filemtime
(PHP 4, PHP 5, PHP 7, PHP 8)
filemtime — ファイルの更新時刻を取得する
説明
この関数は、ファイルのブロックデータが書き込まれた時間を返します。 これは、ファイルの内容が変更された際の時間です。
パラメータ
filename-
ファイルへのパス。
エラー / 例外
失敗したときは E_WARNING が発生します。
例
例1 filemtime() の例
<?php
// 出力例 somefile.txt was last modified: December 29 2002 22:16:23.
$filename = 'somefile.txt';
if (file_exists($filename)) {
echo "$filename was last modified: " . date ("F d Y H:i:s.", filemtime($filename));
}
?>注意
注意:
時刻の精度は、 ファイルシステムによって異なることがあります。
注意: この関数の結果は キャッシュされます。詳細は、clearstatcache() を参照してください。
ヒント
PHP 5.0.0 以降、この関数は、
何らかの URL ラッパーと組合せて使用することができます。
どのラッパーが stat() ファミリーをサポートしているかを調べるには
サポートするプロトコル/ラッパー を参照してください。
参考
- filectime() - ファイルの inode 変更時刻を取得する
- stat() - ファイルに関する情報を取得する
- touch() - ファイルの最終アクセス時刻および最終更新日をセットする
- getlastmod() - 最終更新時刻を取得する
＋add a note
User Contributed Notes 30 notes
geeks at geekman dot info ¶
16 years ago
This is a very handy function for dealing with browser caching. For example, say you have a stylesheet and you want to make sure everyone has the most recent version. You could rename it every time you edit it, but that would be a pain in the ass. Instead, you can do this:
<?php
echo '<link rel="stylesheet" type="text/css" href="style.css?' . filemtime('style.css') . '" />';
?>
Sample output:
<link rel="stylesheet" type="text/css" href="style.css?1203291283" />
By appending a GET value (the UNIX timestamp) to the stylesheet URL, you make the browser think the stylesheet is dynamic, so it'll reload the stylesheet every time the modification date changes.
paranoid at dds dot nl ¶
21 years ago
To get the last modification time of a directory, you can use this:
<pre>
$getLastModDir = filemtime("/path/to/directory/.");
</pre>
Take note on the last dot which is needed to see the directory as a file and to actually get a last modification date of it.
This comes in handy when you want just one 'last updated' message on the frontpage of your website and still taking all files of your website into account.
Regards,
Frank Keijzers
habazi at yahoo dot com ¶
19 years ago
"this is not (necessarily) correct, the modification time of a directory will be the time of the last file *creation* in a directory (and not in it's sub directories)."
This is not (necessarily) correct either. In *nix the timestamp can be independently set. For example the command "touch directory" updates the timestamp of a directory without file creation.
Also file removal will update the timestamp of a directory.
solarijj at gmail dot com ¶
17 years ago
To get the modification date of some remote file, you can use the fine function by notepad at codewalker dot com (with improvements by dma05 at web dot de and madsen at lillesvin dot net).
But you can achieve the same result more easily now with stream_get_meta_data (PHP>4.3.0).
However a problem may arise if some redirection occurs. In such a case, the server HTTP response contains no Last-Modified header, but there is a Location header indicating where to find the file. The function below takes care of any redirections, even multiple redirections, so that you reach the real file of which you want the last modification date.
hih,
JJS.
<?php
// get remote file last modification date (returns unix timestamp)
function GetRemoteLastModified( $uri )
{
// default
$unixtime = 0;
$fp = fopen( $uri, "r" );
if( !$fp ) {return;}
$MetaData = stream_get_meta_data( $fp );
foreach( $MetaData['wrapper_data'] as $response )
{
// case: redirection
if( substr( strtolower($response), 0, 10 ) == 'location: ' )
{
$newUri = substr( $response, 10 );
fclose( $fp );
return GetRemoteLastModified( $newUri );
}
// case: last-modified
elseif( substr( strtolower($response), 0, 15 ) == 'last-modified: ' )
{
$unixtime = strtotime( substr($response, 15) );
break;
}
}
fclose( $fp );
return $unixtime;
}
?>
MarkAgius at markagius dot co dot uk ¶
3 years ago
filemtime(..) only works with files on your server.
$T=filesize("index.php"); // Works.
$T=filesize("/public_html/dir/index.php"); // Works.
But the following will not work.
$T=filesize("https://mydomain.com/dir/index.php"); // Will not work. Same domain but using web address.
$T=filesize("https://otherdomain.com/dir/index.php"); // Other domain, will not work.
