A minimal PHP logging package based on the idea of using closures for configurability and extensibility. It functions as a static class, but you can completely control the writing of log messages through a closure function (aka anonymous functions), or use the Analog\Logger wrapper that implements the PSR-3 specification.

Install the latest version with:

$ composer require analog/analog

<?php

use Analog\Analog;
use Analog\Handler\FirePHP;

Analog::handler (FirePHP::init ());

Analog::log ('Take me to your browser');

<?php

use Analog\Logger;
use Analog\Handler\Variable;

$logger = new Logger;

$log = '';

$logger->handler (Variable::init ($log));

$logger->alert ('Things are really happening right now!');

// With context
$logger->debug ('Testing {0}:{1}', [__FILE__, __LINE__]);

var_dump ($log);

<?php

use Analog\Analog;

// Default logging to /tmp/analog.txt
Analog::log ('Log this error');

// Log to a MongoDB log collection
Analog::handler (function ($info) {
	static $conn = null;
	if (! $conn) {
		$conn = new Mongo ('localhost:27017');
	}
	$conn->mydb->log->insert ($info);
});

// Log an alert
Analog::log ('The sky is falling!', Analog::ALERT);

// Log some debug info
Analog::log ('Debugging info', Analog::DEBUG);

Analog uses a simple autoloader internally, so if you don't have access to composer you can clone this repository and include it like this:

<?php

require 'analog/lib/Analog.php';

Analog::handler (Analog\Handler\Stderr::init ());

Analog::log ('Output to php://stderr');

For more examples, see the examples folder.

By default, this class will write to a file named sys_get_temp_dir() . '/analog.txt' using the format "machine - date - level - message\n", making it usable with no customization necessary.

Analog also comes with dozens of pre-written handlers in the Analog/Handlers folder, with examples for each in the examples folder. These include:

• Amon - Send logs to the Amon server monitoring tool
• Apprise - Send notifications through the apprise command line tool
• Buffer - Buffer messages to send all at once (works with File, Mail, Stderr, and Variable handlers)
• ChromeLogger - Sends messages to Chrome Logger browser plugin
• EchoConsole - Echo output directly to the console
• File - Append messages to a file
• FirePHP - Send messages to FirePHP browser plugin
• GELF - Send message to the Graylog2 log management server
• IFTTT - Trigger webhooks via the IFTTT service
• Ignore - Do nothing
• LevelBuffer - Buffer messages and send only if sufficient error level reached
• LevelName - Convert log level numbers to names in log output
• Mail - Send email notices
• Mongo - Save to MongoDB collection
• Multi - Send different log levels to different handlers
• PDO - Send messages to any PDO database connection (MySQL, SQLite, PostgreSQL, etc.)
• Post - Send messages over HTTP POST to another machine
• Redis - Save messages to Redis key using RPUSH
• Slackbot - Post messages to Slack via Slackbot
• Stderr - Send messages to STDERR
• Syslog - Send messages to syslog
• Threshold - Only writes log messages above a certain threshold
• Variable - Buffer messages to a variable reference
• WPMail - Send email notices using Wordpress wp_mail()

So while it's a micro class, it's highly extensible and very capable out of the box too.

I wrote this because I wanted something very small and simple like KLogger, and preferably not torn out of a wider framework if possible. After searching, I wasn't happy with the single-purpose libraries I found. With KLogger for example, I didn't want an object instance but rather a static class, and I wanted more flexibility in the back-end.

I also found some that had the flexibility also had more complexity, for example Monolog is dozens of source files (not incl. tests). With closures, this seemed to be a good balance of small without sacrificing flexibility.

What about Analog, the logfile analyzer? Well, since it hasn't been updated since 2004, I think it's safe to call a single-file PHP logging class the same thing without it being considered stepping on toes :)