(PHP 4, PHP 5, PHP 7, PHP 8)
touch — Setzt die Zugriffs- und Modifikationszeit einer Datei
Versucht, die Zugriffs- und Modifikationszeit der im Parameter
filename angegebenen Datei auf
mtime zu setzen. Zu beachten ist, dass die
Zugriffszeit unabhängig von der Anzahl der Parameter immer geändert wird.
Wenn die Datei nicht existiert, wird sie erzeugt.
filenameDer Name der zu ändernden Datei.
mtime
Die Modifikationszeit. Wenn mtime null ist,
wird die aktuelle Systemzeit (time()) verwendet.
atime
Wenn nicht null, wird die Zugriffszeit der angegebenen Datei auf
atime gesetzt. Andernfalls wird sie auf den
Wert des angegebenen Parameters mtime gesetzt.
Wenn beide null sind, wird die aktuelle Systemzeit verwendet.
| Version | Beschreibung |
|---|---|
| 8.0.0 |
mtime und atime
sind jetzt nullbar.
|
Beispiel #1 touch()-Beispiel
<?php
if (touch($filename)) {
echo 'Die Modifikationszeit von ' . $filename
. ' wurde auf die aktuelle Zeit gesetzt.';
} else {
echo 'Entschuldigung, die Änderung der Modifikationszeit von ' . $filename
. ' war nicht möglich.';
}
?>
Beispiel #2 Nutzung von touch() mit dem Parameter mtime
<?php
// Modifikationszeit (eine Stunde in der Vergangenheit)
$time = time() - 3600;
// Ändern der Datei
if (!touch('eine_datei.txt', $time)) {
echo 'Ein Fehler ist aufgetreten ...';
} else {
echo 'Änderung der Modifikationszeit war erfolgreich';
}
?>Hinweis:
Beachten Sie, dass die zeitliche Auflösung bei verschiedenen Dateisystemen unterschiedlich sein kann.
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' );
?>Update the access time without updating the modified time:
Unix command: touch -a filename
PHP: touch(filename, date('U', filemtime(filename)), time())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,$time);At least on Linux, touch will not change the time on a symlink itself, but on the file/directory it points to. The only way to work around this is to unlink the symlink, then recreate it.
It took a bit of searching to discover this. The OS itself provides no way to do it. Many people wondered why anyone would want to do this. I use symlinks inside a web tree to point to files outside the web tree. After a certain length of time has passed, I want the symlinks to die, so the files cannot be successfully hotlinked.To touch a file without being owner, it is much easier:
<?php
function touchFile($file) {
fclose(fopen($file, 'a'));
}
?>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.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.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");
}
}
?>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 itNeat 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;
}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 7.4.5A 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()!