php 之静态变量

由于要写个多进程同时访问一个文件的功能函数,结果用到这个,记录笔记

<?php
function write_file($file,$msg,$usecheck=5){
	static $check=1;//这里用到了~
	$f=@fopen($file,"a+b");
	if($f){
		if(flock($f,LOCK_EX)){
			fwrite($f,$msg);
			flock($f,LOCK_UN);
			fclose($f);
		}else{
			fclose($f);
			$check++;
			if($check<=$usecheck){
				sleep(1);//暂停下程序,等其他进程释放该资源
				write_file($file,$msg);
			}
		}
	}else{
		$check++;
		if($check<=$usecheck){
			sleep(1);//暂停下程序,等其他进程释放该资源
			write_file($file,$msg);
		}
	}
}