custom log function for CodeIgniter

log.php

<?php
class example extends CI_Controller {
	/**
	 * leave log message
	 *
	 * @access private
	 * @param  string $func    (default: __FUNCTION__)
	 * @param  string $level   (default: 'debug')
	 * @param  string $message (default: '')
	 * @return void
	 */
	private function __log() {
		$num_arg = func_num_args();
		$trace = debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS | DEBUG_BACKTRACE_PROVIDE_OBJECT );
		$func = $trace[1]['function'];
		$line = $trace[0]['line'];
		$object = $trace[1]['object'];
		if ( is_object( $object ) )
			$class = get_class( $object );
		else
			$class = get_called_class();

		$level = 'debug';
		$message = '';

		switch ( $num_arg ) {
		case 1:
			$message = func_get_arg( 0 );
			break;
		case 2:
			$message = func_get_arg( 1 );
			$func = method_exists( $this, func_get_arg( 0 ) ) ? func_get_arg( 0 ) : $func;
			$level = ( strcasecmp( $func, func_get_arg( 0 ) ) === 0 ) ? $level : func_get_arg( 0 );
			break;
		default:
			list( $func, $level, $message ) = func_get_args();
			if ( ! method_exists( $class, $func ) ) {
				// maybe swapped
				$temp = $func;
				$func = $level;
				$level = $func;
			}
		}

		$message = str_replace( PHP_EOL, '', $message );
		log_message( $level, "{$class}::{$func}({$line}): {$message}" );
	}
}