181: if ($line ne '') { 182: $line=&HTML::Entities::encode($line,'<>&"'); 183: $line=~s|\n| |g; 184: $dump.=$line; 185: } 186: } 187: } 188: $dump.=''; 189: return $dump; 190: } 191: 192: 1; 193: __END__; 194: 195: =pod 196: 197: =head1 NAME 198: 199: Apache::run.pm 200: 201: =head1 SYNOPSIS 202: 203: Used to prevent poorly written problems from 204: causing lingering after effects 205: 206: This is part of the LearningOnline Network with CAPA project 207: described at http://www.lon-capa.org. 208: 209: 210: =head1 NOTABLE SUBROUTINES 211: 212: =over 213: 214: =item run(), dump(), evaluate() 215: 216: =back 217: 218: =cut 219: