How to solve the problem that the file creation time (filectime) does not change after PHP deletes the file and rebuilds it? ?

1. php creates a file named test.html and uses filectime to get the creation time t1

2. php deletes the file named test.html

3. php recreates the file named test.html and uses filectime to get the creation time t2

Why t1 = t2? ? Why is the creation time not updated? ? I used the clearstatcache function to clear the file status cache, but it didn't work. How to solve this problem? ? (Because when judging whether to regenerate the cache file, you need to know the creation time of the cache file, so it is very important..., please solve it~)
The following is the code for the problem that occurs in this situation (it is a bit dense, please be patient and read it) ):

<code>     // 页面缓存
     if ((defined('DEBUG_MODE') && !DEBUG_MODE) && (defined('CACHE_CONTROL') && CACHE_CONTROL)) {
         $opr = $GLOBALS['module'] . '/' . $GLOBALS['platform'] . '/' . $GLOBALS['controller'] . '/' . $GLOBALS['act'];
         $cache_name = md5($opr) . TEMPLATE_SUFFIX;
         $cache_file = APP_DIR . '/' . $GLOBALS['module'] . '/' . $GLOBALS['platform'] . '/Cache/' . $cache_name;
         // 清除文件状态缓存（就我使用的情况来看，压根没毛用...，这什么情况？？）
         clearstatcache();
         // 缓存文件不存在 创建
         if (!$GLOBALS['FOpr']->checkFile($cache_file)) {
            require_once $view_file;
            $GLOBALS['FOpr']->cFile($cache_file);
            $GLOBALS['FOpr']->wData($cache_file , ob_get_contents());
         } else {
            // 超时重新缓存
            if (time() > filectime($cache_file) + CACHE_LIFE_TIME) {
                require_once $view_file;
                // 缓存文件超时时，先删除原缓存文件
                $GLOBALS['FOpr']->dFile($cache_file);
                // 新建同名缓存文件
                //（新建文件时，filectime 获取文件创建时间一直没更新！这个怎么破？？
                // 这导致我没法重新生成缓存文件了！）
                $GLOBALS['FOpr']->cFile($cache_file); 
                // 写入缓存
                $GLOBALS['FOpr']->wData($cache_file , ob_get_contents() , 'w');
            } else {
                // 加载缓存文件
                require_once $cache_file;
            }
         }
     } else {
         // 显示动态文件（非缓存）
         require_once $view_file;
     }</code>

Reply content:

1. php creates a file named test.html and uses filectime to get the creation time t1

2. php deletes the file named test.html

3. php recreates the file named test.html and uses filectime to get the creation time t2

Why t1 = t2? ? Why is the creation time not updated? ? I used the clearstatcache function to clear the file status cache, but it didn't work. How to solve this problem? ? (Because when judging whether to regenerate the cache file, you need to know the creation time of the cache file, so it is very important..., please solve it~)
The following is the code for the problem that occurs in this situation (it is a bit dense, please be patient and read it) ):

<code>     // 页面缓存
     if ((defined('DEBUG_MODE') && !DEBUG_MODE) && (defined('CACHE_CONTROL') && CACHE_CONTROL)) {
         $opr = $GLOBALS['module'] . '/' . $GLOBALS['platform'] . '/' . $GLOBALS['controller'] . '/' . $GLOBALS['act'];
         $cache_name = md5($opr) . TEMPLATE_SUFFIX;
         $cache_file = APP_DIR . '/' . $GLOBALS['module'] . '/' . $GLOBALS['platform'] . '/Cache/' . $cache_name;
         // 清除文件状态缓存（就我使用的情况来看，压根没毛用...，这什么情况？？）
         clearstatcache();
         // 缓存文件不存在 创建
         if (!$GLOBALS['FOpr']->checkFile($cache_file)) {
            require_once $view_file;
            $GLOBALS['FOpr']->cFile($cache_file);
            $GLOBALS['FOpr']->wData($cache_file , ob_get_contents());
         } else {
            // 超时重新缓存
            if (time() > filectime($cache_file) + CACHE_LIFE_TIME) {
                require_once $view_file;
                // 缓存文件超时时，先删除原缓存文件
                $GLOBALS['FOpr']->dFile($cache_file);
                // 新建同名缓存文件
                //（新建文件时，filectime 获取文件创建时间一直没更新！这个怎么破？？
                // 这导致我没法重新生成缓存文件了！）
                $GLOBALS['FOpr']->cFile($cache_file); 
                // 写入缓存
                $GLOBALS['FOpr']->wData($cache_file , ob_get_contents() , 'w');
            } else {
                // 加载缓存文件
                require_once $cache_file;
            }
         }
     } else {
         // 显示动态文件（非缓存）
         require_once $view_file;
     }</code>

As far as your application scenario is concerned:

• filemtime can better complete the Cache timeout judgment logic;

• The file does not need to be deleted, because the filemtime will change after rewriting;

• There must be a reason why you deleted the file, but please see the "off-topic" under the answer

As far as deleting and creating files in PHP

The author did an experiment using the following code

<code>$path = __DIR__.'/test.txt';

file_put_contents($path, 'content1');
echo filectime($path),PHP_EOL;

unlink($path);
sleep(2);

file_put_contents($path, 'content2');
echo filectime($path),PHP_EOL;</code>

Result:

windows (windows 10 x64)

The return time is indeed the same. When I execute it for the second time, the time is still the same as the first time.
But I did see this txt disappear for 2 seconds and then be generated again. This may have such a logic under Windows (I haven’t gone into it yet). The picture below shows the file attributes I got after executing it for the second time:

CentOS under Linux

The return time will change

Off topic

In some file cache engines I wrote or I saw, the read cache operation did not delete the Cache file even if a timeout was detected.

• I’m not being lazy here, after all it’s easy to unlink

• Instead, it reduces necessary i/o requests and the risk of unlink caused by concurrency (Think about why?)

• Besides, according to inertial thinking, since you are accessing this cache, this cache will definitely be overwritten, so there is not much meaning in rebuilding after deletion

• The only problem is disk space occupation. For example, some caches that have not been accessed for a long time still occupy space. For this situation, we generally choose to tolerate it, or implement the code ourselves and use scheduled tasks to delete it

• smarty compiled files are similar to your scenario, his approach is: don’t delete