Detailed explanation of the use of php fileatime() function and filectime() function

fileatime() function returns the last access time of the specified file.

This function returns the time when the file was last accessed. Returns false if an error occurs. The time is returned as a Unix timestamp.

Syntax

fileatime(filename)

filename Required. Specifies the documents to be checked.

PS: Note: The atime of the file should be changed whenever a data block in the file is read. Performance is affected when an application regularly accesses a large number of files or directories. Some Unix file systems can turn off atime updates when loading to improve the performance of such programs. The USENET newsgroup spool is a common example. In this file system, this function is useless.

The results of this function will be cached. Please use clearstatcache() to clear the cache.

Example

<?php
echo fileatime("test.txt");
echo "Last access: ".date("F d Y H:i:s.",fileatime("test.txt"));
?>

filectime() function returns the last inode modification time of the specified file.

This function returns the last time the inode of the file was modified. Returns false if an error occurs. The time is returned as a Unix timestamp.

Syntax

fileatime(filename)

filename Required. Specifies the documents to be checked.

Tips: The results of this function will be cached. Please use clearstatcache() to clear the cache.

Note: In most Unix file systems, a file is considered modified when its inode data is changed. That is, when the file's permissions, owner, all groups, or other metadata in the inode are updated. See filemtime() (this is the function you want to use to create a "last updated time" footer in a web page) and fileatime().

Note: Some Unix instructions describe ctime as the time when the file was created, which is wrong. In most Unix file systems, there is no creation time for Unix files.

Example

<?php
echo filectime("test.txt");
echo "Last change: ".date("F d Y H:i:s.",filectime("test.txt"));
?>

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