mailtodisk.php

<?php
/*
	メールをディスクに保存する
	
	Based on rudiedirkx/mailtodisk.php
	https://gist.github.com/rudiedirkx/ae893b4041aadda70d42

	[php.ini]
	sendmail_path = "C:\Server\php72nts\php.exe C:\Server\mailtodisk.php \"C:\Server\var\mailoutput\__TIME__-__RAND__-__SUBJECT__.eml\""
	sendmail_path = "/usr/bin/php /var/www/mailtodisk.php \"/var/www/mailoutput/__TIME__-__RAND__-__SUBJECT__.eml\""
*/

const DateFormat = 'Ymd-His-v';

function putLog($message) {
	file_put_contents(__DIR__ . '/mailtodisk.log', $message . PHP_EOL, LOCK_EX | FILE_APPEND);
}

function filenameFilter($subject) {
	return preg_replace('/_{2,}/', '_', trim(preg_replace('/[^a-z0-9ぁ-ゟァ-ヿ一-龠-]/iu', '_', $subject), '_'));
}

// エラー→例外 ハンドラを登録する
set_error_handler(
	function ($errno, $errstr, $errfile, $errline) {
		// エラーが発生した場合、ErrorExceptionを発生させる
		throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
	},
	(E_ALL | E_STRICT) | (~E_WARNING));

try {
	putLog(date('[Y/m/d H:i:sO]'));
	// putLog(print_r($_SERVER, 1));

	// Destination folder/filename is required
	$destination = @$_SERVER['argv'][1];
	if (!$destination) {
		putLog('ERROR: Missing destination.');
		exit(1);
	}

	// Create target folder
	$dir = dirname($destination);
	if (!file_exists($dir)) {
		mkdir($dir, 0777, true);
	}
	if (!is_dir($dir)) {
		putLog('ERROR: Invalid destination.');
		exit(2);
	}

	// Get entire mail content
	$mail = file_get_contents('php://stdin');
	// putLog($mail);

	// Extract subject
	$subject = 'NO SUBJECT';
	if (preg_match('#Subject:\s+([^\r\n]+)#', $mail, $match)) {
		if (is_callable('imap_utf8')) {
			$subject = imap_utf8($match[1]);
		} else if (is_callable('mb_decode_mimeheader')) {
			$subject = mb_decode_mimeheader($match[1]);
		} else {
			putLog('ERROR: MIME decode function does not exist.');
			exit(3);
		}
	}

	// Create filename with wildcards
	$now = new DateTime();
	$destination = strtr($destination, [
		'__TIME__' => $now->format(DateFormat),
		'__RAND__' => substr(md5(rand()), 0, 8),
		'__SUBJECT__' => filenameFilter($subject),
	]);
	putLog('Destination: ' . $destination);

	file_put_contents($destination, $mail);
	exit(0);

} catch (Exception $e) {
	putLog('ERROR: ' . $e->getMessage());
	putLog($e->getTraceAsString());
}