PHP文件同時訪問

Question

好吧，好吧..所以現在我嚇壞了。

index1.php

<? 
function write_file($filepath,$filecontent) { 
    $openedfile = fopen($filepath,"w+"); //replace with $openedfile = fopen($filepath,"a"); just in case 
    flock($openedfile, LOCK_EX); 
//add here fclose($openedfile); to work 
//add here $openedfile = fopen($filepath,"w+"); to work 
    fwrite($openedfile,$filecontent); 
    flock($openedfile, LOCK_UN); 
    fclose($openedfile); 
} 
function read_file($filepath) { 
    $openedfile = fopen($filepath,"r+"); 
    flock($openedfile, LOCK_SH); 
    sleep(10); 
    $filecontent = file_get_contents($filepath); 
    flock($openedfile, LOCK_UN); 
    fclose($openedfile); 
    return $filecontent; 
} 
write_file("Readme.txt","test 1"); 
$f1 = read_file("Readme.txt"); 
echo $f1; 
?> 

index2.php

<? 
function write_file($filepath,$filecontent) { 
    $openedfile = fopen($filepath,"w+"); //replace with $openedfile = fopen($filepath,"a"); to work 
    flock($openedfile, LOCK_EX); 
//add here fclose($openedfile); to work 
//add here $openedfile = fopen($filepath,"w+"); to work 
    fwrite($openedfile,$filecontent); 
    flock($openedfile, LOCK_UN); 
    fclose($openedfile); 
} 
function read_file($filepath) { 
    $openedfile = fopen($filepath,"r+"); 
    flock($openedfile, LOCK_SH); 
    $filecontent = file_get_contents($filepath); 
    flock($openedfile, LOCK_UN); 
    fclose($openedfile); 
    return $filecontent; 
} 
write_file("Readme.txt","test 2"); 
$f1 = read_file("Readme.txt"); 
echo $f1; 
?> 

我index1.php運行，然後2秒後我運行index2.php。 Index2.php等待index1.php如預期但index1.php示出了10秒後什麼都沒有，而index2.php顯示「測試2」。 發生了什麼事？

編輯：我想通了：d。我的第二個PHP改變

$openedfile = fopen($filepath,"w+"); 

到

$openedfile = fopen($filepath,"a"); 

而且不抹在index2.php執行readme.txt文件了。

Answer 1

這難道不是有做一些與事實的readme.txt文件實際上是空的時間很短的時間，當你打開它寫入文件？我認爲PHP拿出整個文本，而不是用整個文本+添加替換它。當index1.php想要讀取文件時，index2.php可能已經清除了它？順便說一下，你可以在apache日誌中檢查它。

編輯：另外，解鎖文件後立即，index2.php會控制它，覆蓋測試1測試2