touch
(PHP 4, PHP 5, PHP 7, PHP 8)
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
説明
filename で指定されたファイルの最終更新日を、
mtime で指定された値に
セットしようと試みます。
パラメータの数にかかわらず、アクセス時刻は
常に変更されることに注意しましょう。
ファイルが存在しない場合、ファイルが生成されます。
パラメータ
変更履歴
| バージョン | 説明 |
|---|---|
| 8.0.0 |
mtime
と
atime
は、nullable になりました。
|
例
例1 touch() の例
<?php
if (touch($filename)) {
echo $filename . ' modification time has been changed to present time';
} else {
echo 'Sorry, could not change modification time of ' . $filename;
}
?>
例2 touch() で mtime パラメータを使用する例
<?php
// 作成時刻を、ここでは 1 時間前に設定します
$time = time() - 3600;
// ファイルを作成します
if (!touch('some_file.txt', $time)) {
echo 'おっと、何かがおかしいようです...';
} else {
echo 'ファイルの作成に成功しました';
}
?>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。
＋add a note
User Contributed Notes 14 notes
anon ¶
11 years ago
Note that when PHP is called by f.e. apache or nginx instead of directly from the command line, touch() will not prefix the location of the invoking script, so the supplied filename must contain an absolute path.
With script started from /home/user/www, this will not touch "/home/user/www/somefile":
<?php
touch( 'somefile' );
?>
But this will:
<?php
touch( __DIR__ . '/somefile' );
?>
Charles Belov ¶
18 years ago
Update the access time without updating the modified time:
Unix command: touch -a filename
PHP: touch(filename, date('U', filemtime(filename)), time())
Jeff ¶
16 years ago
I've been trying to set a filemtime into the future with touch() on PHP5.
It seems touch $time has a future limit around 1000000 seconds (11 days or so). Beyond this point it reverts to a previous $time.
It doesn't make much sense but I could save you hours of time.
$time = time()+1500000;
touch($cachedfile,$time);
mrgrier at yahoo dot com ¶
16 years ago
At least on Linux, touch will not change the time on a symlink itself, but on the file/directory it points to. The only way to work around this is to unlink the symlink, then recreate it.
It took a bit of searching to discover this. The OS itself provides no way to do it. Many people wondered why anyone would want to do this. I use symlinks inside a web tree to point to files outside the web tree. After a certain length of time has passed, I want the symlinks to die, so the files cannot be successfully hotlinked.
ernst at cron-it dot de ¶
15 years ago
To touch a file without being owner, it is much easier:
<?php
function touchFile($file) {
fclose(fopen($file, 'a'));
}
?>
chris dot dallaire at csquaredsystems dot com ¶
14 years ago
I needed to use this to touch the /etc/cron.d directory when I updated some files in there. I know the docs say this isn't necessary, but I'm finding that i need to do it in order form my changes to be picked up quickly.
I ran into the permissions error as well and I found that using chmod 777 /etc/cron.d does the trick.
So, you should be able to use the PHP touch function on a directory that has open write access.
Of course, this isn't the most secure approach, but in our application it's not a big deal for that folder to not be super secure.
ddalex at gmail dot com ¶
16 years ago
Actually, Glen is right, PHP won't touch if it is not the current owner of the file, even if the directory and files are writeable by the PHP user.
info at archiwumrocka dot art dot pl ¶
16 years ago
Only way to change modification date in catalogue is to create file in via touch() and dalete it with unlink():
<?php
$dir = 'temp';
$files1 = scandir($dir);
$files1 = array_slice($files1, 2);
foreach ($files1 as $key => $val)
{
if (!is_dir($val)) continue;
if (!touch($val))
{
touch($val . "/plik.txt");
unlink($val . "/plik.txt");
}
}
?>
rf_public at yahoo dot co dot uk ¶
19 years ago
Note: the script to touch a file you don't own will change it's owner so ensure permissions are correct or you could lose access to it
feathern at yahoo dot com ¶
22 years ago
Neat little script that will give you a list of all modified files in a certain folder after a certain date:
$filelist = Array();
$filelist = list_dir("d:\\my_folder");
for($i=0;$i<count($filelist);$i++){
$test = Array();
$test = explode("/",date("m/d/Y",filemtime($filelist[$i])));
//example of files that are later then
//06/17/2002
if(($test[2] > 2001) && ($test[1] > 16) && ($test[0] > 5)){
echo $filelist[$i]."\r\n";
}
clearstatcache();
}
function list_dir($dn){
if($dn[strlen($dn)-1] != '\\') $dn.='\\';
static $ra = array();
$handle = opendir($dn);
while($fn = readdir($handle)){
if($fn == '.' || $fn == '..') continue;
if(is_dir($dn.$fn)) list_dir($dn.$fn.'\\');
else $ra[] = $dn.$fn;
}
closedir($handle);
return $ra;
}
picek dot jaroslav at protonmail dot com ¶
10 months ago
I have found out that setting a negative *mtime* deletes the file. The following code always deletes the file at $path while $touch returns true.
<?php
$path = '/folder/file';
$timestamp = -1;
$touch = touch($path, $timestamp);
?>
Running PHP 7.4.5
centurianii at yahoo dot co dot uk ¶
7 years ago
A better explanation:
For file $file and UNIX time stored in vars $access and $modified
- change only access time
\touch($file, \filemtime($file), $access);
- change only modified time
\touch($file, $modified, \fileatime($file));
- change both access and modified time
\touch($file, $modified, $access);
Seeing the results:
//use a session cookie stored in a custom folder
$file = '/var/www/test_com/session/sess_qfn587cudfpgsijm1bs4d81s75';
echo 'stats for sess_qfn587cudfpgsijm1bs4d81s75<br/>';
\clearstatcache();
echo 'access: '.\date("Y-m-d H:i:s", \fileatime($file)).'<br/>';
echo 'modified: '.\date("Y-m-d H:i:s", \filemtime($file)).'<br/>';
echo 'change access to now, modified +1 hour<br/>';
\touch($x, \filemtime($file)+3600, time());
\clearstatcache();
echo 'access: '.\date("Y-m-d H:i:s", \fileatime($file)).'<br/>';
echo 'modified: '.\date("Y-m-d H:i:s", \filemtime($file)).'<br/>';
Notice the double call to clearstatcache()!