#!/var/mwt/bin/svc/php
<?php
/**
Logger - general purpose logger, with autorotate capability
Version 0.1
Copyright (C) 2003 Greg MacLellan
Aug 12/2003

greg at mtechsolutions dot ca

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	http://www.gnu.org/copyleft/gpl.html


This program takes input from STDIN, and writes it to a specified file.

For example:

logger 4 /var/log/mylogfile


Will log STDIN to /var/log/mylogfile. Every day, it will archive yesterday's
log to /var/log/mylogfile.1, and the day before to /var/log/mylogfile.2, etc,
up to the number specified. The oldest files will get deleted.

Note that it's ok if there is a log file missing, however, if you have a .8,
and only have 7 specified on the command line (ie, you change the number of
days), it will not touch the .8 file anymore.

Sending the process HUP will make it re-open the log file, and sending TERM
will do a graceful shutdown.

Real use:

./somedaemon | logger 7 /var/log/somedaemon



I wrote this program as a quick hack to make syslog-style logs that rotate
themselves with no external crontab or configuration needed. Feel free to
improve and/or make changes, as it's licened under the GPL. If you find bugs,
either fix them and send me a patch, or
let me know and I'll see if I can fix it.


- Greg

*/


declare(ticks=1);

define("DATE_FORMAT", "M d H:i:s");
define("DEBUG", 0);

/*** Function definitions ***/

function signal_handler($signo) {
	global $lh, $logfile;

	switch ($signo) {
		case SIGHUP:
			//reopen file
			fwrite(STDOUT, "caught SIGHUP, reopening log file\n");
			fclose($lh);
			$lh = fopen($logfile, "a");
		break;
		case SIGTERM:
			//shut down
			fwrite(STDOUT, "caught SIGTERM, shutting down\n");
			fclose($lh);
			exit(0);
		break;
	}
}

/** returns a "day stamp" .. number of days since jan 1 1970 gmt
 */
function unixdays($date) {
	// (date + timezone-offset) / seconds-in-a-day
	return floor( ($date+date("Z")) / 86400 );
}

function rotate($fileprefix, $days) {
	if (file_exists($fileprefix.".".$days)) {
		// delete oldest
		fwrite(STDOUT, "deleting ".$fileprefix.".".$days."\n");
		unlink($fileprefix.".".$days);
	}

	for ($i = $days-1; $i >= 0; $i--) {
		debug($i);
		//(if $i = 0, then it means just $fileprefix)
		$old = $fileprefix.(($i>0) ? ".".$i : "");
		$new = $fileprefix.".".($i+1);

		if (file_exists($old)) {
			// rename it
			fwrite(STDOUT, "renaming ".$old." to ".$new."\n");
			rename($old, $new);
		}
	}
}

function debug($text) {
	if (DEBUG != 0) {
		fwrite(STDOUT, "::DEBUG:: ".$text."\n");
	}
}

/*** Main code ***/

pcntl_signal(SIGTERM, "signal_handler"); // set signal handlers
pcntl_signal(SIGHUP, "signal_handler");

// parse days commmand-line arg
if (!isset($_SERVER["argv"][1]) || !is_numeric($_SERVER["argv"][1])) {
	showHelp();
	exit(255);
}
$days = $_SERVER["argv"][1];

// parse filename command-line arg
if (!isset($_SERVER["argv"][2])) {
	showHelp();
	exit(255);
}
$logfile = $_SERVER["argv"][2];

if (file_exists($logfile)) {
	debug("filetime ".date("r", filemtime($logfile)));
	debug("unixdays ".unixdays(filemtime($logfile)));
	debug("unixdays now ".unixdays(time()) );
	if (unixdays(filemtime($logfile)) != unixdays(time())) {
		// rotate files before we start to write
		debug("rotating files");
		rotate($logfile, $days);
	}
}

$lastwrite = time();

// open the log file
$lh = fopen($logfile, "a");
while ($data = fgets(STDIN,1024)) {
	if (strlen($data) > 1) {
		$time = time();

		// check if we need to rotate files
		if (unixdays($lastwrite) != unixdays(time())) {
			// rotate
			rotate($logfile, $days);
		}

		$lastwrite = time();
		fwrite($lh, date(DATE_FORMAT,$time)." ".$data);
	}
}
fclose($lh);

?>