PHP script shell problem

Hello, while trying to run my php script i get this error:
sh: ?: No such file or directory
although i can see in var_dump that the path is correct and does exists.
If you have the answer please help
Thanks!
code below:

PHP:

 public function readFiles(){
            /*--------Declaring--------*/
            $con = new database();
            /*---------Database handling-------*/
            $selectArgs = "SELECT * FROM search_words";
            $runQuery = $con->con()->query($selectArgs);
            while($getQuery = $runQuery->fetch_assoc()):
                $words[] = $getQuery;
            endwhile;

            $dir = '/var/www/clients';
            $sites = scandir($dir);
            $i = 0;
            foreach($sites as $siteToBeScanned):
                $scanDir = scandir("/var/www/clients/$siteToBeScanned/");
                foreach($scanDir as $clients):
                    if($siteToBeScanned == ".." || $siteToBeScanned == "." || $clients == "." || $clients == ".."):
                        continue;
                    else:
                            foreach($words as $result):
                                chdir("/var/www/clients/$siteToBeScanned/$clients/web");
                                shell_exec("grep -l -r ".$result['search_word']);

                               //$virusQuery = "INSERT INTO virus_found (site,page) VALUES ('$siteToBeScanned','$dirToScan')";
                               //$con->con()->query($virusQuery);
                            endforeach;
                        endif;
                endforeach;
            endforeach;
        }

    }

 

not really sure where the error occurs in this part of the script. Could you elaborate more?

 

Maybe $result['search_word'] contains whitspaces? Better use exec to get the output and the return-code

 

.

 

try this

PHP:

chdir("/var/www/clients/$siteToBeScanned/$clients/web");
foreach($words as $result):
  shell_exec("grep -i -l -r \"$result[search_word]\" .");
  //$virusQuery = "INSERT INTO virus_found (site,page) VALUES ('$siteToBeScanned','$dirToScan')";
  //$con->con()->query($virusQuery);
endforeach;