To get file date for other sites try:
(Note: Time zone may be in G.M.T. and not your local timezone)
$T = getFileDate("https://mydomain.com/dir/index.php");
$T = getFileDate("https://otherdomain.com/dir/index.php");
function getFileDate($filePath){
// Same as filemtime(..) but also works with remote files.
// EG. = print date("j/m/Y, g:i:sa (e)",getFileDate("https://abc.com/file.jpg"));
// File not found then will return -307756800 ( 1/04/1960)
$ret = -(3562 *24*60*60); // 1/04/1960 3562= seconds to 1/01/1970
$ch = curl_init($filePath);
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
// Try and get the file modification date.
curl_setopt($ch, CURLOPT_FILETIME, true);
$result = curl_exec($ch);
if($result===false){
die(curl_error($ch));
return $ret;
}
$ret = curl_getinfo($ch, CURLINFO_FILETIME);
curl_close($ch);
return $ret;
}
erelsgl at gmail dot com ¶
14 years ago
Cheaper and dirtier way to code a cache:
<?php
$cache_file = 'URI to cache file';
$cache_life = '120'; //caching time, in seconds
$filemtime = @filemtime($cache_file); // returns FALSE if file does not exist
if (!$filemtime or (time() - $filemtime >= $cache_life)){
ob_start();
resource_consuming_function();
file_put_contents($cache_file,ob_get_flush());
}else{
readfile($cache_file);
}
?>
myselfasunder at gmail dot XYZ dot com ¶
14 years ago
There's a deeply-seated problem with filemtime() under Windows due to the fact that it calls Windows' stat() function, which implements DST (according to this bug: http://bugs.php.net/bug.php?id=40568). The detection of DST on the time of the file is confused by whether the CURRENT time of the current system is currently under DST.
This is a fix for the mother of all annoying bugs:
<?php
function GetCorrectMTime($filePath)
{
$time = filemtime($filePath);
$isDST = (date('I', $time) == 1);
$systemDST = (date('I') == 1);
$adjustment = 0;
if($isDST == false && $systemDST == true)
$adjustment = 3600;
else if($isDST == true && $systemDST == false)
$adjustment = -3600;
else
$adjustment = 0;
return ($time + $adjustment);
}
?>
Dustin Oprea
Anonymous ¶
20 years ago
A comment below states
"When using this function to get the modified date of a directory,
it returns the date of the file in that directory that was last modified."
this is not (necessarily) correct, the modification time of a directory will be the time of the last file *creation* in a directory (and not in it's sub directories).
adam at roomvoter dot com ¶
20 years ago
The snippet of code earlier that allows you to delete all files older than 2 weeks uses the function (filemtime) - which checks the original create date of the file (filesystem independent). You MAY want to use filectime() - that looks at when the file was last changed on YOUR file system.
if (is_dir("$path") )
{
$handle=opendir($path);
while (false!==($file = readdir($handle))) {
if ($file != "." && $file != "..") {
$Diff = (time() - filectime("$path/$file"))/60/60/24;
if ($Diff > 14) unlink("$path/$file");
}
}
closedir($handle);
}
_michael ¶
14 years ago
While testing on Windows, I noticed that the precision of filemtime is just 1 second.
So if you use clearstatcache() and filemtime() to check if a file has been modified, it might fail to detect the change. The modifications just have to happen within less than a second.
(I ran into this with Apache on Windows XP.)
notepad at codewalkers dot com ¶
19 years ago
i needed the ability to grab the mod time of an image on a remote site. the following is the solution with the help of Joe Ferris.
<?php
function filemtime_remote($uri)
{
$uri = parse_url($uri);
$handle = @fsockopen($uri['host'],80);
if(!$handle)
return 0;
fputs($handle,"GET $uri[path] HTTP/1.1\r\nHost: $uri[host]\r\n\r\n");
$result = 0;
while(!feof($handle))
{
$line = fgets($handle,1024);
if(!trim($line))
break;
$col = strpos($line,':');
if($col !== false)
{
$header = trim(substr($line,0,$col));
$value = trim(substr($line,$col+1));
if(strtolower($header) == 'last-modified')
{
$result = strtotime($value);
break;
}
}
}
fclose($handle);
return $result;
}
// echo filemtime_remote('http://www.somesite.com/someimage.jpg');
?>
wookie at at no-way dot org ¶
21 years ago
Another little handy tool; to get the most recent modified time from files in a directory. It even does recursive directories if you set the $doRecursive param to true. Based on a file/directory list function I saw somewhere on this site. ;)
function mostRecentModifiedFileTime($dirName,$doRecursive) {
$d = dir($dirName);
$lastModified = 0;
while($entry = $d->read()) {
if ($entry != "." && $entry != "..") {
if (!is_dir($dirName."/".$entry)) {
$currentModified = filemtime($dirName."/".$entry);
} else if ($doRecursive && is_dir($dirName."/".$entry)) {
$currentModified = mostRecentModifiedFileTime($dirName."/".$entry,true);
}
if ($currentModified > $lastModified){
$lastModified = $currentModified;
}
}
}
$d->close();
return $lastModified;
}
Will Davies Vasconcelos ¶
13 years ago
Here is a handy script to create a csv file with file names and the date when files in a given folder were inserted:
<?php
header("Pragma: public");
header("Cache-Control: private");
header("Content-Type: text/csv");
header("Content-Disposition: attachment; filename=age-of-files.csv");
$result = array();
$handle = opendir(".");
while ($datei = readdir($handle))
{
if (($datei != '.') && ($datei != '..'))
