As I caught myself in process of writing PHP "log" function several times I have finally decided to create a simple Logging PHP class. After Logging class initialization, first call of lwrite method will open log file implicitly and write line to the file. Every other lwrite will use already opened file pointer until closing file with lclose. It is always a good idea to close a file when it’s over. This should prevent file from corruption and overhead in closing file is negligible.
Before you read further, I also wrote a post how to Log PHP errors to the separate file, if you are looking for such information.
How to use Logging class:
// Logging class initialization
$log = new Logging();
// set path and name of log file (optional)
$log->lfile('/tmp/mylog.txt');
// write message to the log file
$log->lwrite('Test message1');
$log->lwrite('Test message2');
$log->lwrite('Test message3');
// close log file
$log->lclose();
Output in mylog.txt will look like:
[10/Jun/2012:10:36:19] (test) Test message1
[10/Jun/2012:10:36:19] (test) Test message2
[10/Jun/2012:10:36:19] (test) Test message3
Logging class source code:
/**
* Logging class:
* - contains lfile, lwrite and lclose public methods
* - lfile sets path and name of log file
* - lwrite writes message to the log file (and implicitly opens log file)
* - lclose closes log file
* - first call of lwrite method will open log file implicitly
* - message is written with the following format: [d/M/Y:H:i:s] (script name) message
*/
class Logging {
// declare log file and file pointer as private properties
private $log_file, $fp;
// set log file (path and name)
public function lfile($path) {
$this->log_file = $path;
}
// write message to the log file
public function lwrite($message) {
// if file pointer doesn't exist, then open log file
if (!is_resource($this->fp)) {
$this->lopen();
}
// define script name
$script_name = pathinfo($_SERVER['PHP_SELF'], PATHINFO_FILENAME);
// define current time and suppress E_WARNING if using the system TZ settings
// (don't forget to set the INI setting date.timezone)
$time = @date('[d/M/Y:H:i:s]');
// write current time, script name and message to the log file
fwrite($this->fp, "$time ($script_name) $message" . PHP_EOL);
}
// close log file (it's always a good idea to close a file when you're done with it)
public function lclose() {
fclose($this->fp);
}
// open log file (private method)
private function lopen() {
// in case of Windows set default log file
if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
$log_file_default = 'c:/php/logfile.txt';
}
// set default log file for Linux and other systems
else {
$log_file_default = '/tmp/logfile.txt';
}
// define log file from lfile method or use previously set default
$lfile = $this->log_file ? $this->log_file : $log_file_default;
// open log file for writing only and place file pointer at the end of the file
// (if the file does not exist, try to create it)
$this->fp = fopen($lfile, 'a') or exit("Can't open $lfile!");
}
}
For PHP prior to version 5.2.0 you will have to replace or change line with built-in PHP function pathinfo() because PATHINFO_FILENAME constant was added in PHP 5.2.0
// for PHP 5.2.0+
$script_name = pathinfo($_SERVER['PHP_SELF'], PATHINFO_FILENAME);
// for PHP before version 5.2.0
$script_name = basename($_SERVER['PHP_SELF']);
$script_name = substr($script_name, 0, -4); // php extension and dot are not needed
If you want to send a message to the PHP’s system logger, please see the error_log PHP command.