Re: Evaluating php code.

I'd leave the code checker in the global scope. In testing here I am not getting a fatal error on a call to a method on a non-existing object. This code returns nothing: <? $code = ' <? $a = 1; $b->foo(); ?> '; error_reporting(0); ini_set('track_errors',true); $php_errrormsg=''; ob_start(); eval('?>'.$code); $output = ob_get_contents(); ob_end_clean(); if($php_errormsg) echo "Error was: $php_errormsg<br>\n"; else echo "Output was: $output<br>\n"; ?> Does this give you a fatal error? If so, you may want to look at updating your PHP. -Rasmus On Wed, 3 Apr 2002, Scott Houseman wrote: > Hi Rasmus. > > Thanks for the help. > I've implemented your code in a method in class 'RendererParam' as follows: > //-------------------------------------------------------------------------- > ----------------------------------- > // evaluateParameter > //-------------------------------------------------------------------------- > ----------------------------------- > /** > Evaluate the parameter's code. > */ > function evaluateParameter ( ) { > // Give variable containing error message global scope. > global $php_errormsg; > echo "Evaluate code...<BR>"; > // Supress error reporting. > error_reporting( 0 ); > // Set 'track_errors' on. > ini_set( 'track_errors', true ); > // Clean out error variable. > $php_errormsg = ""; > // Start output buffering. > echo "eval( $this->sParamName.' = > '.$this->sParamValue.';' )<BR>"; > ob_start( ); > // Evaluate this parameter. > eval( $this->sParamName.' = '.$this->sParamValue.';' ); > // Get the output buffer contents. > $sBufferOutput = ob_get_contents( ); > // End output buffering. > ob_end_clean( ); > echo '$sBufferOutput = '.$sBufferOutput.'<BR>'; > if ( trim( $php_errormsg ) != '' ) { > echo "Error was: $php_errormsg<br>\n"; > return false; > } > else { > echo "Output was: $sBufferOutput<br>\n"; > return true; > } > } > //-------------------------------------------------------------------------- > ----------------------------------- > Example output: > > Evaluate code... > eval( $AUTHOR.' = '.$oArticle->oAuthor->getName( ).';' ) > > This works greate for parse errors, which is all I really want to check for. > But I have picked up a problem. > As the parameters (read variables ) & their values entered by the user may > not be in scope at the time they are entered, > in the above case I would get a fatal error: > > Fatal error: Call to a member function on a non-object > in /var/www/vne/vne_classes/entity/RendererParam.inc(350) : eva()'d > code on line 1 > > This is most obviously because I am trying to call a method of an object > which does not exist > If I understand correctly, 'error_reporting( 0 );' will supress error > messages, but this fatal error will still cause > the php preprocessor to die. > > Doing a 'global $$this->sParamName, $$this->sParamValue;' will not help > either, as these given variables/objects > will not necessarly be available in the scope outside of this method either. > > So... > Is there any way of telling the parser to ignore this fatal error and carry > on, or alernatively, > a way of parsing a string at face value for parse errors ie. 'Look for > syntax errors, but don't evaluate the code.'? > > Thanks again for the help, it is much appreciated > > Regards > > Scott > > ----- Original Message ----- > From: "Rasmus Lerdorf" <rasmus@lerdorf.ca> > To: "Scott Houseman" <ScottH@jamwarehouse.com> > Cc: "php-general" <php-general@lists.php.net> > Sent: Wednesday, April 03, 2002 10:33 AM > Subject: Re: [PHP] Evaluating php code. > > > > > Ideally, i'd like to evaluate the code the user has submitted, and if an > > > error is generated, notify the user of that fact. > > > Eval always returns false, and I'd like no runtime error to be > generated. > > > Perhaps an error-handler is what's needed? > > > > > > What can you suggest? > > > > I think this should illustrate how to do that: > > > > <? > > $code = ' > > > > <? > > $a = 1; > > print $a; > > ?> > > > > '; > > > > error_reporting(0); > > ini_set('track_errors',true); > > $php_errrormsg=''; > > ob_start(); > > eval('?>'.$code); > > $output = ob_get_contents(); > > ob_end_clean(); > > if($php_errormsg) echo "Error was: $php_errormsg<br>\n"; > > else echo "Output was: $output<br>\n"; > > ?> > > > > A couple of tricks: > > > > 1. Turning off PHP's error_reporting makes sure no errors are shown by PHP > > 2. Turning on track_errors puts any errors into the $php_errormsg variable > > 3. Turning on output buffering lets you catch the output from the code you > > are testing > > 4. Preceding the eval()'ed code with ?> makes sure you start the code off > > in normal HTML mode since eval() actually assumes what you feed it > > starts in PHP mode which is likely not the case for you. > > > > -Rasmus > > > > >