Filter array in PHP using keywords?

Question

What could I add to the following code to filter the returned results using keywords in an array?

The code that send the keywords, and made the funciton call is in Javasript.

The code below opens a file, takes a pointer using a request, opens the file finds the pointer, and retrieves all log lines from the pointer to the end of the file. Then it formats it into a JSON object and sends back to Javacript.

function tail(){
    $keywords = json_decode($_REQUEST['keywords']);

    $file = "/path/to/the/log.log";
    $handle = fopen($file, "r");
    clearstatcache();       

    if ($_REQUEST['pointer'] == '') {
        fseek($handle, -1024, SEEK_END);
    } else {
        fseek($handle, $_REQUEST['pointer']);
    }

    while ($buffer = fgets($handle)) { 
        $log .= $buffer . "<br />\n";
    } 



    $output = array("pointer" => ftell($handle), "log" => $log);
    fclose($handle);

    echo json_encode($output);
}

Please tell me how I can filter the retrieved data using the keywords in the keywords array.

Answer 1

You could split the line on every space and check each word against the supplied keywords:

while ($buffer = fgets($handle)) { 
  $words = explode(' ', $buffer);
  foreach ($words as $word) {
    if (in_array($word, $keywords)) {
      $log .= $buffer . "<br />\n";
      break;
    }
  }
}

or check each keyword against the read line:

while ($buffer = fgets($handle)) { 
  foreach ($keywords as $keyword) {
    if (strstr($buffer, $keyword)) {
      $log .= $buffer . "<br />\n";
      break;
    }
  }
}

Answer 2

Change your read loop to this:

while ($buffer = fgets($handle)) { 
    foreach ($keywords as $kw) { // Loop keywords
        if (strpos($buffer, $kw) !== FALSE) { // Search for this keyword
            // If we get here, we found a keyword
            $log .= $buffer . "<br />\n";
            break;
        }
    }
} 

If you want to match in a case-insensitive manner, you could use stripos() instead.