parser.php

<?php

/**
 *
 * Simple Log Parser
 *
 * Calculates number of NOK records per minute
 *
 * Log file should have records in the following format:
 *
 *
 * [2018-04-11   03:13:57]  OK
 *
 * [2018-04-11   03:14:04]  OK
 *
 * [2018-04-11 03:14:04] NOK
 *
 * [2018-04-11 03:14:09] OK
 *
 * [2018-04-11 03:14:15] NOK
 *
 * [2018-04-11 03:15:10] NOK
 *
 * [2018-04-11    03:15:15] NOK
 *
 * [2018-04-11 03:16:15] NOK
 */

class LogParser {

	var $begin_time = null;

	var $end_time = null;

	var $verbose = false;

	var $log_filename = null;

	var $logfile_content = null;

	var $nok_rows_per_minute = 0;

	var $total_nok_rows = 0;

	function __construct() {
	}

	static function main() {
		$parser = new LogParser();
		$parser->parse_command_line();

		$parser->start();
		try {
			$parser->run();
		} catch ( Exception $e ) {
			$parser->log( LOG_CRIT, get_class( $e ) . ": " . $e->getMessage() );

			return;
		} finally {
			$parser->finish();
		}
	}

	static function _level_for_priority( $priority ) {
		if ( $priority == LOG_DEBUG ) {
			$level = "DEBUG";
		} elseif ( $priority == LOG_INFO ) {
			$level = "INFO";
		} elseif ( $priority == LOG_NOTICE ) {
			$level = "NOTICE";
		} elseif ( $priority == LOG_WARNING ) {
			$level = "WARNING";
		} elseif ( $priority == LOG_ERR ) {
			$level = "ERR";
		} elseif ( $priority == LOG_CRIT ) {
			$level = "CRIT";
		} elseif ( $priority == LOG_ALERT ) {
			$level = "ALERT";
		} elseif ( $priority == LOG_EMERG ) {
			$level = "EMERG";
		} else {
			$level = $priority;
		}

		return $level;
	}


	function usage( $extra_options = "", $extra_options_verbose = "" ) {
		global $argv;

		print "Usage: " . $argv[0] . " [-h] [-v] " . $extra_options . "\n";
		print "  -h               Help message (this)\n";
		print "  -v               Verbose error logging (to stderr)\n";
		print "  -f <filename>    events log file\n";
		print $extra_options_verbose;
	}

	function parse_command_line( $extra_options = "" ) {
		$opts = getopt( "hvf:" . $extra_options );
		if ( isset( $opts['h'] ) || ! isset( $opts['f'] ) || empty( $opts['f'] ) ) {
			$this->usage( $extra_options );
			exit();
		}

		if ( isset( $opts['v'] ) ) {
			$this->set_verbose();
		}

		if ( isset( $opts['f'] ) ) {
			$this->set_log_filename( $opts['f'] );
		}

		return $opts;
	}

	function set_verbose( $setting = true ) {
		$this->verbose = $setting;
	}

	function set_log_filename( $filename ) {
		$this->log_filename = $filename;
		$this->log( LOG_NOTICE, "File {$filename} being processed to calculate number of NOK records per minute" );
	}

	function start() {
		$this->begin_time = microtime( true );
	}

	function run() {

		$this->load_log_file();

		$this->log( LOG_NOTICE, "processing {$this->log_filename} to calculate number of NOK records per minute" );

		preg_match_all( '/(\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}):\d{2}.*?NOK$/im', $this->logfile_content, $nok_rows );

		$this->total_nok_rows = count( $nok_rows[0] );

		$this->nok_rows_per_minute = array_count_values( array_map( fn( $row ): string => preg_replace( '/\s+/', ' ', $row ), $nok_rows[1] ) );

		$this->report();
	}

	function load_log_file() {
		if ( is_null( $this->log_filename )
		     || empty( $this->log_filename ) ) {
			throw new Exception( "no filename specified" );
		}

		if ( ! is_file( $this->log_filename ) ) {
			throw new Exception( "File {$this->log_filename} not found!" );
		}

		// considering the logfile is pretty small, we load it to memory completely  
		$this->logfile_content = file_get_contents( $this->log_filename );

		$this->log( LOG_NOTICE, "{$this->log_filename} has been loaded" );
	}

	function finish() {
		$this->end_time = microtime( true );

		$this->log( LOG_NOTICE, "Script executed for " . ( $this->end_time - $this->begin_time ) . " seconds" );
	}

	function report() {

		print "\nNOK rows per minute:\n";
		foreach ( $this->nok_rows_per_minute as $timestamp => $nok_count ) {
			print "{$timestamp} ${nok_count}\n";
		}

		print "------------------\n";
		print "Total NOK rows in file: {$this->total_nok_rows}\n\n";
	}

	function log( $priority, $message ) {
		$level = self::_level_for_priority( $priority );

		if ( $this->verbose && $priority <= LOG_INFO || $priority <= LOG_CRIT ) {
			fwrite( STDERR, ( $this->verbose ? date( "Y-m-d H:i:s" ) . " ({$level}) : " : "" ) . "{$message}\n" );
		}
	}
}


if ( isset( $argv ) && basename( __FILE__ ) == basename( $argv[0] ) ) {
	LogParser::main();
}