| 标题 | PHP中实现crontab代码分享 |
| 范文 | 这篇文章主要介绍了PHP中实现crontab代码分享,本文给出了实现代码和使用方法,需要的朋友可以参考下 1. 准备一个标准crontab文件 ./crontab 代码如下: # m h dom mon dow command * * * * * date > /tmp/cron.date.run 2. crontab -e 将此cron.php脚本加入系统cron 代码如下: * * * * * /usr/bin/php cron.php 3. cron.php 源码 代码如下: // 从./crontab读取cron项，也可以从其他持久存储（mysql、redis）读取 $crontab = file('./crontab'); $now = $_SERVER['REQUEST_TIME']; foreach ( $crontab as $cron ) { $slices = preg_split("/[\s]+/", $cron, 6); if( count($slices) !== 6 ) continue; $cmd = array_pop($slices); $cron_time = implode(' ', $slices); $next_time = Crontab::parse($cron_time, $now); if ( $next_time !== $now ) continue; $pid = pcntl_fork(); if ($pid == -1) { die('could not fork'); } else if ($pid) { // we are the parent pcntl_wait($status, WNOHANG); //Protect against Zombie children } else { // we are the child `$cmd`; exit; } } /* */ class Crontab { /** * Finds next execution time(stamp) parsin crontab syntax, * after given starting timestamp (or current time if ommited) * * @param string $_cron_string: * * 0 1 2 3 4 * * * * * * * - - - - - * | | | | | * | | | | +----- day of week (0 - 6) (Sunday=0) * | | | +------- month (1 - 12) * | | +--------- day of month (1 - 31) * | +----------- hour (0 - 23) * +------------- min (0 - 59) * @param int $_after_timestamp timestamp [default=current timestamp] * @return int unix timestamp - next execution time will be greater * than given timestamp (defaults to the current timestamp) * @throws InvalidArgumentException */ public static function parse($_cron_string,$_after_timestamp=null) { if(!preg_match('/^((\*(\/[0-9]+)?)|[0-9\-\,\/]+)\s+((\*(\/[0-9]+)?)|[0-9\-\,\/]+)\s+((\*(\/[0-9]+)?)|[0-9\-\,\/]+)\s+((\*(\/[0-9]+)?)|[0-9\-\,\/]+)\s+((\*(\/[0-9]+)?)|[0-9\-\,\/]+)$/i',trim($_cron_string))){ throw new InvalidArgumentException("Invalid cron string: ".$_cron_string); } if($_after_timestamp && !is_numeric($_after_timestamp)){ throw new InvalidArgumentException("\$_after_timestamp must be a valid unix timestamp ($_after_timestamp given)"); } $cron = preg_split("/[\s]+/i",trim($_cron_string)); $start = empty($_after_timestamp)?time():$_after_timestamp; $date = array( 'minutes' =>self::_parseCronNumbers($cron[0],0,59), 'hours' =>self::_parseCronNumbers($cron[1],0,23), 'dom' =>self::_parseCronNumbers($cron[2],1,31), 'month' =>self::_parseCronNumbers($cron[3],1,12), 'dow' =>self::_parseCronNumbers($cron[4],0,6), ); // limited to time()+366 - no need to check more than 1year ahead for($i=0;$i<=60*60*24*366;$i+=60){ if( in_array(intval(date('j',$start+$i)),$date['dom']) && in_array(intval(date('n',$start+$i)),$date['month']) && in_array(intval(date('w',$start+$i)),$date['dow']) && in_array(intval(date('G',$start+$i)),$date['hours']) && in_array(intval(date('i',$start+$i)),$date['minutes']) ){ return $start+$i; } } return null; } /** * get a single cron style notation and parse it into numeric value * * @param string $s cron string element * @param int $min minimum possible value * @param int $max maximum possible value * @return int parsed number */ protected static function _parseCronNumbers($s,$min,$max) { $result = array(); $v = explode(',',$s); foreach($v as $vv){ $vvv = explode('/',$vv); $step = empty($vvv[1])?1:$vvv[1]; $vvvv = explode('-',$vvv[0]); $_min = count($vvvv)==2?$vvvv[0]:($vvv[0]=='*'?$min:$vvv[0]); $_max = count($vvvv)==2?$vvvv[1]:($vvv[0]=='*'?$max:$vvv[0]); for($i=$_min;$i<=$_max;$i+=$step){ $result[$i]=intval($i); } } ksort($result); return $result; } } |
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