Using PHP filemtime to Retrieve File Modification Time

PHP's filemtime function returns the last modification timestamp of a file when provided with the file path.

The function can be combined with date to format the timestamp into a human‑readable date and time.

Example – retrieving a single file's modification time:

$file_path = 'path/to/file.txt';
$modification_time = filemtime($file_path);
echo "文件最后修改时间：" . date('Y-m-d H:i:s', $modification_time);

This script defines the file path, calls filemtime to get the timestamp, and uses date to display it.

Example – retrieving modification times for multiple files:

$files = array(
    'path/to/file1.txt',
    'path/to/file2.txt',
    'path/to/file3.txt'
);
foreach ($files as $file_path) {
    $modification_time = filemtime($file_path);
    echo "文件：'" . basename($file_path) . "' 最后修改时间：" . date('Y-m-d H:i:s', $modification_time) . "<br>";
}

The loop iterates over an array of file paths, obtains each file's timestamp with filemtime, and prints the filename and formatted modification time.

In summary, by passing a file path to filemtime and optionally formatting the result with date, developers can easily access and display file modification times in PHP.