{
$file = "./".$datei;
if (!is_dir($file))
$result[] = $file;
}
}
closedir($handle);
foreach($result as $r)
if (file_exists($r))
echo substr($r,2).",".date ("m/d/Y", filemtime($r))."\r\n";
?>
Benan Tumkaya (benantumkaya at yahoo) ¶
18 years ago
Here is a small but handy script that you can use to find which files in your server are modified after a date/time that you specify. This script will go through all folders in the specified directory recursively and echo the modified files with the last modified date/time...
//Starts Here
//Put here the directory you want to search for. Put / if you want to search your entire domain
$dir='/';
//Put the date you want to compare with in the format of: YYYY-mm-dd hh:mm:ss
$comparedatestr="2006-08-12 00:00:00";
$comparedate=strtotime($comparedatestr);
//I run the function here to start the search.
directory_tree($dir,$comparedate);
//This is the function which is doing the search...
function directory_tree($address,$comparedate){
@$dir = opendir($address);
if(!$dir){ return 0; }
while($entry = readdir($dir)){
if(is_dir("$address/$entry") && ($entry != ".." && $entry != ".")){
directory_tree("$address/$entry",$comparedate);
}
else {
if($entry != ".." && $entry != ".") {
$fulldir=$address.'/'.$entry;
$last_modified = filemtime($fulldir);
$last_modified_str= date("Y-m-d h:i:s", $last_modified);
if($comparedate < $last_modified) {
echo $fulldir.'=>'.$last_modified_str;
echo "<BR>";
}
}
}
}
}
nieprzeklinaj at gmail dot com ¶
11 years ago
Here's a handy little function for smart cache overriding :)
<?php
function img($src, $alt='', $attr='')
{
if(file_exists($src))
{
$lmod = filemtime($src);
echo '<img src="'.$src.'?lmod='.$lmod.'" alt="'.$alt.'" '.$attr.' />';
}
}
?>
jay at fudge dot org ¶
25 years ago
If you want this functionality for the parent web page you should use getlastmod()
i.e.
<?php echo "Last modified: ".date( "F d Y H:i:s.", getlastmod() ); ?>
within the included page... i.e. as a commont footer include for all pages
Anonymous ¶
15 years ago
Please note that many of the functions below that people have provided to get files modified after a certain time in a directory will NOT get all files on a Windows operating system.
If you copy and paste any file inside the folder or into the folder from another folder (such as images that may be used but aren't going to be modified right away), the modified time is not updated on these copied files, only the creation time.
You need to use filectime with filemtime to assure you get copied files that aren't modified but are obviously new.
Don ¶
9 years ago
To find the oldest file in a directory :
$directory= "C:\\";
$smallest_time=INF;
$oldest_file='';
if ($handle = opendir($directory)) {
while (false !== ($file = readdir($handle))) {
$time=filemtime($directory.'/'.$file);
if (is_file($directory.'/'.$file)) {
if ($time < $smallest_time) {
$oldest_file = $file;
$smallest_time = $time;
}
}
}
closedir($handle);
}
echo $oldest_file;
csnyder at chxo dot com ¶
18 years ago
If PHP's integer type is only 32 bits on your system, filemtime() will fail on files over 2GB with the warning "stat failed". All stat()-related commands will exhibit the same behavior.
As a workaround, you can call the system's stat command to get the modification time of a file:
On FreeBSD:
$mtime = exec ('stat -f %m '. escapeshellarg ($path));
On Linux:
$mtime = exec ('stat -c %Y '. escapeshellarg ($path));
Thanks to "mpb dot mail at gmail dot com" for his/her similar comment on stat().