<?php
   
   //Log Levels.  The higher the number, the less severe the message
   //Gaps are left in the numbering to allow for other levels
   //to be added later
   define('LOGGER_DEBUG', 100);
   define('LOGGER_INFO', 75);
   define('LOGGER_NOTICE', 50);
   define('LOGGER_WARNING', 25);
   define('LOGGER_ERROR', 10);
   define('LOGGER_CRITICAL', 5);
   
   class Logger {
   
     private $hLogFile;\; private$logLevel;
   
     //Note: private constructor.  Class uses the singleton pattern
     private function __construct() {
       global $cfg;$//system configuration info array from some external file
       
       this->logLevel = $cfg[\text{'}LOGGER\_LEVEL\text{'}];$logFilePath = $cfg[\text{'}LOGGER\_FILE\text{'}];\; if(!\; strlen($logFilePath)) {
         throw new Exception('No log file path was specified ' . 
                             'in the system configuration.');
       }
       
       //Open a handle to the log file.  Suppress PHP error messages.
       //We'll deal with those ourselves by throwing an exception.
       $this->hLogFile\; =\; @fopen($logFilePath, 'a+');
       if(! is_resource($this->hLogFile))\; \{\; throw\; new\; Exception("The\; specified\; log\; file$logFilePath " . 
                             'could not be opened or created for ' . 
                             'writing.  Check file permissions.');
       }
       
     }
   
     public function __destruct() {
       if(is_resource($this->hLogFile))\; \{\; fclose($this->hLogFile);
       }
     }
     
     public static function getInstance() {
       static $objLog;\; if(!isset($objLog)) {
         $objLog\; =\; new\; Logger();\; \}\; return$objLog;
     }
     
     public function logMessage($msg,$logLevel = LOGGER_INFO, $module\; =\; null)\; \{\; if($logLevel <= $this->logLevel)\; \{$time = strftime('\%x \%X', time());
         $msg\; =\; str\_replace("\backslash t",\; \text{'}\; \text{'},$msg);
         $msg\; =\; str\_replace("\backslash n",\; \text{'}\; \text{'},$msg);
       
         $strLogLevel\; =$this->levelToString($logLevel);\; if(isset($module)) {
           $module\; =\; str\_replace("\backslash t",\; \text{'}\; \text{'},$module);
           $module\; =\; str\_replace("\backslash n",\; \text{'}\; \text{'},$module);
         }  
        
         //logs: date/time loglevel message modulename
         //separated by tabs, new line delimited       
         $logLine\; =\; "$time\t$strLogLevel\backslash t$msg\t$module\backslash n";\; fwrite($this->hLogFile, $logLine);\; \}\; \}\; public\; static\; function\; levelToString($logLevel) {
       switch ($logLevel)\; \{\; case\; LOGGER\_DEBUG:\; return\; \text{'}LOGGER\_DEBUG\text{'};\; break;\; case\; LOGGER\_INFO:\; return\; \text{'}LOGGER\_INFO\text{'};\; break;\; case\; LOGGER\_NOTICE:\; return\; \text{'}LOGGER\_NOTICE\text{'};\; break;\; case\; LOGGER\_WARNING:\; return\; \text{'}LOGGER\_WARNING\text{'};\; break;\; case\; LOGGER\_ERROR:\; return\; \text{'}LOGGER\_ERROR\text{'};\; break;\; case\; LOGGER\_CRITICAL:\; return\; \text{'}LOGGER\_CRITICAL\text{'};\; default:\; return\; \text{'}[unknown]\text{'};\; \}\; \}\; \}\; ?>$