Detailed explanation of the use of php clearstatcache() function

clearstatcache() function clears the file status cache.

PHP will cache the return information of some functions to provide higher performance. But sometimes, such as when you check the same file multiple times in a script and the file is in danger of being deleted or modified during the execution of the script, you need to clear the file status cache in order to get the correct results. To do this, use the clearstatcache() function.

Syntax

clearstatcache()

Tips: Functions that perform caching, that is, functions affected by the clearstatcache() function:

• stat()

• lstat()

• file_exists()
  

• is_writable( )
  

• is_readable()
  

• ##is_executable()

  
  

• is_file()

  
  

• is_dir()

  
  

• is_link()

  
  

• filectime()
  

• ##fileatime

  ()
  

• filemtime

  ()
  

fileinode()

• 
  

filegroup()

• 
  

##fileowner
• ()

  
  

  filesize()

• 
  ##filetype()

• 
  

  fileperms
( )

• 
  

  ##clearstatcache() function example code is as follows:

<?php 
//check filesize 
echo filesize("test.txt"); 
echo "<br />"; 
$file = fopen("test.txt", "a+"); 
// truncate file 
ftruncate($file,100); 
fclose($file);//Clear cache and check filesize againcle 
arstatcache(); 
echo filesize("test.txt"); 
?>

The above code will output the following results:

792100

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